Uterine enlargement beyond 20 weeks' size can compress the inferior vena cava, which can markedly decrease the return of blood into the heart or preload. As a result, healthy pregnancy patients in a supine position or prolonged standing can experience symptoms of hypotension. [ 23 ]


During pregnancy the  plasma  volume increases by 40-50% and the red blood cell volume increases only by 20–30%. [ 22 ]  These changes occur mostly in the second trimester and prior to 32 weeks gestation. [ 24 ]  Due to dilution, the net result is a decrease in  hematocrit  or hemoglobin, which are measures of red blood cell concentration.  Erythropoietin , which stimulates red blood cell production, increases throughout pregnancy and reaches approximately 150 percent of their pregnancy levels at term. [ 24 ]  The slight drop in hematocrit or hemoglobin is most pronounced at the end of the second trimester and slowly improves when reaching term. [ 24 ]


The effect of pregnancy on platelet count is unclear, with some studies demonstrating a mild decline in platelet count and other studies that show no effect. [ 24 ]  The white blood cell count increases with occasional appearance of myelocytes or metamyelocytes in the blood. [ 24 ]  During labor, there is a rise in leukocyte count.


A pregnant woman will also become  hypercoagulable , leading to increased risk for developing blood clots and embolisms, such as  deep vein thrombosis  and  pulmonary embolism . Women are 4-5 times more likely to develop a clot during pregnancy and in the postpartum period than when they are not pregnant. [ 25 ]  Hypercoagulability in pregnancy likely evolved to protect women from hemorrhage at the time of miscarriage or childbirth. In developing countries, the leading cause of maternal death is still hemorrhage. [ 25 ]  In the United States 2011-2013, hemorrhage made up of 11.4% and pulmonary embolisms made up of 9.2% of all pregnancy-related deaths. [ 26 ]


The increased risk of clots can be attributed to several things. Plasma levels of pro-coagulantion factors increased markedly in pregnancy, including:  von Willebrand Factor ,  fibrinogen ,  factor VII ,  factor VIII , and  factor X . [ 24 ]  Both the production of prostacyclin (an inhibitor of platelet aggregation) and thromboxane (an inducer of platelet aggregation and a vasoconstrictor) are increased, but overall there is an increase in platelet reactivity which can lead to a predisposition to clots. [ 27 ]  There is also increased blood stasis due to the compression of the vena cava by the enlargening uterus. [ 28 ]  Many factors have been shown to increase the risk of clots in pregnancy, including baseline thrombophilia, cesarean section, preeclampsia, etc. [ 25 ]  Clots usually develop in the left leg or the left iliac/ femoral venous system. [ 29 ]  Recently, there have been several case reports of May-Thurner Syndrome in pregnancy, where the right common iliac artery compresses the below left common iliac vein. [ 30 ]


Edema , or swelling, of the feet is common during pregnancy, partly because the enlarging uterus compresses veins and lymphatic drainage from the legs.


During pregnancy, both  protein metabolism  and  carbohydrate metabolism  are affected. One  kilogram  of extra  protein  is deposited, with half going to the  fetus  and  placenta , and another half going to  uterine  contractile proteins,  breast glandular  tissue, plasma protein, and  haemoglobin .


An increased requirement for nutrients is given by fetal growth and fat deposition. Changes are caused by steroid hormones, lactogen, and cortisol.


Maternal insulin resistance can lead to  gestational diabetes . Increased liver metabolism is also seen, with increased gluconeogenesis to increase maternal glucose levels. [ citation needed ]


Some degree of weight gain is expected during pregnancy. The enlarging uterus, growing fetus,  placenta ,  amniotic fluid , normal increase in body fat, and increase in water retention all contribute weight gain during pregnancy.  The amount of weight gain can vary from 5 pounds (2.3 kg) to over 100 pounds (45 kg). In the United States, the range of weight gain that doctors generally recommend is 25 pounds (11 kg) to 35 pounds (16 kg), less if the woman is overweight, more (up to 40 pounds (18 kg)) if the woman is underweight. [ citation needed ]


Nutritionally, pregnant women require a caloric increase of 350 kcal/day and an increase in protein to 70 or 75 g/day. [ citation needed ]  There is also an increased  folate  requirement from 0.4 to 0.8 mg/day (important in preventing  neural tube defects ). On average, a weight gain of 20 to 30 lb (9.1 to 13.6 kg) is experienced. [ citation needed ]


All patients are advised to take  prenatal vitamins  to compensate for the increased nutritional requirements. Choline supplementation of research mammals supports mental development that lasts throughout life. [ 32 ]


Progesterone causes many changes to the genitourinary system. A pregnant woman may experience an increase in the size of the kidneys and ureter due to the increase blood volume and vasculature. Later in pregnancy, the woman might develop physiological hydronephrosis and hydroureter, which are normal. [ 33 ]  Progesterone causes vasodilatation and increased blood flow to the kidneys, and as a result  glomerular filtration rate  (GFR) commonly increases by 50%, returning to normal around 20 weeks  postpartum . [ 22 ]  The increased GFR increases the excretion of protein, albumin, and glucose. The increased GFR leads to increased urinary output, which the woman may experience as increased urinary frequency. Progesterone also causes decreased motility of the ureters, which can lead to stasis of the urine and hence an increased risk of urinary tract infection. [ 6 ]


Pregnancy alters the  vaginal microbiota  with a reduction in species/genus diversity. [ 34 ]
Physiological hydronephrosis may appear from six weeks. [ 35 ]


