While bloody show is not considered as vaginal bleeding requiring medical intervention, other more serious types of bleeding may visibly present as minor bleeding. [ 10 ]  As such, if any of the following are observed, a more thorough examination is warranted to rule out serious causes of bleeding: [ 10 ] [ 11 ]


Bloody show is not considered abnormal within the context of pregnancy, therefore, no treatment is required. [ 5 ]


If a bloody show occurs too early during a pregnancy, there are a few options to counteract the increased risk of infection and  premature labor . [ 3 ]  Preterm labor occurs when the cervix opens after week 20 of pregnancy and before week 37. [ 19 ]  These options include de-stressing such as bed rest, avoiding intense activities, monitoring for signs of active labor, and stitching the cervix closed. Sometimes, the cervix will be stitched closed to help prevent infection or pathogenic harm to the fetus while it develops. Management of the beginning of labor, after the bloody show, can include breathing techniques and hydration to maintain relaxation before delivering the baby. [ 20 ]


Labor begins with the suppression of the inhibitory effects on  myometrium  contraction, leading to dilation of the cervix and pushing the fetus through the birth canal. [ 21 ]  This occurs as intrauterine biochemical events lead to the softening and dilation of the cervix.  Decidual cells , which play a nutritional role in the formation of the placenta, promote the synthesis and release of prostaglandins and proinflammatory cytokines.  Prostaglandins  are key in the onset of childbirth, as they synchronize uterine activation and cervical ripening. [ 22 ]  In some pregnant individuals, hemorrhaging of blood vessels in the cervix may lead to a premature release of prostaglandins. Alongside prostaglandin, placental  oxytocin  is another key naturally occurring neuropeptide released at the onset of labor. Oxytocin can induce myometrial contractions, as it is a common tool used for augmentation of contractions after the onset of labor. [ 23 ]


Cyclic nucleotides, including cyclic guanosine monophosphate ( cGMP ) and cyclic adenosine monophosphate ( cAMP ), activate specific protein kinases to provide rapid intracellular responses to these neuropeptides. Cyclic GMP mediates nitric oxide in the myometrium, allowing the relaxation of the uterus. Cyclic AMP influences the relaxation of myometrial smooth muscle by complexing with adenylyl cyclase ( ADCY ), protein kinase A ( PKA ), and  phosphodiesterases . [ 22 ]


Through this biochemical cascade, a pregnant individual is prepared for childbearing. Vaginal mucus, or  vaginal discharge , may increase in quantity as pregnancy progresses. [ 24 ]  While vaginal mucus is considered normal in individuals with female genitalia, pregnant individuals may notice streaks of blood or a red hue in their vaginal mucus. As the cervix  effaces  and  dilates  in preparation for childbearing, small blood vessels in the cervix may tear and bleed, leading to blood mixed with vaginal mucus from the displaced  mucus plug . [ 25 ]  The mucus plug [ 26 ]  is a blockage of the cervix made up of mucus which acts as a physical barrier against infectious agents that may cause bacterial vaginosis or harm to the fetus. It also contains many antimicrobial agents, similarly to the mucus found in the human nasal cavity. The mucus plug develops during pregnancy to provide a pathogen-free uterus to house the fetus. [ 27 ]  When a mucus plug detaches, a bloody show can be initiated. [ 28 ]  As the blood vessels in the cervix dilate, this leads to ruptures of membranes that allow blood and amniotic fluid to gather in the posterior vaginal canal. [ 25 ]


Although the bloody show can occur as part of the natural progression of labor, activities such as sexual intercourse, pressure on the pelvis, or trauma can initiate the occurrence of bloody show and labor. [ 5 ]  Risk factors that can increase the chance of preterm labor and of having a bloody show include preeclampsia [ 29 ]  and birth complications that risk the health of the mother or fetus. [ 30 ]  Risk factors for preterm pregnancy such as high blood pressure, blood clotting issues, diabetes, sexually transmitted infections, or other vaginal infections may also put the mother at a high risk of an early bloody show.  [ 31 ]


Bloody show was first mentioned in an article back in 1995. [ 32 ]


The  Bradley method of natural childbirth  (also known as "husband-coached childbirth") is a method of  natural childbirth  developed in 1947 by Robert A. Bradley, M.D. (1917–1998) and popularized by his book  Husband-Coached Childbirth ,  first published in 1965. The Bradley method emphasizes that birth is a natural process: mothers are encouraged to trust their body and focus on diet and exercise throughout pregnancy; and it teaches couples to manage labor through deep breathing and the support of a partner or labor coach. [ 1 ]


Teachers of the Bradley method believe that—with adequate preparation, education and help from a loving, supportive coach—most women can give birth naturally, without drugs or surgery. The Bradley method emphasizes measures that can be taken to help keep women healthy and lower their risk for  complications  that may lead to medical intervention.


The primary goal of the Bradley method is healthy mothers and healthy babies. The method holds that, in most circumstances, a natural (drug-free) childbirth is the best way to achieve that goal. Proponents of the Bradley Method claim that 86 percent of mothers who follow the method have vaginal births without drugs. [ 2 ]


Classes teach  nutrition ,  relaxation  and natural breathing as  pain management  techniques, along with active participation of the husband as coach. Parents-to-be are taught to be knowledgeable consumers of birth services and to take responsibility in making informed decisions regarding procedures, attendants and the birthplace.


The method itself is an application of what Dr. Bradley termed "the six needs of the laboring woman": deep and complete relaxation and abdominal breathing; quiet, darkness and solitude; physical comfort; and closed eyes and the appearance of sleep. The method relies heavily on training fathers to be labor "coaches" or partners. Bradley method teachers usually supplement these primary techniques with training in different labor positions and comfort measures. In order to master the ability to relax completely as a pain relief tool, couples are taught several different relaxation techniques and encouraged to practice relaxation daily, so that the mother can rely on a conditioned relaxation response to her partner's voice and touch.


Robert Bradley entered the field of obstetrics in 1947, at a time when mothers were restrained in hospital beds and unable to freely move throughout labor due to the medication they were administered. [ 3 ]  Terming this practice as "knock-em-out, drag-em-out obstetrics", when " twilight sleep " and  general anesthesia  were common in hospital deliveries, Bradley decided to develop his own method. Having been raised on a farm and witnessed many animal births as a part of farm life, Bradley believed that women, like the non-human animals he had observed growing up, could give birth without drugs or distress. Based on observations of mammals during labor and birth, he developed a childbirth method to teach women to do the things that animal mothers do instinctively.


Soon after starting to implement his new childbirth method with pregnant nurses as a trial, Dr. Bradley began to believe that the presence and support of the father during labor and birth was important to the mother's success in achieving a natural birth. He became a pioneer in including fathers in the birth process and eventually expanded his childbirth method to include extensive instruction of the father as labor coach.


Bradley Method instructors are certified by the American Academy of Husband-Coached Childbirth (AAHCC). [ 2 ]


Søren Brostrøm  (born 4 June 1965) is a Danish  physician-scientist  specializing in  obstetrics and gynaecology , who serves as the current  Director general  of the  Danish Health Authority . In May 2021, Brostrøm was elected a member of the  Executive Board  of the  World Health Organization  by the  World Health Assembly . [ 1 ] [ 2 ]


Brostrøm has previously been a member (from 2017), Vice-chair (from 2018), and  Chair  (from 2019), of the Standing Committee of the  European Regional Committee  (SCRC), [ 3 ]  as well as ( ex officio ) Deputy  Executive president  of the WHO Regional Committee for Europe (69th session; 2019–2020). [ 4 ]  He held these posts during the  COVID-19 pandemic , and as chairperson he led the committee's crisis management and response. [ 5 ] [ 6 ] [ 4 ]


Before becoming director general in 2015, Brostrøm served, from September 2011, as the Director of the Department of  Hospitals  and  Emergency management , also at the  Danish Health Authority . Brostrøm worked as a  chief physician  at  Herlev Hospital  and as an  associate professor  at the  University of Copenhagen , before joining the Danish Health Authority. [ 7 ]


Following the  COVID-19 pandemic , Brostrøm became a prominent public figure in Denmark, [ 8 ]  where he played a key role in the Danish response to COVID-19, which has been described as "one of the most successful in  Europe ." [ 9 ] [ 10 ] [ 11 ] [ 12 ]  In Denmark, he became widely known as the " corona   general ", [ 8 ] [ 13 ] [ 14 ] [ 15 ] [ 16 ]  and was especially praised for his "directness and clarity with which he speaks" and his reliance on facts and logic. [ 17 ] [ 18 ]


Søren Brostrøm was born in  Aarhus  in 1965, the second son of two medical doctors; his mother a  paediatrician  and his father a cancer researcher. He grew up in  Risskov  and  Farsø . His father died in an accident when Brostrøm was 11 years old, and the family moved to  Mobile , Alabama, where Brostrøm experienced different social conditions. [ 14 ]  Brostrom said in a 2020-interview that "the tragedy has left an everlasting mark on me" and that life after his father's death was burdened by "both grief and a tough financial situation". [ 19 ]


In the early 1980s, Søren Brostrøm was the international secretary of the  Danish Communist Youth League . [ 14 ]  Brostrøm graduated from  Gammel Hellerup Gymnasium  [ da ]  in 1984. [ 20 ]


From an early age, he was interested in  biology  and mathematics. Brostrøm has said in connection with his profession and education that "although my parents were doctors, it was my own choice, but I was probably also very influenced by them." [ 21 ]


In 1995, Brostrøm received a Master of Science in Medicine ( cand. med. ) [ 22 ]  degree from the  University of Copenhagen . He completed his  clinical clerkship  at  Holstebro Hospital  [ da ]  in  Holstebro , Denmark. [ 20 ]  In 2003, he obtained his  PhD degree  in  obstetrics and gynaecology , with a  subspecialization  in  urogynecology , focused on  laparoscopic   pelvic  surgery. [ 23 ] [ 24 ] [ 25 ]  He completed a  Master of Public Administration  from the  Copenhagen Business School  in 2011. [ 26 ]  In 2019, he completed a Senior Managers in Government (SMG) program at  Harvard Kennedy School of Government . [ 27 ]


His  PhD thesis  was on motor  evoked potentials  from the  pelvic floor  and  lower urinary tract dysfunction . [ 28 ]


He made a career in several Copenhagen hospitals as a  gynaecological surgeon  and was one of the leading doctors in Europe in performing a special  robotic-assisted operation  in which the top of the  vagina  is stitched open. [ 29 ]


After his medical training, Brostrøm worked in 2007 as an  attending physician  at the gynaecological-obstetric department at  Aarhus University Hospital Skejby . He then worked as a  chief physician  at the gynaecological-obstetric department at  Glostrup Hospital  from 2007 to 2008. From 2009 to 2011 he worked as a  chief physician  at the gynaecological-obstetric department at  Herlev University Hospital . [ 30 ]


For two years from 2009 to 2011, Brostrøm worked concurrently as an  associate professor  at the Department of  Gynaecology and Obstetrics  (now part of the Department of Clinical Medicine) at the  Faculty of Health and Medical Sciences  at the  University of Copenhagen , and completed a  Master of Public Administration  (MPA) at  Copenhagen Business School . [ 20 ]


In September 2011, Brostrøm joined the  Danish Health Authority  as the Director of the Department of  Hospitals  and  Emergency management , with broad responsibilities for the national planning of specialized hospital services,  emergency services  and  preparedness ,  communicable diseases ,  immunization  and screening programs as well as national  action plans  in the field of cancer,  cardiovascular diseases ,  mental health  etc. [ 24 ] [ 31 ] [ 26 ]


The responsibilities also included health preparedness and  infectious diseases , which is where the Authority's  pandemic preparedness  lies. During the  COVID-19 pandemic  ten years later, Brostrøm would come to rely on the experience and knowledge he gained as department head. [ 14 ]


In October 2015, Brostrøm was appointed  Director general  of the  Danish Health Authority , which was immediately afterwards heavily reshaped by a comprehensive organizational change, where major areas such as  patient safety ,  approval of medicines  and handling of health data were placed in independent  authorities . [ 32 ] [ 33 ]  The Danish Health Authority remained the overall authority.