Changes in the gastrointestinal (GI) system during pregnancy are caused by the enlarging uterus and hormonal changes of pregnancy. Anatomically, the intestine and stomach are pushed up from their original positions by the enlarging uterus. While there aren't any intrinsic changes in the sizes of the GI organs, the portal vein increases in size due to the hyperdynamic state of pregnancy. Elevated levels of  progesterone  and  estrogen  mediate most of the functional changes of the GI system during pregnancy. Progesterone causes smooth muscle relaxation which slows down GI motility and decreases  lower esophageal sphincter  (LES) tone. The resulting increase in intragastric pressure combined with lower LES tone leads to the gastroesophageal reflux commonly experienced during pregnancy. [ 36 ]


The increased occurrence of gallstones during pregnancy is due to inhibition of gallbladder contraction (as result of increased smooth muscle relaxation mediated by progesterone) and reduced biliary transportation of bile (mediated by estrogen) which results in  cholestasis of pregnancy . [ 36 ]


Nausea and vomiting of pregnancy, commonly known as  morning sickness , is one of the most common GI symptoms of pregnancy. It begins between the 4 and 8 weeks of pregnancy and usually subsides by 14 to 16 weeks. The exact cause of nausea is not fully understood but it correlates with the rise in the levels of  human chorionic gonadotropin ,  progesterone , and the resulting relaxation of smooth muscle of the stomach.  Hyperemesis gravidarum , which is a severe form of nausea and vomiting of pregnancy can lead to nutritional deficiencies, weight loss, electrolytes imbalance and is one of the leading causes of hospitalization in the first trimester of pregnancy. [ 36 ]


Constipation  is another GI symptom that is commonly encountered during pregnancy. It is associated with the narrowing of the colon as it gets pushed by the growing uterus found adjacent it leading to mechanical blockade. Reduced motility in the entire GI system as well as increased absorption of water during pregnancy are thought to be contributing factors. [ 36 ]


Dietary cravings and dietary as well as olfactory avoidance of certain types of food are common in pregnancy. Although the exact mechanisms of these symptoms are not fully explained, it is thought that dietary cravings may arise from the thought that certain foods might help relieve nausea.   Pica , which is the intense craving for unusual materials such as clay and ice has also been reported in pregnancy. [ 36 ]


Hemorrhoids and gingival disease are two common pregnancy associated physical findings involving the gastrointestinal system. Hemorrhoids arise as a result of constipation and venous congestion that are common in pregnancy. Gingival disease is thought to be related to gum softening and edema (swelling from fluid collection) that is mostly observed in pregnancy.  The mechanism and reason for the gingival changes are poorly understood. [ 36 ]


The  fetus  inside a pregnant woman may be viewed as an unusually successful  allograft , since it genetically differs from the woman. [ 37 ]  In the same way, many cases of  spontaneous abortion  may be described in the same way as maternal  transplant rejection . [ 37 ]


Neuromechanical adaptations to pregnancy refers to the change in gait, postural parameters, as well as  sensory feedback , due to the numerous anatomical, physiological, and hormonal changes women experience during  pregnancy . Such changes increase their risk for  musculoskeletal  disorders and fall injuries. Musculoskeletal disorders include lower-back pain, leg cramps, and  hip pain . Pregnant women fall at a similar rate (27%) to women over age of 70 years (28%). Most of the falls (64%) occur during the second trimester.  Additionally, two-thirds of falls are associated with walking on slippery floors, rushing, or carrying an object. [ 38 ]   The root causes for these falls are not well known. However, some factors that may contribute to these injuries include deviations from normal  posture ,  balance , and  gait .


The body's posture changes as the pregnancy progresses. The pelvis tilts and the back arches to help keep balance. Poor posture occurs naturally from the stretching of the woman's abdominal muscles as the fetus grows. These muscles are less able to contract and keep the lower back in proper alignment. The pregnant woman has a different pattern of gait. The step lengthens as the pregnancy progresses, due to weight gain and changes in posture. On average, a woman's foot can grow by a half size or more during pregnancy. In addition, the increased body weight of pregnancy, fluid retention, and weight gain lowers the arches of the foot, further adding to the foot's length and width. The influences of increased hormones such as  estrogen  and  relaxin  initiate the remodeling of soft tissues, cartilage and ligaments. Certain skeletal joints such as the  pubic symphysis  and  sacroiliac  widen or have increased laxity. [ citation needed ]


The addition of mass, particularly around the  torso , naturally changes a pregnant mother's  center of mass  (COM). The change in COM requires pregnant mothers to adjust their bodies to maintain  balance .


To positionally compensate the additional load due to the pregnancy, pregnant mothers often extend their lower backs. As the fetal load increases, women tend to arch their lower backs, specifically in the lumbar region of their vertebral column to maintain postural stability and balance. The arching of the lumbar region is known as lumbar  lordosis , which recovers the center of mass into a stable position by reducing hip  torque . According to a study conducted by Whitcome, et al., lumbar lordosis can increase from an angle of 32 degrees at 0%  fetal  mass (i.e. non-pregnant women or very early in pregnancy) to 50 degrees at 100% fetal mass (very late in pregnancy). Postpartum, the angle of the lordosis declines and can reach the angle prior to pregnancy. Unfortunately, while lumbar lordosis reduces hip torque, it also exacerbates spinal shearing load, [ 39 ]  which may be the cause for the common lower back pain experienced by pregnant women. [ 40 ]


Given the demands of fetal loading during pregnancy and the importance of producing  offspring  to the  fitness  of  human beings ,  natural selection  may have had a role in selecting a unique  anatomy  for the  lumbar region  in females. There are sex differences in the lumbar vertebral column of human males and females, which ultimately helps mitigate some of the discomfort due to the fetal load in females. There are 5 vertebrae in the lumbar region for both males and females. However, the 3 lower vertebrae of a female's lumbar region are dorsally wedged while for males, only the lower 2 of the lumbar region are dorsally wedged. When a female arches her lower back, such as during fetal loading, having an extra dorsally wedged vertebra lessens the shearing force. This lumbar  sexual dimorphism  in humans suggests high natural selection pressures have been acting to improve maternal performance in posture and locomotion during pregnancy. [ 39 ]


If natural selection has acted on the lumbar region of  Homo sapiens  to create this sexual dimorphism, then this sort of trait should also be apparent in the genus  Australopithecus ,  hominins  that have been known to be habitually  bipedal  for at least 2 million years after the earliest bipedal hominins. Currently there are 2 nearly complete australopith lumbar segments; one has three dorsally wedged vertebrae in the lumbar region while the other has two. An explanation for these findings is that the first one is a female, while the latter is a male. This sort of evidence supports the notion that natural selection has played a dimorphic role in designing the anatomy of the vertebral lumbar region. [ 39 ]


The weight added during the progression of pregnancy also affects the ability to maintain balance.


Pregnant women have a decreased  perception  of balance during quiet standing, which is confirmed by an increase in anterior-posterior (front to back) sway. [ 41 ]  This relationship heightens as pregnancy progresses and significantly decreases  postpartum . To compensate for the decrease in balance stability (both actual and perceived), stance width increases to maintain postural stability.


Under dynamic  postural stability , which can be defined as the response to anterior (front) and posterior (back) translation perturbations, the effects of pregnancy are different.  Initial sway ,  total sway , and  sway velocity  (see figure for description of variables) are significantly less during the third trimester than during the second trimester and when compared to non-pregnant women. These  biomechanical  characteristics are possible reasons why falls are more prevalent during the second trimester during pregnancy.


Additionally, the time it takes for pregnant women (any stage of pregnancy) to react to a translational disturbance is not significantly different than that of non-pregnant women. [ 42 ]  This alludes to some sort of stability mechanism that allow pregnant women to compensate for the changes they experience during pregnancy.


Gait  in pregnant women often appear as a “waddle” – a forward gait that includes a  lateral component . However, research has shown that the forward gait alone remains unchanged during pregnancy. It has been found that gait parameters such as gait  kinematics , ( velocity , stride length, and  cadence ) remain unchanged during the third trimester of pregnancy and 1 year after delivery. These parameters suggest that there is no change in forward movement. There is, though, a significant increase in kinetic gait parameters, which may be used to explain how gait motion remains relatively unchanged despite increase in body mass, width and changes in mass distribution about the waist during pregnancy. These  kinetic  gait parameters suggest an increased use of hip  abductor , hip  extensor , and ankle plantar  flexor  muscle groups. To compensate for these  gait deviations , pregnant women often make adaptations that can result in musculoskeletal injuries. While the idea of "waddling" cannot be dispensed, these results suggest that exercise and conditioning may help relieve these injuries. [ 43 ]


There are many physiologic changes that occur during pregnancy that influence respiratory status and function. Progesterone has noticeable effects on respiratory physiology, increasing  minute volume  (the amount of air breathed in and out of the lungs in 1 minute) by 40% in the first trimester via an increase in  tidal volume  alone, as the respiratory rate does not change during pregnancy. [ 44 ] [ 45 ]  As a result,  carbon dioxide  levels in the blood decrease and the  pH  of the blood becomes more alkaline (i.e. the pH is higher and more basic). This causes the maternal kidneys to excrete  bicarbonate  to compensate for this change in pH. The combined effect of the decreased serum concentrations of both carbon dioxide and bicarbonate leads to a slight overall increase in blood pH (to 7.44 compared to 7.40 in the non-pregnant state) . If an  arterial blood gas  (ABG) specimen is drawn on a pregnant woman, it would therefore reveal  respiratory alkalosis  (from the decrease in serum carbon dioxide mediated by the lungs) with a compensatory  metabolic acidosis  (from the decrease in serum bicarbonate mediated by the kidneys).


As the uterus and fetus continue to enlarge over time, the diaphragm progressively becomes more upwardly displaced. This causes less space to be available for lung expansion in the chest cavity, and leads to a decrease in  expiratory reserve volume  and  residual volume . This culminates in a 20% decrease in  functional residual capacity  (FRC) during the course of the pregnancy.


Oxygen consumption increases by 20% to 40% during pregnancy, as the oxygen demand of the growing fetus, placenta, and increased metabolic activity of the maternal organs all increase the pregnant woman's overall oxygen requirements. This increase in oxygen consumption paired with the decrease in FRC can potentially mean that pregnant people with  pre-existing and/or  comorbid  asthma, pneumonia, or other respiratory issues may be more prone to disease exacerbation and respiratory decompensation during pregnancy. [ 45 ]


Maternity clothing  is worn by women as an adaptation to changes in body size during  pregnancy . The evolution of maternity clothing began during the  Middle Ages , and became fashionable as women became more selective about style and comfort in the types of maternity clothing they wore. Fashions were constantly changing over time, such as the high-waisted  Empire silhouette  style maternity dress that was fashionable at the turn of the 19th century, and the "wrapper" style  dress of the Victorian era that a woman could simply wrap around herself and button up.