One of his first major tasks was to complete the update of the  specialty  plan, which dictates which hospitals can perform complicated treatments and which cannot. It came into force in June 2017 after extensive committee work and many critical debates in medical circles. [ 29 ]


Brostrøm came to public attention when the Danish Health Authority's  HPV   vaccination  programme in 2014–15 experienced a sudden and large drop in uptake among the target group, girls and young women, who feared serious  side effects . Brostrøm took responsibility for inadequate communication and did so in an open and personal manner, which has also been characteristic of his appearance at numerous press conferences and interviews in connection with the handling of the  COVID-19 pandemic . [ 29 ]


Brostrøm is interested in art, theatre and the opera. [ 34 ]  Brostrøm is openly homosexual. [ 35 ]


Brostrom spoke in an interview in 2020 about how the  HIV and AIDS global epidemic  affected his youth: "HIV and AIDS is the disease I myself grew up with. Both as a young gay man and as a young medical student." [ 35 ]  Brostrøm described how the disease came as a shock and put a damper on the free and uninhibited  sexuality  that had  taken hold in the gay community throughout the 1960s and 70s . [ 35 ]  Brostrøm said, "In 1992 I was in the US as part of (medical) school, and from that period I remember it very clearly. There was a lot of debate and the disease was shrouded in taboo. There were  religious  and  conservative  groups who called HIV and AIDS God's punishment on homosexuals. At that time I saw young beautiful men lying dead. People like myself." [ 35 ]


Brostrøm has been chairman and board member of a number of organizations. List: [ 27 ] [ 34 ] [ 36 ]


Cannabis consumption in pregnancy  is an important  public health issue . Research has found possible or likely associations between cannabis use and a risk of adverse outcomes in respect of cognitive development, mental health, physical health, and lactation. [ 1 ]


Cannabis is the most commonly used controlled substance among pregnant women. [ 2 ]


The role of the endocannabinoid system (ECS) in female fertility has long been suspected and studied. [ 3 ]   Most studies through 2013 linking development of the fetus and cannabis show effects of consumption during the gestational period, but abnormalities in the endocannabinoid system during the phase of placental development are also linked with problems in pregnancy. [ 4 ]  According to Sun and Dey (2012), endocannabinoid signaling plays a role in "female reproductive events, including preimplantation embryo development, oviductal embryo transport, embryo implantation, placentation, and parturition". [ 3 ]   Karusu  et al  (2011) said that a "clear correlation ... in the actual reproductive tissues of miscarrying versus healthy women has yet to be established. However, the adverse effects of marijuana smoke and THC on reproductive functions point to processes that are modulated by ECS.". [ 5 ]


Recent data indicates that endometrial expression of cannabinoid receptors in marijuana smoking mothers is higher than non-smokers. [ 6 ]  Keimpema and colleagues (2011) said, "Prenatal cannabis exposure can lead to growth defects during formation of the nervous system"; "[c]annabis impacts the formation and functions of neuronal circuitries by targeting cannabinoid receptors ... By indiscriminately prolonging the "switched-on" period of cannabinoid receptors, cannabis can hijack endocannabinoid signals to evoke molecular rearrangements, leading to the erroneous wiring of neuronal networks". [ 7 ]   A report prepared for the  Australian National Council on Drugs  concluded cannabis and other  cannabinoids  are contraindicated in pregnancy as they may interact with the endocannabinoid system. [ 4 ] [ 8 ]


As of 2023 [update]  the rising use of cannabis during pregnancy, and the rise in cannabis potency, has become an important  public health issue . Research has found possible or likely associations between cannabis use and a risk of adverse outcomes in respect of cognitive development, mental health, physical health, and lactation. [ 1 ]


Cannabis use during pregnancy is associated with adverse effects on the  mental health  and  cognitive performance  of offspring. [ 9 ]  The THC exposure resulting from cannabis use interferes with fetal brain development and the male offspring of users are more susceptible to psychotic illness. [ 10 ]


THC exposure in rats during the prenatal developmental phase may cause  epigenetic  changes in gene expression, but there is limited knowledge about the risk for psychiatric disorders because of ethical barriers to studying the developing human brain. [ 11 ]  A 2015 review found that cannabis use by pregnant mothers corresponded to impaired brain maturation in their children, and that those children were more predisposed to  neurodevelopmental disorders ; these results do not demonstrate causality. [ 12 ]


The  National Institute on Drug Abuse  stated in 2018 that further research is required to "disentangle" effects of cannabis use from a mother's concomitant drug use and other environmental factors. [ 13 ]


Developmental observations suggest that CB1 receptors develop only gradually during the  postnatal period , which block for the  psychoactive  effects of cannabinoid treatment in the young organism. Therefore, it is suggested that children may respond positively to medicinal applications of cannabinoids without undesirable central effects. Clinical results have been reported in  pediatric oncology  and in case studies of children with severe  neurological disease  or  brain trauma , and  cystic fibrosis  (CF) suggesting cannabinoid treatment for  children  or  young adults , in order to achieve an improvement of their health condition including improved food intake and reduced  inflammatory  exacerbations. [ 14 ]


Hyperemesis Gravidarum  (HG), is a debilitating ailment characterized by severe  nausea  and  vomiting ,  malnutrition , and  weight loss  during pregnancy, and occurs to 1-2% of pregnant women  globally . It is a perplexing female mystery for the present-day medical establishment. The frustration is mostly felt by women who are survivors of HG, desperately searching for a cure and increased understanding of this disease. Several pregnant women have revealed their personal experience with cannabis, having used it to relieve symptoms of HG, who would otherwise have become severely  emaciated ,  dehydrated , and malnourished due to persistent, uncontrollable vomiting and the inability to eat and  drink  in their pregnancy. [ 15 ] [ 16 ]


It is a common misconception that cannabis use in pregnancy is low risk; a 2015 study found that 70% of women in the  United States  assume that using cannabis 1-2 times a week while pregnant is safe. [ 17 ]


A  caul  is a piece of  membrane  that can cover a  newborn 's head and face. [ 1 ]  Birth with a caul is rare, occurring in less than 1 in 80,000 births. [ 2 ]  The caul is harmless and is immediately removed by the attending parent, physician, or  midwife  upon birth of the child. [ citation needed ]


An en-caul birth is different from a caul birth in that the infant is born inside the entire  amniotic sac  (instead of just a portion of it). The sac balloons out at birth, with the amniotic fluid and child remaining inside the unbroken or partially broken membrane. [ citation needed ]


A child 'born with the caul' has a portion of a birth membrane remaining on the head. There are two types of caul membranes, [ clarification needed ]  and such cauls can appear in four ways. [ clarification needed ] [ citation needed ]


The most common caul type is a piece of the thin translucent inner lining of the  amnion  that breaks away and forms tightly against the head during birth. [ 3 ]  Such a caul typically clings to the head and face but on rarer occasions drapes over the head and partly down the torso. [ citation needed ]


The caul is harmless and is immediately removed by the attending parent,  physician , or  midwife  upon birth of the child. If the membrane is of the amniotic tissue, it is removed by easily slipping it away from the child's skin. The removal of the thicker membrane is more complex. If done correctly, the attending practitioner will make a small incision in the membrane across the nostrils so that the child can breathe. The loops are then carefully removed from behind the ears. The remainder of the caul is then either peeled back very carefully from the skin or else gently rubbed with a sheet of paper, which is then peeled away. If removed too quickly, the caul can leave wounds on the infant's flesh at the attachment points, which might leave permanent scars. [ 3 ]


Birth with a caul is rare, occurring in fewer than 1 in 80,000 births. This statistic includes en-caul births, which occur more frequently than authentic caul births; therefore, authentic caul births are even more rare than indicated by the raw statistic. Most en-caul births are premature. [ 4 ] [ better source needed ]


According to  Aelius Lampridius , the boy-emperor  Diadumenian  (208–218) was so named because he was born with a  diadem  formed by a rolled caul. [ citation needed ]


In medieval times, the appearance of a caul on a newborn baby was seen as a sign of good luck. [ 5 ]  It was considered an  omen  that the child was destined for greatness. Gathering the caul onto paper was considered an important tradition of childbirth: the midwife would rub a sheet of paper across the baby's head and face, pressing the material of the caul onto the paper. The caul would then be presented to the mother, to be kept as an  heirloom . Some Early Modern European traditions linked caul birth to the ability to defend fertility and the harvest against the forces of evil, particularly witches and sorcerers. [ a ]


Folklore developed suggesting that possession of a baby's caul would bring its bearer good luck and protect that person from death by drowning. Cauls were therefore highly prized by  sailors . Medieval women often sold them to sailors for large sums of money; a caul was regarded as a valuable  talisman . [ 7 ]


In Polish the idiom  w czepku urodzony/a  ('born in a bonnet'), in Italian  nato/a con la camicia  ('born with a shirt') and in French  né(e) coiffé(e)  ('born with a hat on') all describe a person who is always very lucky. [ citation needed ]


The Russian phrase  родился в рубашке  ( rodilsya v rubashke , literally 'born in a shirt') refers to caul birth and means 'born lucky'. It is often applied to someone who is oblivious to an impending disaster that is avoided only through luck, as if the birth caul persists as supernatural armor, and in this sense commonly appears in titles or descriptions of Russian  dashcam  videos. [ citation needed ]


Not all cultural beliefs about cauls are positive. In  Romanian folklore  babies born with a caul are said to become  strigoi  upon death. [ 8 ] [ 9 ]  It was also believed that "he who is born to be hanged will never drown" - that anyone born with a caul was destined to leave the world in a hangman's hood in place of the caul with which they were born. The belief in cauls as omens persisted well into the 20th century. [ 10 ]


The 16th-century Dutch physician  Levinus Lemnius , author of  The Secret Miracles of Nature , remained skeptical of superstitious claims about preserved cauls. Comic writer  Thomas Hood  even ended his poem "The Sea-Spell" with a lament about a drowning sailor's futile reliance on a protection charm: [ 10 ]


Heaven never heard his cry,
Nor did the ocean heed his caul.


In the classic 1850 novel  David Copperfield  by  Charles Dickens , the title character and novel narrator describes his own birth: "I was born with a caul, which was advertised for sale, in the newspapers, at the low price of fifteen guineas." Copperfield goes on to describe the fate of his caul, which was re-sold and raffled over the subsequent decade as a talisman believed to protect its owner from death by drowning. [ 27 ]


In the novel  Oscar and Lucinda  by  Peter Carey , Theophilus Hopkins, father of the hero, Oscar, gives to his son a little box, inside which there is "a caul, the little membrane that had covered Oscar's head at birth and it had been kept, his mother had kept it, because it was said – superstitiously, of course – that such a thing would protect the child from drowning". [ 28 ]


An  en caul  birth is depicted in the episode "Heavy Hangs the Head" (S03E01) of the  Apple TV+   science fiction  series  See . [ 29 ]


Other depictions include:


In  obstetrics , a  cephalic presentation  or  head presentation  or  head-first presentation  is a situation at  childbirth  where the  fetus  is in a  longitudinal lie  and  the   head  enters the pelvis first;  the most common form of cephalic presentation is the vertex presentation, where the  occiput  is the leading part (the part that first enters the  birth canal ). [ 1 ]  All other presentations are abnormal ( malpresentations ) and are either more difficult to deliver or not deliverable by natural means.


The movement of the fetus to cephalic presentation is called  head engagement . It occurs in the  third trimester . In head engagement, the fetal head descends into the  pelvic cavity  so that only a small part (or none) of it can be felt abdominally. The perineum and cervix are further flattened and the head may be felt vaginally. [ 2 ]  Head engagement is known colloquially as the  baby drop , and in natural medicine as the  lightening  because of the release of pressure on the upper abdomen and renewed ease in breathing. However, it severely reduces bladder capacity resulting in a need to void more frequently. [ 3 ]


In the vertex presentation, the head is  flexed  and the  occiput  leads the way. This is the most common configuration and seen at term in 95% of singletons. [ 1 ]  If the head is extended, the  face  becomes the leading part. Face presentations account for less than 1% of presentations at term. In the sinicipital presentation, the large  fontanelle  is the presenting part; with further labor the head will either flex or extend more so that in the end this presentation leads to a vertex or face presentation. [ 1 ]  In the brow presentation, the head is slightly extended, but less than in the face presentation. The chin presentation is a variant of the face presentation with maximum extension of the head.


Non-cephalic presentations are the  breech presentation  (3.5%) and the  shoulder presentation  (0.5%). [ 1 ]


The vertex is the area of the vault bounded anteriorly by the anterior fontanelle and the coronal suture, posteriorly by the posterior fontanelle and the lambdoid suture and laterally by 2 lines passing through the parietal eminences.


In the vertex presentation, the occiput typically is anterior and thus in an optimal position to negotiate the  pelvic  curve by extending the head. In an occiput posterior position, labor becomes prolonged, and more operative interventions are deemed necessary. [ 4 ]  The prevalence of the persistent occiput posterior is given as 4.7%. [ 4 ]


The vertex presentations are further classified according to the position of the  occiput , both right, left, or transverse and anterior or posterior:


The occipito-anterior position is ideal for birth; it means that the baby is lined up so as to fit through the pelvis as easily as possible. The baby is head down, facing the spine, with their back anterior. In this position, the baby's chin is tucked onto their chest, so that the smallest part of their head will be applied to the cervix first. The position is usually "Left Occiput Anterior", or LOA. Occasionally, the baby may be "Right Occiput Anterior", or ROA. [ 5 ]


Factors that predispose to face presentation are  prematurity ,  macrosomia ,  anencephaly  and other malformations,  cephalopelvic disproportion , and  polyhydramnios . [ 6 ] [ 7 ]  In an uncomplicated face presentation, duration of labor is not altered. Perinatal losses with face presentation occur with traumatic  version and extraction  and  midforceps  procedures [ 7 ]  Duff indicates that the prevalence of face presentations is about 1/500–600, [ 7 ]  while Benedetti et al. found it to be 1/1,250 term deliveries. [ 8 ]


Face presentations are classified according to the position of the  chin  (mentum):


While some consider the brow presentation as an intermediate stage towards the face presentation, [ 1 ]  others disagree. Thus Bhal et al. indicated that both conditions are about equally common (1/994 face and 1/755 brow positions), and that prematurity was more common with face while  postmaturity  was more common with brow positions. [ 9 ]


The piriform ( pear -shaped) morphology of the  uterus  has been given as the major cause for the finding that most singletons favor the cephalic presentation at term. [ 1 ]  The  fundus  is larger and thus a fetus will adapt its position so that the bulkier and more movable podalic pole makes use of it, while the head moves to the opposite site. Factors that influence this positioning include the  gestational  age (earlier in gestation breech presentations are more common as the head is relatively bigger), size of the head, malformations, amount of  amniotic fluid , presence of multiple gestations, presence of tumors, and others.


Usually performing the  Leopold maneuvers  will demonstrate the presentation and possibly the position of the fetus. [ 10 ]   Ultrasound examination  delivers the precise diagnosis and may indicate possible causes of a malpresentation. On vaginal examination, the leading part of the fetus becomes identifiable after the  amniotic sac  has been broken and the head is descending in the pelvis.


Many factors determine the optimal way to deliver a baby. A vertex presentation is the ideal situation for a vaginal birth, although occiput posterior positions tend to proceed more slowly, often requiring intervention in the form of  forceps , vacuum extraction, or  caesarean section . [ 4 ]  In a large study, a majority of brow presentations were delivered by caesarean section, however, because of 'postmaturity', factors other than labour dynamics may have played a role. [ 9 ]  Most face presentations can be delivered vaginally as long as the chin is anterior; there is no increase in fetal or maternal mortality. [ 11 ]  Mento-posterior positions cannot be delivered vaginally in most cases (unless rotated) and are candidates for caesarean section in contemporary management. [ 11 ]


Cerebroplacental ratio  is a tool used in obstetric  ultrasound  to predict adverse pregnancy outcome. [ 1 ]  It is measured by dividing the  pulsatility index  of the middle cerebral artery of the foetus by the pulsatility index of the umbilical artery of the foetus. A cerebroplacental ratio lower than 1-1.1 in uncomplicated pregnancies is indicative of placental insufficiency, independent of the actual fetal size. [ 2 ] [ 3 ]


Cervical dilation   (or cervical dilatation) is the opening of the  cervix , the entrance to the uterus, during  childbirth ,  miscarriage ,  induced abortion , or gynecological surgery.  Cervical dilation may occur naturally, or may be induced surgically or medically.


In the later stages of pregnancy, the cervix may already have opened up to 1–3 cm (or more in rarer circumstances), but during  labor , repeated  uterine contractions  lead to further widening of the cervix to about 6 centimeters.  From that point, pressure from the presenting part (head in vertex births or bottom in breech births), along with uterine contractions, will dilate the cervix to 10 centimeters, which is "complete." Cervical dilation is accompanied by  effacement , the thinning of the cervix.


General guidelines for cervical dilation:


During  pregnancy , the os (opening) of the cervix is blocked by a thick plug of  mucus  to prevent bacteria from entering the uterus. During dilation, this plug is loosened. It may come out as one piece, or as thick mucus discharge from the vagina. When this occurs, it is an indication that the cervix is beginning to dilate, although not all women will notice this mucus plug being released.


Bloody show  is another indication that the cervix is dilating. Bloody show usually comes along with the mucus plug, and may continue throughout labor, making the mucus tinged pink, red or brown. Fresh, red blood is usually not associated with dilation, but rather serious complications such as  placental abruption , or  placenta previa .  Red blood in small quantities often also follows an exam.


The pain experienced during dilation is similar to that of  menstruation  (although markedly more intense), as period pains are thought to be due to the passing of  endometrium  through the cervix. Most of the pain during labor is caused by the uterus contracting to dilate the cervix.


Prostaglandins  (P2 and  PGE2 ) contribute to cervical ripening and dilation [ 1 ] . The body produces these hormones naturally. Sometimes prostaglandins in synthesized forms are applied directly to the cervix to induce labor. [ 2 ]   In women who have had a previous  caesarean section , the  American College of Obstetricians and Gynecologists  issued a bulletin that  misoprostol  never be used for this purpose. ACOG's findings conclude that the collagen softening properties of misoprostol could be absorbed through the cervix and vaginal vault up into the low transverse scar of a typical caesarean section, and significantly increase the risk of uterine rupture. [ 3 ] [ obsolete source ]   Prostaglandins are also present in human  semen , and  sexual intercourse  is commonly recommended for promoting the onset of labor, although the limited data available makes the effectiveness of this method uncertain. [ 4 ]


Other means of natural cervical ripening include  nipple stimulation , which produces  oxytocin , a hormone which is necessary for uterine contractions. Nipple stimulation can be performed manually, by use of a  breast pump , or by suckling. Henci Goer, in her comprehensive book, The Thinking Woman's Guide to a Better Birth, details how this practice was researched in two separate studies of 100 and 200 women in the mid nineteen-eighties. Women were assigned randomly to two groups. In one group, nipples were stimulated for one-hour sessions, three times per day. In the other group, women were to avoid any form of nipple stimulation or sexual intercourse. The researchers concluded in both studies that nipple stimulation could indeed ripen the cervix and in some cases induce  uterine contractions . Goer further notes that in the smaller study, an  external fetal monitor  was used, and no  uterine hyperstimulation  was noted. [ 5 ] [ unreliable source ]


Cervical dilation may be induced mechanically by placing devices inside the cervix that will expand while in place.  A  balloon catheter  may be used.  Other products include  osmotic dilators , such as  laminaria  stick (made of dried seaweed) or synthetic  hygroscopic  materials, which expand when placed in a moist environment. [ 2 ]


Results from 2021 systematic reviews of the literature found no differences in  caesarean  delivery, neonatal, nor maternal outcomes between inpatient or outpatient  cervical ripening . [ 6 ] [ 7 ]