The commercial production of maternity clothing began at the start of the 20th century, and continued to evolve. During the 1990s in the U.S., relaxed laws such as the  Family and Medical Leave Act , which was signed into law by President Bill Clinton, helped to protect the jobs of pregnant women, and served as a form of liberation that afforded women the freedom to wear fashionable maternity styles that emphasised their pregnancy.


Dresses did not follow a wearer's body shape until the  Middle Ages . When western European dresses began to have  seams , affluent pregnant women opened the seams to allow for growth. During the  Baroque  period (roughly 1600s through the 1700s) the  Adrienne , a waistless pregnancy gown with many folds, was popular. At that time  women wore men's  waistcoats . Some styles had laced vents in the back that allowed the wearer to adjust the girth of the coat as needed. [ 1 ]  From the 1790s through the early 1820s a style well-suited for pregnancy, the  Empire waist , was popular. The Empire, a style which has a fitted bodice ending just below the bust and a loosely gathered skirt, was made popular by Napoleon's first wife  Empress Joséphine .  Bibs could be added to permit breastfeeding. The 1960s saw a revival of the Empire waistline which lasted for a few years as a general fashion, but remained popular for many years as pregnancy wear. [ 1 ]


During the  Victorian era , women spent more time in pregnancy compared to the 21st century, giving birth to an average of eight children with five making it through infancy. [ 2 ]  Queen Victoria herself had nine.  Pregnancy was considered a private matter not to be discussed in "polite" conversation. A garment called a "wrapper" worn by women at home before they dressed for the day was well-suited for pregnancy as well since it wrapped around and could be worn loosely or more form-fitting as needed. At that time women were used to wearing  corsets  and maternity corsets with laces for adjustment were available. [ 3 ] [ 4 ]


High-waisted gowns remained in style until about 1830 but when waists returned to normal levels maternity wardrobe planning became more difficult.  In the 1840s and 1850s a fan pleated bodice was popular.  Some styles were gathered at the shoulder with a drawstring at the waist which could be let out as needed.  Separates were introduced in the 1860s with boxy jackets and gathered center bodice panels.  Some outfits had linings intended to lace over the belly for support.  Fashion magazines showed maternity clothing, though the word "pregnancy" or similar was never mentioned, instead wording such as "for the recently married lady", or "for the young matron" was used. [ 5 ]


The first commercial  ready-to-wear  clothing for pregnant women was sold in the US by  Lane Bryant  in the 1900s. Lane Bryant offered  shirtwaists  with an adjustable  drawstring  waist, and dresses with an adjustable wrap-around front. [ 4 ] [ 6 ]


The next competitor, Page Boy, offered a  patented  skirt in 1937. By the 1930s, wrap-around skirts with a series of buttons were available, but the new Page Boy skirt was constructed with a window over the area of the expanding abdomen which allowed the hemline to remain stable rather than to hike up as the woman's abdomen increased in size. In later years when stretch fabric became available it was used to fill in the window. [ 4 ]  Their clothing, usually a slim skirt with a wide smock top, became fashionable during the 1950s [ 4 ]  after  Lucille Ball  popularized the style in the first TV episode to show a pregnant woman in 1952. [ 7 ] [ 8 ]  Celebrities such as  Jackie Kennedy  and  Elizabeth Taylor  were later known for wearing Page Boy clothes. [ 4 ]


Slacks with adjustable waists became widely available in the 1950s. An  Aldens  catalog from 1952 shows a  pedal pusher  and matching blouse outfit priced at $5.98. [ 9 ]  Designer blue jeans became available in the '80s. [ 4 ]


Further developments in maternity clothing styles have meant that many maternity tops are also made to enable discreet nursing, extending the usable life of maternity clothes beyond just the period whilst pregnant. [ citation needed ]


Maternity clothes around the world have been undergoing significant changes. In both Eastern and Western cultures, there is greater demand for fashionable maternity clothes. In Western cultures the influence of celebrity culture. [ 10 ] [ 11 ]  means that pregnant women in the public eye are taking the lead in maternity fashion. [ 12 ]   One such example is  Demi Moore 's 1991  Vanity Fair  cover, which was one of the first instances of a magazine cover depicting an expectant mother. [ 13 ]  As a result, pregnant women are no longer trying to hide or disguise their "baby bumps", instead choosing to wear garments which closely fit their new shape, often emphasising the bust and abdominal area. Fashion bloggers have caught on to the shift in perception  and began to regularly discuss new styles and fabrics designed with the pregnant form in mind. [ 14 ]  High-tech fabrics such as elastane are the material of choice for maternity wear in Western cultures as they allow garments to be form-fitting while allowing the abdominal area to expand as necessary.


Women in Eastern cultures, however, have maintained a much greater sense of modesty when it comes to maternity wear. In both the Islamic and Asian cultures, maternity wear is much less fitted, hemlines are longer and necklines higher. Modern Islamic maternity wear uses fabrics with brighter colours and bolder prints. [ 15 ]  Aside from cultural modesty, Chinese women have sometimes sought to hide their second pregnancy in less shapely clothes because Chinese policy has dictated that they can only have one child. In Chinese and Japanese cultures, there is a fear of radiation from devices such as computers and mobile phones, especially during pregnancy. Even though there is no evidence to support this (according to WHO [ 16 ] ), Asian maternity wear is often manufactured from "anti-radiation" fabrics. [ 17 ]


Culturally in the US today, a few popular clothing brands have made everyday wear for pregnant women both fashionable and accessible.  As the body is changing shape and therefore levels of comfort, most maternity clothing is made with Lycra and elastic for stretch and growth. For pants, the waistband is usually a thick layer of stretchy material that can be hidden by a shirt to give the pants a normal look. Depending on style and activity, tops often billow out to leave room for the belly and are made of varying cottons and elastic materials.