In treatment of  spontaneous  or  induced abortion , preparation (softening and dilating) of the cervix allows the cannulae  vacuum aspiration  to pass more easily into the uterus, which may make the procedure shorter in duration, more comfortable for the patient, and easier to perform. [ 8 ] [ 9 ]  Preparation may also reduce the rare complications of uterine perforation and cervical injury. [ 8 ] [ 10 ]  Options for cervical preparation prior to the abortion procedure include osmotic dilators and pharmacologic agents. Osmotic dilators produce wide cervical dilation in a predictable fashion and are generally used in more advanced pregnancies. [ 8 ] [ 10 ]  Pharmacologic agents, such as  misoprostol  and  mifepristone , soften the cervix and facilitate cervical dilation, and may be used alone in early pregnancy, or in combination with osmotic dilators prior to  dilation and evacuation . [ 8 ] [ 10 ]


In  hysteroscopy , the diameter of the hysteroscope is generally too large to conveniently pass the  cervix  directly, thereby necessitating cervical dilation to be performed prior to insertion. Cervical dilation can be performed by temporarily stretching the cervix with a series of  (cervical) dilators  of increasing diameter. [ 11 ]   Misoprostol  prior to hysteroscopy for cervical dilation appears to facilitate an easier and uncomplicated procedure only in premenopausal women. [ 12 ]


Cervical effacement  or  cervical ripening  refers to the thinning and shortening of the cervix. This process occurs during  labor  to prepare the  cervix  for dilation to allow the fetus to pass through the vagina. While this is a normal, physiological process that occurs at the later end of pregnancy, it can also be induced through medications and procedures. [ 2 ]


During  gestation , the cervix maintains pregnancy by increasing synthesis of various  proteins . These proteins have defined interactions that allow the formation of matrix proteins to help fortify the uterine cervix. [ 3 ]  Toward the end of  pregnancy , a series of hormone-mediated biochemical process takes place to degrade the collagen and fiber network to cause the cervix to ripen during labor. Failure to ripen the cervix during labor may delay its onset and cause complications. [ 4 ]  Current efforts to induce labor include  pharmacologic ,  non-pharmacologic ,  mechanical  and  surgical  methods.


Cervical ripening has primarily been performed in the inpatient setting. Due to a variety of reasons, such as cost and patient preference, the capacity to undergo outpatient cervical ripening is being explored. [ 5 ]


Prior to effacement, the cervix is like a long bottleneck, usually about four centimeters in length. Throughout  pregnancy , the cervix is tightly closed and protected by a plug of  mucus . Effacement is accompanied by  cervical dilation . When the cervix effaces, the mucus plug is loosened and passes out of the  vagina . The mucus may be tinged with  blood  and the passage of the mucus plug is called  bloody show  (or simply "show"). As effacement takes place, the cervix then shortens, or effaces, pulling up into the uterus and becoming part of the lower uterine wall.


Further Information:   Signaling Pathways Regulating Human Cervical Ripening in Preterm and Term Delivery [ 6 ]


Histologically, the cervix undergoes significant changes towards the end of gestation, allowing the ripening of cervix for the passage of birth delivery. First, there is an increase in the cervical synthesis of  glycosaminoglycan  hyaluronan (HA), which increases tissue hydration, thereby catalyzing the degradation of collagen and elastin-fibers. Second, there is an increase in the secretion of matrix metalloproteinases that also act to digest components of the extracellular matrix, including  proteoglycans ,  laminin , and  fibronectin , which are found in the cervical stroma ( parametrium ). [ 7 ]  Third, due to the nature of the cervical effacement process, enzymes and other mediators that regulate allergic and inflammatory responses are also involved. [ 6 ]  One of the immunomodulating factors,  mast cells , is known to secrete inflammatory mediators that modulate the process of cervical ripening through mast cell degranulation. [ 8 ]   Histamine , one of the allergenic mediators released by mast cells, has shown to have causative relationship with cervical smooth muscle contractility. However, the research is not complete. [ 6 ]


The  Bishop score  is the most common method of assessing the need for induction of labor. The scoring is based on a  digital cervical exam  and takes into consideration  cervical dilation , position, effacement, consistency of the  cervix  and fetal station.  [ 10 ]


Cervical dilation, effacement and station are scored from 0 to 3. Cervical consistency and position are scored from 0 to 2. The total score ranges with a minimum of 0 and maximum of 13. A Bishop score of 6 and below indicates that induction is not favorable and no method of induction will be highly effective. In these cases, cervical ripening agents may be used. A score of 8 and above indicates induction of labor is favorable and the possibility of a  vaginal delivery  with induction will be similar to spontaneous labor.  [ 10 ]


Cervical effacement is an important component of the Bishop score and is reported as a percentage. 0% indicates the cervix is at normal length, 50% indicates the cervix is half of the expected length and 100% effaced means the cervix is paper thin.  [ 10 ]


The Bishop score has been modified in current medical practice. The modified scoring method takes into consideration only 3 parameters: dilation, effacement, and fetal station. These are scored between the range of 0 to 3 each with a score of 5 or above being favorable for induction of labor.  [ 10 ]


Given that cervical effacement is measured as a percentage, this method requires a consensus on a standard uneffaced cervix length. However, this can vary among physicians. This requirement presents itself as an opportunity for error, miscommunication and inappropriate care in the process of assessing cervical effacement. Other methods used in assessing and measuring cervical effacement may be more accurate than the Bishop score, such as the metric system of measuring the cervix. Integrating the metric system of measurement of the cervix may reduce and eliminate the risk of error and assumptions on cervical length.  [ 11 ]


Imaging methods are also being considered to measure cervical effacement.  Elastography  measures the stiffness and ability of soft tissue and can be used to assess how the cervical tissue deforms under pressure. This cannot be assessed manually and can be a useful parameter in predicting a  preterm  or full term delivery. There are two methods of elastography. Static elastography measures the tissue displacement in response to manual compression or movement. Dynamic elastography measures speed of shear wave propagation.   [ 12 ]  Both methods can provide useful information on the stiffness of the cervix in considering induction of labor.


Cervical ripening is contraindicated in pregnancies presenting with the following conditions: [ 13 ]


The contraindications for cervical ripening also include those of  vaginal birth . [ 15 ]  Absolute contraindications can result in life-threatening events, and relative contraindications should be considered with caution. The absolute and relative contraindications to  vaginal birth  include, but are not limited to the following:


Absolute contraindications: [ 15 ]


Relative contraindications: [ 15 ]


Labor induction poses different risks to the woman and fetus. As such, risks and complications relating to cervical effacement can be classified as being a risk to the woman or the fetus.


Cervical ripening via transcervical balloon catheter can increase the risk of infection to the woman. Approximately 11% of pregnancies develop an intrapartum infection, 3% a postpartum infection and 5% a neonatal infection. Only intrapartum infection was deemed a clinically significant risk.  [ 16 ]


The risk of  uterine hyperstimulation  as it relates to labor induction is higher with dinoprostone and vaginally administered misoprostol than it is with oxytocin and mechanical methods. [ 17 ]


Oxytocin dysregulation has been linked to  Autism or autism spectrum disorder . As oxytocin is one of the methods used for cervical ripening, the Committee on Obstetric Practice at the  American College of Obstetricians and Gynecologists  conducted a review of existing research regarding this link, and concluded that there was insufficient evidence of a causal link between cervical effacement via oxytocin and autism/ASD.  [ 18 ]


Low dose oral misoprostol for the purpose of labor induction, is associated with a lower risk of  fetal distress  than vaginally administered misoprostol.  [ 19 ]


Vaginally administered  dinoprostone  is associated with an increased risk of fetal hyperstimulation with or without fetal heart rate abnormalities.  [ 17 ]


Inpatient and outpatient cervical ripening done via vaginally administered  dinoprostone  or  balloon catheters  in low risk pregnancies do not have different rates of  caesarean section . [ 2 ]  Cervical ripening using  dinoprostone  vaginal inserts have the same rates of neonatal morbidity,  caesarean section , and labor onset when used in the outpatient setting and the inpatient setting. [ 20 ]  Evidence for use of misoprostol in the outpatient versus inpatient setting was insufficient to draw conclusions.  [ 21 ]


Oxytocin is one of the most commonly used medications for cervical effacement. It is given as an infusion to either start or increase  uterine contractions .  Epidurals  are often used together for pain. Oxytocin may also be used in the setting of  amniotomy  as well as balloon catheters to further contractions in conjunction to these procedures.


Misoprostol is a medication that can cause contractions for cervical effacement. When used with balloon catheters, vaginal delivery was more likely to occur within the next 24 hours after initiation. It is known as a type of  prostaglandin  and available worldwide. It can also be used for early termination of pregnancy.


Also in the class of prostaglandins, dinoprostone increases contractions. It is available in both gel and vaginal insert form and while both are safe and efficacious, one study has found that in those with a bishop score of less than or equal to 4, the vaginal insert seemed to be more effective in spontaneous vaginal delivery by about 20%.


Red raspberry leaf tea is an herbal option for cervical effacement. In a retrospective observational study conducted in 1999, while there was not significant difference in time for second and third stage of labour, the "mean time in first stage of labour is also substantially lower in the raspberry leaf group". The data, however, was not proven to be statistically significant.


Warm bath is a common method used by midwives to ease labor pain and also induce labor. In a study conducted in 2019, "cervical dilation increased in all groups (p<.001), as well as the number of uterine contractions increased, mainly in the group that used combined bath and ball and also showed shorter labor time". Safety precautions should be taken to make sure that the water temperature is not too high as it can lead to fetal distress.


Balloon Catheters are catheters that can be inserted into the cervix in the setting of pregnancy to induce labor. Saline is used to inflate the balloon, causing increased pressure to the cervix. This is to imitate the pressure of a fetal head that would be pressing on the cervix during labor, which in turn speeds up the process.


Hygroscopic dilator is a dilator that is inserted into the cervix and expands in size as it absorbs genital tract moisture. They can also be used for early termination of pregnancy.


According to a study conducted in Japan from 2012-2014, the rate of delivery at term seemed to be equivalent between the group that used balloon catheter and that of the hygroscopic dilator. [ 27 ]


Amniotomy is a procedure where a hook is inserted into the amniotic membranes to puncture, causing the amniotic fluid to drain from the amniotic sac that holds the fetus. The reason for the surgical procedure could either be for cervical effacement or to look at fetal status as a device can be inserted into the amniotic sac for monitoring. The sign of successful procedure is when the amniotic fluid immediately comes out once the membrane is punctured. Certain amniotic fluid colors can indicate fetal distress, which is why it is important for the obstetrician or midwife to check the color.


Membrane stripping, otherwise known as membrane sweeping, is a procedure where the obstetrician inserts a finger into the cervix and moves in a sweeping motion to detach the amniotic membrane from the uterus. It is thought to be different from other procedures in that it is less costly compared to the other. While it may be an inexpensive procedure, it comes with its own risks. Membrane sweeping may rupture the amniotic sac for 1 out of 10 women who get this procedure done, which will then lead for the need to formally induce labor within 24 hours. Membrane sweeping can also be very painful and can cause bleeding and irregular contractions. Membrane sweeping is also not effective for 7 out of the 8 women that get this procedure done.


A  cervical mucus plug  ( operculum ) is a plug that fills and seals the  cervical canal  during pregnancy. It is formed by a small amount of cervical  mucus  that condenses to form a cervical mucus plug during pregnancy. [ 1 ]


The cervical mucus plug (CMP) acts as a protective barrier by deterring the passage of  bacteria  into the  uterus , and contains a variety of antimicrobial agents, including  immunoglobulins , and similar  antimicrobial peptides  to those found in  nasal mucus .The CMP inhibits the migration of vaginal bacteria towards the uterus, protecting against opportunistic infections that can lead to pelvic inflammatory disease and the onset of preterm labor. Ensuring the presence and proper function of the CMP is essential in reducing severe infections and promoting overall reproductive health. [ 1 ]


During  pregnancy , the mucus has  viscoelastic  properties and can be described as cloudy, clear, thick, salty and sticky. It holds innate and adaptive immunity properties allowing for protection of the cervical epithelium during pregnancy. Toward the end of the pregnancy, when the cervix thins, some blood is released into the cervix which causes the mucus to become bloody. As the pregnancy progresses into labor, the cervix begins to dilate and the mucus plug is discharged. The plug may come out as a plug, a lump, or simply as increased  vaginal discharge  over several days.  Loss of the mucus plug does not necessarily mean that delivery or labor is imminent. [ 2 ]


Having  intercourse  or a  vaginal examination  can also disturb the mucus plug and cause a pregnant individuals to see some blood-tinged discharge, even when labor does not begin over the next few days. [ 1 ]


A cervical mucus plug can allow for identification of an individual's ovulation cycle and serve as fertility indicator. The cervical mucus plug  proteome  changes throughout an individual's menstrual cycle and allows for identification of specific proteins that may represent different stages of ovulation. [ 3 ]


Some proteins found within the cervical mucus of patients with endometriosis could serve as potential biomarkers for the disease. [ 3 ]


Cervicovaginal mucus is composed of water, gel-forming-mucins (GFMS), and vaginal flora. GMFS are a combination of proteins and other molecules that are responsible for the viscoelastic properties of the mucus. [ 1 ]  Cervical mucus is formed by secretory cells within the cervical crypts. [ 3 ]


Mucus  glycoproteins  (mucins) provide structural framework for a CMP, they determine the elasticity and fluid mechanics of a cervical mucus plug. [ 2 ]


Mucus within the genital tract serves numerous biological functions such as maintaining mucosa moisture, providing lubrication during intercourse, supporting fertility, and restricting ascending sperm cells during ovulation. [ 1 ]


The mucus glycoproteins (mucins) mentioned previously have five major components. The first is their ligand function for lectins, adhesion molecules, growth factors, cytokines, and chemokines. Second, they are responsible for binding water in CMPs and determines its hydration state. Third, mucins exclude lager molecules and bacteria which prevents bacterial infections in the lower genital tract. Mucins inhibit diffusion of these large molecules, while smaller molecules can diffuse through the CMP more freely. Fourth, mucins are responsible for the retention of positively charged molecules, while negative charged molecules are repelled and pass through the CMP. This is due to the negatively charged  oligosaccharide  chains in the mucins, which promote retention of the positively charged molecules. Lastly, mucins inhibit viral replication of poxvirus and human immunodeficiency virus (HIV) in vitro. In addition, mucins can also create a communication between the CMP and cervical epithelium. [ 2 ]


The cervical mucus plug (CMP) has a viscoelastic structure which is a gel like. The CMP occupies the cervical canal during pregnancy. It displays potent antimicrobial properties against bacteria such as Staphylococcus saprophyticus, S. aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecium, Streptococcus pyogenes, and S. agalactiae.


Naturally occurring Lactobacillus species within the cervicovaginal mucus flora offer protection from harmful microbes by producing lactic acid, bacteriocins, and other molecules that lower the pH level and increase mucus viscosity. These changes reduce the adherence of harmful bacteria to the epithelial tissue. [ 5 ]


Throughout the menstrual cycle, the cervical mucus undergoes distinct changes. During the follicular phase, increasing levels of estrogen result in greater mucus volume and gradual reduction in thickness. Ovulation triggers significant surges in mucus levels due to high expression of  MUC5B  which creates a watery consistency that aids sperm mobility into the reproductive tract. In the luteal phase, progesterone leads to a decrease in  MUC5B  expression, resulting in the thickening of cervical mucus. Immune factors and antimicrobial peptides vary a different stages of the menstrual cycle. [ 6 ]


Healthy pregnancy results in a dense CMP which protects the uterine cavity from infection. [ 1 ]  Elevated progesterone plasma levels induce cervical mucus to form a more viscous plug called the CMP. [ 7 ]


One of the most common causes of preterm birth is inflammation induced by the changes in vaginal bacterial flora. [ 8 ]   Lactobacillus  plays an important role in maintaining the vaginal PH by producing lactic acids that protects against infections. Lactobacillus bacteria reduction in the vaginal bacterial flora leads other anaerobic bacteria to grow more easily. It also lead to increased cervical mucus IL-8 and increased preterm birth. [ 8 ]   Dysbiosis  occurs when the presence of naturally occurring bacteria such as lactobacilli declines resulting in an increase of harmful bacteria within the vagina. These changes result a CMP that is thin and porous which can leave the uterine compartment susceptible to infection. [ 1 ]


Infections of the placenta and amniotic fluid by bacteria found in the vagina have been closely correlated to preterm labor. [ 7 ]  The CMP of pregnant women is in direct contact with the supracervical region of the  chorioamniotic membranes  which contain  amniotic fluid . This allows direct protection of the fetus. [ 7 ]


Impairment of a CMP may be caused by  cervical effacement , resulting in loss of the CMP. [ 2 ]  The CMP's most important task is to protect reproductive organs against infection by microorganisms coming from the vagina. It does so with a variety of polypeptides that have activity against microorganisms and  immunoglobulins . [ 9 ]  Without protection by the CMP, infection can occur leading to a number of complications. [ 10 ]


A common complication in pregnancy is preterm birth, as mentioned before. Preterm birth is birth prior to 37 weeks of gestation. In individuals with a higher risk for preterm birth, the CMP is found to be more translucent, extensible, and permeable compared to those at low risk for preterm birth. These individuals also may display shorter cervix which can result in increased risk of  intra-amniotic infection . [ 7 ]  The permeability of the CMP is the most important factor as it can allow for a higher risk for the entrance of foreign particles that are harmful. It seems that those at a higher risk for preterm birth develop a less thick and impermeable CMP during the pregnancy, which in turn allows for the entrance of more foreign particles such as bacteria, which is a known cause of preterm birth.


Dysbiosis in the cervicovaginal microbiota has been closely associated with increased HPV infections. Human papillomaviruses are a type of double-stranded DNA viruses categorized within the Papillomaviridae family. HPV infections are primarily transmitted through sexual contact. A healthy vaginal microbiota plays a crucial role in preventing various urogenital infections including sexually transmitted diseases. However, HPV infection occurs when it inhibits the production of cytokines, leading to changes in the microbial interactions within the cervical microenvironment. [ 11 ] [ 12 ]  Lactobacillus bacteria plays an important role in maintaining the PH of the vagina by producing lactic acid. The lactate generated by lactobacilli elevates the thickness of cervical mucus, creating a barrier that entangles viral particles and hinders papillomavirus from reaching basal keratinocytes, which plays an important  role in protection.  When lactobacillus bacterias decline, the vaginal microbiota is dominated by non lactobacillus species. This increases the risk of HPV infections. [ 11 ]


Chadwick sign  is a medical  clinical sign  characterised by the bluish-violet discolouration of the  mucous membranes  of the  vulva ,  vagina  (particularly on the anterior vaginal wall), and the  cervix , resulting from  venous congestion  due to increased  blood flow  as part of the  maternal physiological changes in pregnancy . This clinical sign can be observed during a patient's examination as early as 8 to 12 weeks' gestation, serving as an early sign of  pregnancy , but it is rarely seen before 7 weeks' gestation. [ 1 ]


The discovery of this colour change dates back to approximately 1836 when French doctor Étienne Joseph Jacquemin (1796–1872) first identified it. [ 2 ]  Subsequently,  James Read Chadwick , after presenting a paper before the American Gynecological Society in 1886, and subsequently publishing it the following year, brought attention to this phenomenon. In his paper, Chadwick acknowledged Jacquemin for the initial discovery of the color changes associated with pregnancy. [ 2 ] [ 3 ]


Coffin birth , also known as  postmortem fetal extrusion , [ 1 ] [ 2 ]  is the expulsion of a  nonviable   fetus  through the  vaginal  opening of the decomposing body of a deceased pregnant woman due to increasing pressure from intra-abdominal gases. This kind of postmortem delivery occurs very rarely during the  decomposition  of a body. The practice of  chemical preservation , whereby chemical preservatives and  disinfectant  solutions are pumped into a body to replace natural body fluids (and the  bacteria  that reside therein), have made the occurrence of "coffin birth" so rare that the topic is rarely mentioned in international medical discourse.


Typically during the decomposition of a human body, naturally occurring bacteria in the organs of the abdominal cavity (such as the  stomach  and  intestines ) generate gases as by-products of  metabolism , which causes the body to swell. In some cases, the confined pressure of the gases can squeeze the  uterus  (the womb), even forcing it downward, and it may  turn inside-out  and be forced out of the body through the vaginal opening (a process called  prolapse ). If a fetus is contained within the uterus, it could therefore be expelled from the mother's body through the vaginal opening when the uterus turns inside-out, in a process that, to outward appearances, mimics  childbirth . The main differences lie in the state of the mother and fetus and the mechanism of delivery: in the event of natural, live childbirth, the mother's  contractions  thin and widen the cervix to expel the infant from the womb; in a case of coffin birth, built-up gas pressure within the  putrefied  body of a pregnant woman pushes the dead fetus from the body of the mother.


Cases have been recorded by medical authorities since the 16th century, though some  archaeological  cases provide evidence for its occurrence in many periods of human history. While cases of postmortem fetal expulsion have always been rare, the phenomenon has been recorded under disparate circumstances and is occasionally seen in a modern forensic context when the body of a pregnant woman lies undisturbed and undiscovered for some time following death. There are also cases whereby a fetus may become separated from the body of the pregnant woman about the time of death or during decomposition, though because those cases are not consistent with the processes described here, they are not considered true cases of postmortem fetal extrusion.