As more women are pregnant when they marry, some manufacturers of maternity clothing and bridal gowns have begun producing  wedding dresses  that fit pregnant women. [ 18 ]


While women were integrated into the U.S. military  in 1948, they were automatically discharged if they became pregnant.  However, in the late 1970s it was decided that in order to keep women in an all-volunteer armed forces the military needed to change its policy regarding pregnancy. Following complaints that pregnant women dressed in civilian clothing undermined morale, between 1978 and 1980 the armed forces began to issue military maternity outfits. Writing about her experience working on the Armed Forces History Collections  at the  Smithsonian National Museum of American History , museum expert Bethanee Bemis wrote (in 2011):


Bemis wrote in 2011 that of the more than 6,000 military uniforms in their collection only three were maternity uniforms,  an Air Force officer's uniform and two Navy Petty Officer Second Class uniforms.  The Air Force dress uniform features a blue smock top paired with a white blouse and blue skirt, and the Navy uniforms include a blue coat and slacks with a white blouse for dress and a working uniform with   dungaree pants  and a  chambray  shirt.  All three uniforms are from the 1980s. [ 19 ]


Speaking at the  International Women's Day  celebration in March 2021, President Joe Biden spoke of the progress that the military has taken in recent years to better accommodate women in the military, including creating maternity flight suits and new better fitting body armor.   Tucker Carlson , speaking on  Fox News , showed a photo of an Air Force officer wearing an artificial pregnancy bump to demonstrate the design changes that made for the new Maternity Flight Duty Uniform and commented "So, we've got new hairstyles and maternity flight suits.  Pregnant women are going to fight our wars. It's a mockery of the U.S. military." The Pentagon's top spokesman and senior generals rebuked Carlson's remarks.   His comments also drew numerous social media responses from both male and female enlisted service members, some of whom noted that Tucker has never served. Army veteran Senator  Tammy Duckworth , who lost both her legs during a deployment in Iraq and notably the first sitting senator to give birth while in office, responded to Carlson with a tweet referencing his brief appearance on  Dancing with the Stars :
"While he was practicing his two-step, America's female warriors were hunting down Al Qaeda and proving the strength of America's women." [ 20 ]


Pregnancy fashions took a dramatic turn in the 1990s with the introduction of tight-fitted maternity wear intended to emphasize rather than hide a pregnant woman's baby bump. Not coincidentally, this shift occurred during a time of major changes for women in America. In 1993, the  Family and Medical Leave Act  was passed by President Bill Clinton. This act protected women's jobs during pregnancy, giving women more freedom to show off their pregnancies. [ 21 ] [ 22 ]


Until this act was passed, many women were fired as a result of their pregnancies. Following the passage of this legislation women had more job security  and  government-protected maternity leave. At the same time as these laws were being passed, maternity fashions changed drastically.  Many  magazine articles began to discuss stylish mothers-to-be wearing figure hugging clothing that emphasized their growing waistline. [ 12 ]


Historically maternity clothing has not generally been considered a potentially profitable area for most major clothing manufacturers due to a belief that many women would not purchase clothes intended for only a few months of wearing. [ 23 ]   Declining birth rates have also reduced sales. [ 4 ]  However, with wide media interest in celebrity pregnancies beginning in the late 1990s, the maternity wear market grew 10% between 1998 and 2003. [ 10 ]  It was also during this time that the term "pregnant chic" was developed in order for companies to market to pregnant women. [ 24 ]  One clothing source said the demand for maternity clothes was growing because "Nowadays women are working during pregnancy, and travelling, and going to the gym, so their clothing needs are greater and more diverse." [ 25 ]


In 2015 it was reported that maternity clothes is a $2.4 billion market in the U.S. According to a  Forbes  analysis, in 2014 a pregnant woman spent around $480 on maternity wear. [ 26 ]    This represents approximately one-sixth of all clothing sales each year. The largest chains, belonging to Destination Maternity, control almost one-fifth of the American market. Other brands are sold through discount stores, department stores, and boutiques. [ 4 ]


Maternity clothing is generally worn only during the second and  third trimesters, and possibly for several weeks or months after the birth of the baby while a woman regains her pre-pregnancy size. If a woman expects to be pregnant only once or twice, buying maternity clothing that will be worn only for about six months, can be considered expensive. Women who cannot afford or don't want to spend large amounts of money on maternity clothing may choose to just wear either larger, looser clothing or buy secondhand maternity clothes via yard sales and also  consignment  clothing stores. Also, some products, such as button extenders or Ingrid & Isabel's Bellaband wrap, are intended to work with the woman's non-maternity clothing, to reduce the need for specialized clothing. [ 4 ]


A  maternity home,  or  maternity housing program , is a form of  supportive housing  provided to pregnant women. Maternity housing programs support a woman in need of a stable home environment to reach her goals in a variety of areas including education, employment, financial stability, prenatal care, and more. There are over 400 maternity homes in the United States [ 1 ]  ranging in size and criteria for admittance.  Staffing model is a primary way that maternity homes differ. The three major staffing models are houseparents (e.g. a married couple), live-in staff, and shift staff. Additionally, there are a limited number of maternity housing program who operate as a "shepherding" or "host" home. In the "host home" model, women are connected to screened households that offer to provide housing.