The cause of postmortem fetal extrusion is not completely understood, as the event is neither predictable nor replicable under experimental conditions. Evidence has accumulated opportunistically and direct observation is  serendipitous . [ 2 ]  While it is possible that more than one cause can produce the same result, there is an accepted hypothesis, [ 2 ] [ 3 ]  based on established research in the fields of  biochemistry  and forensic  taphonomy , Note a [ 4 ]  and further supported by observational research, that accounts for the taphonomic mechanisms that would result in the most often encountered cases of postmortem extrusion of a non-viable fetus.


Typically, as a dead body  decomposes , body tissues become depleted of oxygen and the body begins to  putrefy ;  anaerobic bacteria  in the gastrointestinal tract proliferate and as a result of increased  metabolic  activity, release gases such as  carbon dioxide ,  methane , and  hydrogen sulfide . [ 5 ] [ 6 ]  These bacteria  secrete   exoenzymes  to  break down  body cells and  proteins  for ingestion which thus weakens organ  tissues . Increasing pressure forces the  diffusion  of excessive gases into the weakened tissues where they enter the  circulatory system  and spread to other parts of the body, causing both torso and limbs to become  bloated . These decompositional processes weaken the structural integrity of organs by separating  necrotizing  tissue layers. [ 6 ]  Bloating usually begins from two to five days after death, depending on external temperature, humidity, and other environmental conditions. [ 7 ]  As the volume of gas increases, the pressure begins to force various body fluids to exude from all natural orifices. [ 8 ]  It is at this point during the decomposition of a pregnant body that  amniotic membranes  become stretched and separated, and intra-abdominal gas pressure may force the  eversion  and  prolapse  of the  uterus , Note b  which would result in the expulsion of the fetus through the vaginal canal. [ 9 ]  It has been observed that the bodies of  multiparous  women Note c  are more likely to spontaneously expel the fetus during decomposition than those who died during their first  pregnancy , because of the more elastic nature of the  cervix . [ 10 ]


Numerous documented cases of postmortem fetal extrusion were described in the medical compendium  Anomalies and Curiosities of Medicine , first published in 1896. [ 3 ]  The earliest presented case occurred in 1551 when a pregnant woman was tried and  hanged  by the courts of the  Spanish Inquisition . Four hours after her death, and while the body still hung by the neck, two dead infants were seen to fall free of the body. This is unusual for the short amount of time elapsed between death and the postmortem delivery. As no information is given regarding other ambient circumstances, it is unclear whether the onset of putrefaction was accelerated, or if other causal factors were at work. [ 4 ]  In the city of  Brussels , in 1633, a woman died in convulsions and three days later a fetus was spontaneously expelled. In  Weissenfels , in 1861, postmortem fetal extrusion was observed sixty hours after the death of a pregnant woman. Other cases are described, though only a few describe the unexpected discovery of fetal remains following exhumation. Most cases occurred before burial; in some of these, the body was in the casket while in other cases the body was still on its deathbed or on a  bier . [ 3 ]


During the late 19th century, modern  embalming  techniques were developed, whereby preservative and disinfectant chemical compounds (such as  formaldehyde ) are pumped into a body, flushing out the body's natural fluids, and with them the bacteria that flourish during putrefaction and generate the gases that comprise the active force behind the expulsion of the fetus. [ 11 ]  However, the phenomenon was still recognized by medical science and in 1904, John Whitridge Williams wrote a textbook on obstetric medicine that included a section on "coffin birth". [ 10 ]  Although the text has remained an important reference in obstetrics, the subject, whether called "coffin birth" or "postmortem fetal extrusion", was excluded by its 13th edition in 1966, [ 12 ]  and was not mentioned in the edition published in 2009. [ 13 ]  The subject was discussed in German medical literature during the 20th century, [ 14 ] [ 15 ] [ 16 ] [ 17 ]  though more detailed case reports in the forensic literature have been published recently. [ 1 ] [ 2 ]


In 2005, the body of a 34-year-old woman, eight months pregnant, was discovered in her apartment in  Hamburg, Germany . [ 2 ]  The body was bloated and discolored, and upon initial examination, it was found that the head of the fetus had made its appearance in the vaginal opening. At  autopsy , medical examiners found that both the head and shoulders of the fetus had emerged, and concluded that it was a case of postmortem fetal extrusion in progress. The woman, who had given birth twice before, had died of a heroin overdose. [ 2 ]  The case was unusual and serendipitous, as it was the first modern case in which medical practitioners were able to document a case of postmortem fetal extrusion in progress. [ 2 ]


In 2008, the body of a 38-year-old woman, seven months pregnant, was discovered in an open field four days after she had disappeared from her residence in  Panama . [ 1 ]  A plastic bag had been left over her head, and she had been gagged; the case was ruled a homicide. The body had suffered from the tropical heat and high humidity, and was bloated and highly discolored. At autopsy, the remains of the fetus were discovered in the woman's undergarments. Although the fetus was in a similar state of decomposition, the  umbilical cord  was intact and still attached to the  placenta  inside the uterus. This was the first forensic case in which it could be concluded that coffin birth had occurred based on the position of the bodies and the clear attachment of the umbilical cord to the un-expelled placenta. [ 1 ]


In 2019, the autopsy reports in the case of the  Watts family homicides  in August 2018 revealed that Shanann Watts (who had been 15 weeks pregnant at the time of her murder) had been found in a shallow grave and that the fetus had been expelled from her body, along with the placenta and umbilical cord. [ 18 ]


Postmortem fetal extrusion can be very difficult to recognize once a body has undergone complete  skeletonization , and  bioarchaeologists  are often very cautious about asserting the presence of this phenomenon. [ 19 ] [ 20 ]  There are numerous cultural reasons why a mother and an infant might be interred together, so the joint presence of neonatal remains and an adult female is not taken as conclusive evidence of postmortem fetal extrusion; [ 19 ] [ 20 ]  however, there have been excavated burials where the position of a set of fetal remains relative to those of an adult female supported this  hypothesis . There are a few general guidelines when an archaeologist is assessing the placement of the fetus and the adult: [ 19 ]


In 1975, it was reported that during the excavation of a medieval cemetery in  Kings Worthy ,  England , fetal remains appeared to lie within the  birth canal  of the skeleton of a young woman, with the fetal cranium external to the pelvic outlet and between the two  femora  (thigh bones) and the fetal leg bones clearly within the  pelvic cavity . [ 22 ]  Other cases of coffin birth at archaeological sites have been described, such as in 1978 at a  Neolithic  site in Germany, [ 24 ]  at a medieval site in  Denmark  in 1982, [ 23 ]  and in 2009 at an  Early Christian period  site at  Fingal ,  Ireland . [ 21 ]  A coffin birth was also described in a 2011 episode of the BBC show  History Cold Case , featuring the Roman era remains of a woman and three neonates discovered near  Baldock ,  Hertfordshire . [ 25 ]  Another was identified in 2006 in a 14th-century Black Death cemetery in  Genoa , Italy. [ 26 ]


Because postmortem fetal extrusion is so rare, and occurs under highly idiosyncratic conditions regarding the individual and the ambient environment, [ 3 ] [ 5 ] [ 10 ] [ 19 ]  this phenomenon has not been studied for possible applications to forensic investigation. Even if the study of postmortem fetal extrusion could lead to improved investigative methods, experimental research would be highly problematic. At present,  forensic scientists  have at their disposal an array of established techniques and procedures for a death investigation at the stages of decomposition when postmortem fetal extrusion typically occurs. [ 9 ]


In archaeology, the study of mortuary context, that is, the interpretation of the postmortem treatment of the dead, whether an individual or as pertains to patterns within a group, has led to the development of hypotheses on social status and/or hierarchy regarding many cultures, ancient and extant. [ 23 ] [ 27 ] [ 28 ] [ 29 ] [ 30 ]  In addition, the determination of whether or not delivery actually occurred before death has a bearing on analyses of the mother's population, as the concentration of  trace elements  differ markedly between the skeletons of prepartum adult women (before giving birth) and women who are  lactating ; the identification of coffin birth would lead to more accurate analyses of the number of lactating women in a population or the rate of maternal mortality. [ 31 ]  It is therefore necessary for investigators to be able to recognize postmortem fetal extrusion when encountered in an excavated burial. [ 20 ] [ 32 ]


There are also many cases where the remains of the fetus are found separate from the body of the mother, but expulsion was not through the birth canal, and separation of the two bodies may have been influenced by external environmental factors. The process of separation is so unusual that a specific term for the phenomenon may not have been proposed to the scientific community. These cases may have comparable results, but they are not cases of postmortem fetal extrusion.


In April 2003, the body of  Laci Peterson  washed up on a shore near  San Francisco Bay ; she had been pregnant when she disappeared four months earlier, and the fetus she had been carrying was discovered on a separate beach. When questioned by the media, medical authorities initially speculated that a "coffin birth" might have occurred. [ 33 ]  However, at autopsy the cervix was found to be in a  prepartum condition . Medical examiners later concluded that while Peterson's body was in the bay, the skin over the abdominal cavity had ruptured due to natural decompositional processes. Seawater entered the abdominal cavity and washed out most of the internal organs, along with the fetus. [ 34 ]


In 2007, a 23-year-old woman in India, over eight months pregnant, hanged herself after  contractions  had begun. [ 35 ]  A viable infant was spontaneously delivered unassisted from the woman's body, which was suspended by the neck. The healthy infant was found on the floor, still tethered to the body of the mother by the umbilical cord. The primary cause of the delivery was the otherwise normal contractions, which had begun before death, and was therefore not related to processes of decomposition. [ 6 ] [ 35 ]  While this is not postmortem fetal extrusion, it may be referred to as a case of  postmortem delivery , a term which is applied to a broad range of techniques and phenomena with a resultant delivery of a live infant. [ 36 ]


In 2008, in Germany, a 23-year-old woman in her third  trimester  was involved in a motor vehicle accident and died; the non-viable fetus was found between her feet. [ 37 ]  The vehicle caught fire following initial impact. The woman died of blunt trauma, and her body burned in the car. Investigators came to the conclusion that the extreme heat of the fire burned away  epidermal  and  subcutaneous tissue  around the abdominal cavity, after which the  anterior aspect  of the uterus ruptured, causing the fetus to spill out of the uterine cavity and land on the floor between the woman's feet. The umbilical cord was still intact and connected the fetus to the placenta through the ruptured wall of the uterus. Unlike the woman, who suffered  fourth-degree  burns over her entire body, the body of the fetus was relatively undamaged. [ 37 ]  Because the primary cause of separation from the mother's body was thermally induced traumatic rupture of the abdominal and uterine cavities; traumatic separation was not related to normal decompositional processes; and expulsion of the fetus did not involve passage through the birth canal, this is not considered a case of postmortem fetal extrusion. [ 37 ]


Whales can be subject to postmortem fetal extrusion. Many species float when dead, due to the gases of putrefaction.  Drift whales  that wash up on shore, and the carcasses of  hunted whales , if not  flensed  (stripped of  blubber ) and processed in a timely manner, pose a risk.  Tim Flannery  wrote that "A rotting whale could fill with gas to bursting, ejecting a fetus the size of a motor vehicle with sufficient force to kill a man." [ 38 ]


Congenital pulmonary airway malformation  ( CPAM ), formerly known as  congenital cystic adenomatoid malformation  ( CCAM ), is a  congenital disorder  of the lung similar to  bronchopulmonary sequestration . In CPAM, usually an entire lobe of lung is replaced by a non-working cystic piece of abnormal lung tissue. This abnormal tissue will never function as normal lung tissue. The underlying cause for CPAM is unknown. It occurs in approximately 1 in every 30,000 pregnancies. [ 1 ]


In most cases the outcome of a fetus with CPAM is very good. In rare cases, the cystic mass grows so large as to limit the growth of the surrounding lung and cause pressure against the heart. In these situations, the CPAM can be life-threatening for the fetus. CPAM can be separated into five types, based on clinical and pathologic features. [ 2 ]  CPAM type 1 is the most common, with large  cysts  and a good prognosis.  CPAM type 2 (with medium-sized cysts) often has a poor prognosis, owing to its frequent association with other significant anomalies. Other types are rare. [ 3 ]


Three quarters of affected patients are asymptomatic. However, 25% develop  cyanosis ,  pneumothorax , and show signs of increased breathing difficulty (tachypnoea and intercostal retractions). At examination, they may show hyper-resonance at percussion, diminished vesicular murmur and an asymmetrical thorax. [ citation needed ]


The cause of CPAM is unknown.


CPAMs are often identified during routine prenatal  ultrasonography . Identifying characteristics on the sonogram include: an echogenic (bright) mass appearing in the chest of the fetus, displacement of the heart from its normal position, a flat or everted (pushed downward) diaphragm, or the absence of visible lung tissue. [ citation needed ]


CPAMs are classified into three different types based largely on their gross appearance.  Type I has a large (>2 cm) multiloculated cysts.  Type II has smaller uniform cysts.  Type III is not grossly cystic, referred to as the "adenomatoid" type.  Microscopically, the lesions are not true cysts, but communicate with the surrounding parenchyma. Some lesions have an abnormal connection to a blood vessel from an aorta and are referred to as "hybrid lesions."


The earliest point at which a CPAM can be detected is by  prenatal   ultrasound . The classic description is of an  echogenic  lung mass that gradually disappears over subsequent ultrasounds. The disappearance is due to the malformation becoming filled with fluid over the course of the gestation, allowing the ultrasound waves to penetrate it more easily and rendering it invisible on sonographic imaging. When a CPAM is rapidly growing, either solid or with a dominant cyst, they have a higher incidence of developing venous outflow  obstruction ,  cardiac failure  and ultimately  hydrops fetalis . If  hydrops  is not present, the fetus has a 95% chance of survival. When hydrops is present, risk of fetal demise is much greater without  in utero   surgery  to correct the pathophysiology. The greatest period of growth is during the end of the second  trimester , between 20 and 26 weeks. [ citation needed ]


A measure of mass volume divided by head circumference, termed cystic adenomatoid malformation volume ratio (CVR) has been developed to predict the risk of  hydrops . The lung mass volume is determined using the formula (length × width × anteroposterior diameter ÷ 2), divided by head circumference. With a CVR greater than 1.6 being considered high risk. Fetuses with a CVR less than 1.6 and without a dominant cyst have less than a 3% risk of hydrops. After delivery, if the patient is symptomatic, resection is mandated. If the infant is asymptomatic, the need for resection is a subject of debate, though it is usually recommended. Development of recurrent infections,  rhabdomyosarcoma ,  adenocarcinomas  in situ  within the lung malformation have been reported. [ 4 ]


In most cases, a fetus with CPAM is closely monitored during pregnancy and the CPAM is removed via surgery after birth. [ 5 ]  Most babies with a CPAM are born without complication and are monitored during the first few months.  Many patients have surgery, typically before their first birthday, because of the risk of recurrent lung infections associated with CPAMs.  Some pediatric surgeons can safely remove these lesions using very tiny incisions using minimally invasive surgical techniques ( thoracoscopy ). However, some CPAM patients live a full life without any complication or incident.  It is hypothesized that there are thousands of people living with an undetected CPAM. Through ultrasound testing employed in recent years, many more patients are aware that they live with this condition. Rarely, long standing CPAMs have been reported to become cancerous. [ citation needed ]


Very large cystic masses might pose a danger during birth because of the airway compression. In this situation, a special surgical type of delivery called the  EXIT procedure  may be used.


In rare extreme cases, where fetus's heart is in danger,  fetal surgery  can be performed to remove the CPAM. If non-immune  hydrops fetalis  develop, there is a near universal mortality of the fetus without intervention. Fetal surgery can improve the chances of survival to 50-60%. Recently, several studies found that a single course of prenatal steroids (betamethasone) may increase survival in hydropic fetuses with microcystic CPAMs to 75-100%. [ 6 ] [ 7 ]  These studies indicate that large microcystic lesions may be treated prenatally without surgical intervention. Large macrocyst lesions may require in utero placement of a Harrison thoracoamniotic shunt.


Thoracentesis, the draining of large, fluid-filled cysts, involves inserting a needle through the womb into the lesion and draining the fluid. [ 8 ]


A 2023 review found that the overall prognosis for congenital pulmonary airway malformation, when diagnosed prenatally, was excellent. However, if  fetal hydrops  was present the survival rate dropped. [ 9 ]  If hydrops had not developed by the 26th week of pregnancy then risk reduced. [ 10 ]


Infection and pleuropulmonary blastoma (PPB) are possible later complications. [ 11 ]


Crown-rump length  ( CRL ) is the measurement of the length of human  embryos  and  fetuses  from the top of the head (crown) to the bottom of the buttocks (rump). It is typically determined from  ultrasound imagery  and can be used to estimate  gestational age .


The embryo and fetus float in the  amniotic fluid  inside the  uterus  of the mother usually in a curved posture resembling the letter  C . The measurement can actually vary slightly if the fetus is temporarily stretching (straightening) its body. The measurement needs to be in the natural state with an unstretched body which is actually  C  shaped. The measurement of CRL is useful in determining the gestational age (menstrual age starting from the first day of the last menstrual period) and thus the expected date of delivery (EDD). Different human fetuses grow at different rates and thus the gestational age is an approximation. Recent evidence has indicated that CRL growth (and thus the approximation of gestational age) may be influenced by maternal factors such as age,  smoking , and folic acid intake. Early in  pregnancy  gestational age 8 weeks, it is accurate within about +/- 5 days but later in pregnancy due to different growth rates, the accuracy is less. In that situation, other parameters can be used in addition to CRL. The length of the  umbilical cord  is approximately equal to the CRL throughout pregnancy.


Gestational age is not the same as fertilization age. It takes about 14 days from the first day of the last menstrual period for  conception  to take place and thus for the  conceptus  to form. The age from this point in time (conception) is called the fertilization age and is thus 2 weeks shorter than the gestational age. Thus a 6-week gestational age would be a 4-week fertilization age. Some authorities however casually interchange these terms  [ citation needed ]  and the reader is advised to be cautious. An average gestational period (duration of pregnancy from the first day of the last menstrual period up to delivery) is 280 days. On average, this is 9 months and 6 days.


A commonly used estimate of gestational age in weeks is (as described by Verburg et al. [ 2 ] ):


G

 A

 w
 e
 e
 k
 s

 =
 C
 R

 L

 0.2313

 ⋅

 e

 1.4653
 +
 0.001737
 ⋅
 C
 R
 L

 {\displaystyle GA_{weeks}=CRL^{0.2313}\cdot e^{1.4653+0.001737\cdot CRL}}


Gestational age estimation in days is carried out according to the equations:


G

 A

 d
 a
 y
 s

 =
 40.9
 +
 3.24585
 ⋅
 C
 R

 L

 0.5

 +
 0.348956
 ⋅
 C
 R
 L

 {\displaystyle GA_{days}=40.9+3.24585\cdot CRL^{0.5}+0.348956\cdot CRL}

  ; and SD of GA = 2.39102 + (0.0193474 × CRL).


The  decidua  is the modified  mucosal lining  of the  uterus  (that is, modified  endometrium ) that forms every month, in preparation for  pregnancy . It is shed off each month when there is no fertilized egg to support. [ 1 ]  The decidua is under the influence of  progesterone . Endometrial cells become highly characteristic. The decidua forms the maternal part of the  placenta  and remains for the duration of the pregnancy.  After birth the decidua is shed together with the placenta. [ 1 ]


The part of the decidua that interacts with the  trophoblast  is the  decidua basalis  (also called  decidua placentalis ), while the  decidua capsularis  grows over the  embryo  on the luminal side, enclosing it into the endometrium. The remainder of the decidua is termed the  decidua parietalis  or  decidua vera , and it will fuse with the decidua capsularis by the fourth month of gestation.


Three morphologically distinct layers of the decidua basalis can then be described:


Within the decidua, occasional fibrinoid deposits form where the syncytiotrophoblast is damaged. The region of fibrinoid deposition where trophoblasts meet the compact portion of the decidua basalis is called  Rohr's layer , while the fibrinoid deposits that occur between the compact and spongy layer of the decidua basalis is termed  Nitabuch's layer  (for  Raissa Nitabuch ). This layer is absent in  placenta accreta . [ 2 ]


The decidua has a  histologically -distinct appearance, displaying large polygonal  decidual cells  in the stroma. These are enlarged endometrial stromal cells, which resemble  epithelium  (and are referred to as "epithelioid").


Decidualization  includes the process of differentiation of the spindle-shape stromal fibroblasts into the plump secretory decidual cells, which create a pericellular extracellular matrix rich in  fibronectin  and  laminin  (similar to epithelial cells).


Vascularity, as well as vascular permeability, is enhanced in the decidualizing endometrium.


Its  leukocyte  population is distinct, with the presence of large endometrial granular leukocytes being predominant, while polynuclear leukocytes and  B cells  are scant.


The large granular lymphocytes ( CD56  bright) are called  uterine natural killer cells | (uNK cells).


After  ovulation , in  placental mammals , the endometrial lining becomes hypertrophic and vascular under the influence of the  sex hormones ,  estrogen  and  progesterone .