In other countries, the term "maternity home" may refer to the above described or may describe a temporary residence for pregnant women awaiting birth, which might include women who must travel long distances for medical care or high-risk pregnancies who are receiving frequent care. Maternity homes are not to be confused with  maternity hospitals , or other facilities in which women give birth. Another sort of temporary housing for pregnant women are the maternity hostels that have become widespread in countries  such as India  where commercial  surrogacy  is big business. [ 2 ]


Maternity homes used to be known as homes for unwed mothers, as  illegitimacy  was (and in some places still is) a social taboo.


The Salvation Army  opened its first one in 1886. [ 3 ]  Other examples include Bethany Home [ 4 ]  in Minneapolis, later renamed Harriet Walker Hospital. [ 5 ]


Prior to the 1980s, housing for pregnant women was offered in larger, institution-like settings that were strongly adoption-oriented. In these homes, confidentiality was a priority due to the social stigma around unwed births and the policies reflected the adoption laws and practices of the time.  From these settings grew many of the  narratives  around maternity homes that continue to this day (e.g.  women forced into adoption ; preventing  birth mothers  from seeing their  new borns ; concealing placement details).  [ citation needed ]


In the 1970s and 1980s, the adoption process began to grow in flexibility (e.g. changes to father notification, no longer making short-term placements of adopted babies into foster care, making use of probate court adoptions rather than solely via adoption agencies, increased inter-state adoptions.) Offering a more flexible housing option via a new model paralleled the more flexible adoption process.  The large, institutional maternity homes began to close during this time.


In the early 1970s, Anne and Jim Pierson were pioneers in the host home model and publicly recognized by  President Reagan  for their family-style method of welcoming pregnant women. Shepherding or host homes grew in popularity in the 1980s and 1990s as a new type of housing resource. In this model, pregnant women in crisis pregnancies were housed within the spare bedrooms in the homes of passionate volunteers during their pregnancy. Several longstanding maternity homes used some version of a host home living environment as the launching point for developing a housing program. Additionally, many founders of longstanding maternity homes (and other pregnancy help organizations) began by welcoming women into their own home. [ citation needed ]


Some maternity homes, such as the  Bon Secours Mother and Baby Home  in  Tuam , were found to have provided highly substandard care.   [ citation needed ]


The  American Red Cross  sponsored maternity hostels in London after  World War I . [ 6 ]


Medical imaging in pregnancy  may be  indicated  because of  pregnancy complications ,  intercurrent diseases  or routine  prenatal care .


Options for  medical imaging  in  pregnancy  include the following:


Magnetic resonance imaging  (MRI), without  MRI contrast agents , is not associated with any risk for the mother or the fetus, and together with  medical ultrasonography , it is the technique of choice for medical imaging in pregnancy. [ 1 ]


For the first trimester, no known literature has documented specific adverse effects in  human embryos  or fetuses exposed to non-contrast MRI during the  first trimester . [ 3 ]  During the second and third trimesters, there is some evidence to support the absence of risk, including a retrospective study of 1737 prenatally exposed children, showing no significant difference in hearing,  motor skills , or functional measures after a mean follow-up time of 2 years. [ 3 ]


Gadolinium contrast  agents in the first trimester are associated with a slightly increased risk of a childhood diagnosis of several forms of  rheumatism ,  inflammatory disorders , or infiltrative  skin conditions , according to a retrospective study including 397 infants prenatally exposed to gadolinium contrast. [ 3 ]  In the second and third trimesters, gadolinium contrast is associated with a slightly increased risk of stillbirth or neonatal death, by the same study. [ 3 ]  Hence, is recommended that gadolinium contrast in MRI should be limited, and should only be used when it significantly improves diagnostic performance and is expected to improve fetal or maternal outcomes. [ 1 ]


Women have a legal right to not be forced to undergo medical imaging without first providing informed consent; a radiologist is usually the healthcare provider trained to enable informed consent. [ 4 ]


MRI is commonly used in pregnant women with acute  abdominal pain  and/or  pelvic pain , or in suspected  neurological disorders ,  placental diseases ,  tumors ,  infections , and/or  cardiovascular diseases . [ 3 ]   Appropriate use criteria  by the  American College of Radiology  give a rating of ≥7 (usually appropriate) for non-contrast MRI for the following conditions:


Health effects of radiation  may be grouped in two general categories:


The determinstistic effects have been studied at for example survivors of the  atomic bombings of Hiroshima and Nagasaki  and cases of where  radiation therapy  has been necessary during pregnancy:


The intellectual deficit has been estimated to be about 25  IQ-points  per 1,000 mGy at 10 to 17 weeks of gestational age. [ 1 ]


The risk for the mother of later acquiring  radiation-induced   breast cancer  seems to be particularly high for radiation doses during pregnancy. [ 6 ]


This is an important factor when for example determining whether a  ventilation/perfusion scan  (V/Q scan) or a  CT pulmonary angiogram  (CTPA) is the optimal investigation in pregnant women with suspected  pulmonary embolism . A V/Q scan confers a higher radiation dose to the fetus, while a CTPA confers a much higher radiation dose to the mother's breasts. A review from the  United Kingdom  in 2005 considered CTPA to be generally preferable in suspected pulmonary embolism in pregnancy because of higher  sensitivity and specificity  as well as a relatively modest cost. [ 7 ]