In animals exhibiting  hemochorial placentation , the endometrium undergoes  decidualization  following  implantation . If implantation does not occur, the secretory lining will be absorbed ( estrous cycle ) or shed ( menstrual cycle ).


The decidua is shed with the placenta during  birth .


As the maternal interface to the embryo the decidua participates in the exchanges of nutrition, gas, and waste with the gestation. It also protects the pregnancy from the maternal  immune system . Further, the decidua has to allow a very controlled invasion of the trophoblast.


In invasive placental disorders like  placenta accreta  decidualization have been consistently found to be deficient.


The decidua secretes  hormones ,  growth factors , and  cytokines . It has receptors for  estrogen ,  progesterone ,  growth hormone , and others.


Among its products are hormones commonly associated with other organs such as  cortisol ,  CRF ,  GnRH ,  prolactin , and  relaxin . Decidual prolactin is not under  dopaminergic  control.


Insulin-like growth factor-binding protein 1  (IGFBP1) also called placental protein 12, and  PAEP  (glycodelin) appear to be specific products of the secretory and decidual lining.


Other factors released include  interleukin-15  and  vascular endothelial growth factor  (VEGF). A reasonable understanding of the role and interplay of these hormones and factors has not been evolved.


A long-lasting  infection  of the decidua,  chronic deciduitis , is associated with  pre-term labour . [ 4 ]


The word comes from  Latin    deciduus  'falling off / shedding'.


The medical post-nominal suffix  DObst RCOG  is awarded to  obstetricians  and  gynaecologists  who have gained the Diploma of the  Royal College of Obstetricians and Gynaecologists . The Diploma is aimed at  doctors , and especially  general practitioners , who wish to certificate their knowledge and interest in Women's Health. [ 1 ]


A  Doppler fetal monitor , informally known as  sonicaid  ( generic trademark ), is a hand-held  ultrasound  transducer used to detect the  fetal heartbeat  for  prenatal care .  It uses the  Doppler effect  to provide an audible simulation of the heart beat.  Some models also display the  heart rate  in beats per minute (BPM). Use of this monitor is sometimes known as  Doppler  auscultation . The Doppler fetal monitor is commonly referred to simply as a  Doppler  or  fetal Doppler . It may be classified as a form of  Doppler ultrasonography  (although usually not technically  -graphy  but rather sound-generating).


Doppler fetal monitors provide information about the fetus similar to that provided by a  fetal stethoscope . One advantage of the Doppler fetal monitor over a (purely acoustic) fetal stethoscope is the electronic audio output, which allows people other than the user to hear the heartbeat. One disadvantage is the greater complexity and cost and the lower reliability of an electronic device. [ citation needed ]


The device was invented in 1958 by Dr. Edward H. Hon, [ 1 ]  Originally intended for use by health care professionals, this device is becoming popular for personal use.


Dopplers for home or hospital use differ in the following ways:


A major advantage of being able to record and share the recording is that it can be emailed to a healthcare professional to be checked if there are any concerns about whether or not it is the fetus's heart rate and whether or not is normal.  Typically, they work from about 12 weeks. [ 2 ]


In response to increasing home usage of clinical fetal doppler systems, the FDA issued a formal statement recommending against at-home use. [ 3 ]  Fetal dopplers using 2-3MHz ultrasound are prescription devices designed and developed for use by licensed and trained health care professionals. System misuse (duration, angulation) and systems operating outside of intended range can produce thermal and non-thermal effects on fetal tissue, including the possibility for over-heating fetal tissue and introducing mechanical stress on the fetus due to cavitation, radiation force, and acoustic streaming. [ 4 ] [ 5 ]


Women should speak to their doctor or healthcare professional before starting or stopping any medications while pregnant. [ 1 ]  Drugs taken in pregnancy including over-the counter-medications, prescription medications, nutritional supplements, recreational drugs, and illicit drugs may cause harm to the mother or the unborn child. Non-essential drugs and medications should be avoided while pregnant. Tobacco, alcohol, marijuana, and illicit drug use while pregnant may be dangerous for the unborn baby and may lead to severe health problems and/or birth defects. [ 2 ]  Even small amounts of alcohol, tobacco, and marijuana have not been proven to be safe when taken while pregnant. [ 3 ]    In some cases, for example, if the mother has epilepsy or diabetes, the risk of stopping a medication may be worse than risks associated with taking the medication while pregnant. The mother's healthcare professional will help make these decisions about the safest way to protect the health of both the mother and unborn child. [ 4 ]  In addition to medications and substances, some dietary supplements are important for a healthy pregnancy, however, others may cause harm to the unborn child. [ 5 ]


The  Food and Drug Administration  (FDA) in the United States reports that there are six million pregnancies with at least 50% of the women taking at least one medication. [ 6 ]  In addition a reported 5–10% of women of childbearing age use  alcohol  or other  addictive substances . [ 7 ]  Of those who bear children, recreational drug use can have serious consequences to the health of not only the mother, but also the fetus as many medications can cross the placenta and reach the fetus. Some of the consequences on the babies include physical and mental abnormalities, higher risk of stillbirth,  neonatal abstinence syndrome  (NAS),  sudden infant death syndrome  (SIDS), low birthweight, and others. [ 8 ]


Medications during pregnancy must be carefully considered. Many types of drugs, medications, and even nutritional supplements can affect fetal development or cause complications. For over-the-counter and prescription medications, healthcare professionals can help weigh the potential risks and benefits of taking medication while pregnant and if it is needed. Some medications may be necessary for the health and well being of both the mother and the unborn child, and some medications may come with a risk of harm to the unborn baby, but in some instances the benefits may outweigh the risks to the baby or mother.


Women who have  diabetes mellitus  may still need intensive therapy with insulin to prevent complications to the mother and baby.  Gestational diabetes  is a form of diabetes that is first diagnosed during pregnancy and can accordingly cause high blood sugar that affects the woman and the baby. [ 9 ]  In 10 - 20% of women whose diet and exercise are not adequate enough to control blood sugar,  insulin  injections may be required to lower blood sugar levels. [ 9 ]  Medications that can be used in diabetes during pregnancy include insulin, glyburide and metformin. [ 10 ]


Pregnant women who use prescription medications containing  opioids  while pregnant may cause serious harm to the mother or unborn child. [ 11 ]  For some people, the risk of stopping a medication such as prescription opioids may be more serious than the risk of taking a medication. [ 11 ]


Short-term use of  acetaminophen  as directed is one of the only medications recommended for treating pain and fever in women who are pregnant. [ 12 ]  There is no established association with teratogenicity or elevated occurrence of birth defects and the usage of acetaminophen at any point during a pregnancy. [ 12 ]  There is potential for fetal liver toxicity in cases of maternal overdose, where the mother consumes more than the recommended daily dose. [ 13 ]


Ibuprofen and naproxen have not frequently been studied during pregnancy, but recent studies do not show increased risk of spontaneous abortion within the first six weeks of pregnancy. [ 14 ] [ 12 ]  However, all NSAIDs showed association with structural cardiac defects with usage during the early weeks of pregnancy. When ibuprofen and naproxen are used within the third trimester, there is a significant increase in the risk of premature closure of the ductus arteriosus with primary pulmonary hypertension in the newborn. [ 12 ]  Between the lack of studies of the effect of ibuprofen and naproxen on pregnancy, it is recommended that pregnant women avoid these medications or use them sparingly per physician recommendations. [ 14 ]


Usage of  aspirin  for pain relief during pregnancy is not recommended. Aspirin use during pregnancy has not demonstrated an increased risk of spontaneous abortion within the early weeks of pregnancy. However, its usage during  organogenesis  and the third trimester can lead to elevated risk of  intrauterine growth retardation  and  maternal hemorrhage . [ 15 ]


While aspirin should be avoided for use pain relief, low dose aspirin is used for prevention of preeclampsia and  fetal growth restriction  (FGR) in patients with previous risk factors (e.g. previous preeclampsia, multiple pregnancies, hypertension and diabetes). [ 16 ]


For more information, see the below section on  Recreational drugs


Any medications containing opioids may be dangerous for the unborn baby and should not be taken while pregnant. [ 11 ]


Many commonly prescribed  anticonvulsant  medications are associated with an increased risk of birth defects such as neural tube defects, however, most women with epilepsy deliver healthy babies and have a healthy pregnancy. [ 17 ]  Women who have epilepsy often still require treatment to control or prevent seizures and therefore require very early advice (ideally before conceiving the child) from their doctor to determine the safest way to protect both the mother and unborn child. [ 17 ]


Valproic acid  and its derivatives such as  sodium valproate  and  divalproex sodium , commonly used to prevent seizures and treat mood disorders, increase the risk of  congenital malformations  (birth defects) including  neural tube defects  if taken during pregnancy. [ 18 ]  There is evidence that an increased dose or increased exposure  in utero  is associated with an increased risk of lower scores on neurodevelopmental tests. [ 19 ]  Valproic acid use during pregnancy increases the risk of neural tube defects by approximately 20-fold. [ 18 ]  Evidence is conflicting for  carbamazepine  regarding any increased risk of  congenital physical anomalies  or  neurodevelopmental disorders  by intrauterine exposure. [ 19 ]  Similarly, children exposed to  lamotrigine  or  phenytoin  in the womb do not seem to differ in their skills compared to those who were exposed to carbamazepine. [ 19 ]


Heartburn is a common symptom of late term pregnancy during which up to 80% of pregnant women have experienced it by the end of their third trimester. [ 12 ]  Heartburn often indicates the development of  gastro-esophageal reflux disease  (GERD), where the lower esophageal sphincter relaxes due to elevated progesterone levels causing increased frequency and severity of gastric reflux or heartburn. If heartburn appears after 20 weeks of gestational age or is severe and persistent, this can indicate other conditions including  HELLP syndrome  and  preeclampsia . [ 20 ]


Common antacids include aluminum hydroxide/magnesium hydroxide (Maalox) and calcium carbonate (Tums). Histamine H2 blockers and proton pump inhibitors, such as famotidine (Pepcid) and omeprazole (Prilosec), respectively, can also be used to help relieve heartburn, with no known  teratogenic  effects or congenital malformations. [ 12 ]  Aluminum hydroxide/magnesium hydroxide and calcium carbonate, when consumed, do not cross the placenta and are regarded as safe pharmacological options to treat heartburn, since there are no significant association with maldevelopment or injury to fetus. [ 14 ]


Ginger and acupressure are common non-pharmacological options used to treat nausea and vomiting as alternatives to antacids, histamine H2 blockers, and proton pump inhibitors. [ 21 ]  Lifestyle modifications are often recommended as well. Recommended modifications can include avoiding fatty food, reducing size and frequency of meals, and reducing caffeine intake. [ 22 ]