Melasma  (also known as  chloasma faciei , [ 1 ] : 854   or the  mask of pregnancy [ 2 ]  when present in  pregnant women ) is a tan or dark skin discoloration. Melasma is thought to be caused by sun exposure, genetic predisposition, hormone changes, and skin irritation. [ 3 ]  Although it can affect anyone, it is particularly common in women, especially pregnant women and those who are taking  oral  or patch  contraceptives  or  hormone replacement therapy  medications. [ 3 ]


The symptoms of melasma are dark, irregular, well-demarcated, hyperpigmented  macules  to patches. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration. [ 4 ]  Patches can vary in size from 0.5 cm (0.2 in) to larger than 10 cm (4 in) depending on the person. Its location can be categorized as centrofacial, malar, or mandibular. The most common is centrofacial, in which patches appear on the cheeks, nose, upper lip, forehead, and chin. The mandibular category accounts for patches on the bilateral rami, while the malar location accounts for patches only on the nose and cheeks. [ 5 ]


The exact cause of melasma is unknown. [ 6 ]


Melasma is thought to be the stimulation of  melanocytes  (cells in the  dermal  layer, which transfer the  pigment   melanin  to the  keratinocytes  of skin) when the skin is exposed to ultraviolet light from the sun. Small amounts of sun exposure can make melasma return to the skin after it has faded, which is why people with melasma often get it again and again, particularly in the summer. [ 3 ]


Pregnant women often get melasma, or chloasma, known as the mask of pregnancy. Birth-control pills and hormone replacement therapy also can trigger melasma. The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone treatment. [ 3 ]


Genetic predisposition is also a major factor in determining whether someone will develop melasma. People with the  Fitzpatrick skin type  III or greater from African, Asian, or Hispanic descent are at a much higher risk than others. [ 5 ]  In addition, women with a light brown skin type who are living in regions with intense sun exposure are particularly susceptible to developing this condition. [ 4 ]


The incidence of melasma also increases in patients with  thyroid disease . [ 7 ]  It is thought that the overproduction of  melanocyte-stimulating hormone   brought on by stress can cause outbreaks of this condition. Other rare causes of melasma include allergic reaction to medications and cosmetics.


Melasma suprarenale (Latin: 'above the kidneys') is a symptom of  Addison's disease , particularly when caused by pressure or minor injury to the skin, as discovered by FJJ Schmidt of Rotterdam in 1859. [ citation needed ]


The two different kinds of melasma are epidermal and dermal.


The severity of facial melasma may be assessed by  colorimetry , mexametry, and the melasma area and severity index (MASI) score. [ 6 ]


Melasma should be differentiated from  freckles ,  solar lentigo , toxic melanoderma,  Riehl melanosis , post-inflammatory  hyperpigmentation , friction melanosis,  ochronosis  (endogenous and exogenous), and cutaneous erythematosus  lupus . [ 8 ]   Additionally, it should not be confused with phytophotodermatosis,  pellagra , endogenous  phototoxicity ,  nevus of Ota ,  café au lait macules ,  seborrheic keratosis ,  Poikiloderma of Civatte , acquired bilateral nevus of ota-like macules ( Hori's nevus ),  periorbital hyperpigmentation , erythrose pigmentaire peribuccale of Brocq,  erythromelanosis follicularis faciei , facial  acanthosis nigricans , and  actinic lichen planus . [ 8 ]


Also, cases of drug-induced pigmentation have been reported, caused by  amiodarone , or hydroquinone-induced exogenous ochronosis (see  ochronosis treatment ). [ 8 ]


Assessment by a dermatologist can help guide treatment. Treatments to hasten the fading of the discolored patches include:


Evidence-based reviews found that the most effective therapy for melasma includes a combination of topical agents. [ 10 ] [ 9 ]  Triple combination creams formulated with  hydroquinone ,  tretinoin , and a steroid component have shown to be more effective than dual combination therapy or hydroquinone alone. [ 21 ]  More recently, a systematic review found that oral medications also have a role in melasma treatment, and have been shown to be efficacious with a minimal number and severity of adverse events. Oral medications and dietary supplements employed in the treatment of melasma include  tranexamic acid ,  Polypodium leucotomos  extract, beta‐carotenoid,  melatonin , and  procyanidin . [ 22 ]


Oral procyanidin combined with vitamins A, C, and E shows promise as safe and effective for epidermal melasma. In an 8-week randomized, double-blind, placebo-controlled trial in 56  Filipino  women, treatment was associated with significant improvements in the left and right malar regions, and was safe and well tolerated. [ 23 ]


In all of these treatments, the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc oxide, is preferred, [ 24 ]   because UV-A, UV-B, and visible lights are all capable of stimulating pigment production.


Many negative side effects can go along with these treatments, and treatments often are unsatisfying overall. Scarring, irritation, lighter patches of skin, and  contact dermatitis  are all commonly seen. [ 6 ]  Patients should avoid other precipitants, including hormonal triggers.  Cosmetic camouflage  can also be used to hide melasma.


The health of a mother directly affects the fetus during pregnancy. High levels of vehicle pollution where pregnant women reside can have adverse health effects on fetuses.


In the United States about 10% of the population, 33 million people, live within 900 meters of a high  traffic   road [ 1 ]  High-traffic roads are commonly identified as being host to more than 50,000 vehicles per day, which is a source of toxic vehicle  pollutants . [ 2 ]  Previous studies have found correlations between exposure to vehicle pollutants and certain diseases such as  asthma ,  lung  and  heart disease , and  cancer  among others. Car pollutants include  carbon monoxide ,  nitrogen oxides ,  particulate matter  (fine dusts and soot), and toxic  air pollutants   [ 3 ]  While these pollutants affect the general health of populations, they are known to also have specific adverse effects on expectant mothers, their fetuses and children. The purpose of this article is to outline how vehicular pollutants affect the health of expectant mothers and the adverse health effects these exposure have on the adult.


Areas with high levels of nitrogen dioxide in the air, which is an output of vehicular air-pollution, are shown to have negative effects on fetuses. Effects of the exposure include reduced fetal growth, premature birth, and respiratory conditions. Two studies were conducted to evaluate the effects of nitrogen dioxide on fetuses in the southern United States as well as Valencia Spain. In the United States, babies that were born prematurely were 94% more likely to have been exposed to high levels of pollution than those that were not premature. In Spain, fetuses that were small for gestational age in terms of weight were 37% more likely to have been exposed to high levels of air pollution than those that were not small for gestational age in terms of weight. [ 4 ] [ 5 ]


In Los Angeles County, researchers found a higher risk in  premature birth  (10-20%) and low  birth weight  for infants whose mothers lived near high traffic areas  [ 6 ]  Studies conducted on populations living near the 405 and 710 interstates in Southern California found their exposure to particulate vehicle emissions to be almost 25 times higher than for people living 1000 ft from the  freeways . This research also concluded that particulate vehicle emissions are more toxic to children's health than other particles such as Carbon Monoxide and Nitrogen Dioxide  [ 7 ] [ 8 ]


Carbon monoxide (CO) is directly released from motor vehicles engines, which are a major source of this pollutant in the  LA Basin [ 8 ]  5. CO inhaled by pregnant women may threaten the unborn child's growth and mental development. Because CO competes with Oxygen to achieve dispersion throughout the blood stream, fetal hypoxia (lack of oxygen) may result at high levels of maternal CO exposure, however the exact amount of exposure of CO to become a fetal threat is unknown  [ 9 ]  High levels of carbon monoxide are also found in cigarettes, it is advised that pregnant women avoid smoking so as to not run the risk of affecting their child's growth or mental development. For further information on Carbon Monoxide and its effects on human health please see,  Carbon monoxide poisoning .


Nitrogen oxides (NO) are common air pollutants found throughout most of the United States. You can be exposed to these oxides by breathing polluted air, which is most commonly found in areas with heavy  motor vehicle  traffic  [ 10 ]  Exposure to high levels of Nitrogen oxides damages tissues of the throat and upper  respiratory tract  and can interfere with the body's ability to carry oxygen. High exposure to nitrogen dioxide may cause fetal mutations, damage a developing fetus, and decrease a woman's ability to become pregnant. Studies have also shown that higher exposures to NO inhibit embryo development during both traditional pregnancies and artificial inseminations  [ 11 ] [ 12 ]


Examples of particulate matter include ash from smoke in campfires, dust particles around your house, and smoke coming from car exhaust pipes; in areas close to freeways this is a problem. A study conducted on European women indicated that higher exposure to particulate matter during the initial first weeks of their pregnancy resulted in low birth weight babies  [ 13 ]  This toxin is also considered to be the most dangerous of the three because it can be basically anything small enough to be inhaled. This may also be due to the fact that brain growth begins within the first month of conception.


A previous study conducted in the Los Angeles Basin of  Southern California  reported a consistent association between levels of CO and particulate matter during the first trimester and the last six weeks prior to birth and risk of preterm birth.  Prematurity  in babies is accompanied by an array of health complications. Children born prematurely are at highest risk for developing  Infant respiratory distress syndrome ,  gastrointestinal , and  hematologic  diseases, central nervous system (CNS) problems such as hearing loss, are more prone to infections, and at risk for hearing and vision loss.


Babies born of low weight are also at risk for respiratory, gastrointestinal, cardiac, CNS, infection and vision problems. These gestational issues persist until the adult years for most children and result in high blood pressure, Type II Diabetes, and other heart diseases.


Prematurity and Low Birth Weight caused by air pollution also affects fetal brain development. This is of importance since lack of proper brain development will not allow a child's brain to form proper synapse connections which will negatively affect the child's speech, learning abilities, and social skills.


Exposure to air pollution not only affects newborns in early stages of their development, it can also have lifelong consequences for children exposed from the time of conception to when they reach two years of age. Air pollution has been found to cause lower birth weights, insufficient development of the immune system and organs, and premature births. These birth effects have been linked to respiratory issues that can persist into one's long-term health. [ 14 ]


Exposure to vehicle air pollutants has been noted as primary cause for infant mortality and morbidity, and is also argued to be a cause of chronic diseases such as asthma in child and adulthood  [ 15 ]


The number of children affected by asthma has increased in past decades the point where it is now the most chronic illness in children and the most common cause of children hospitalizations in the U.S. causing it to also be a number one contributor to school absences [ 16 ]  Excessive school absences ultimately affect the child's learning ability, and decrease their time to socialize with kids their age. It is not uncommon for children who suffer from asthma to oftentimes repeat grades due to failure to keep up academically. If students are not repeating grades they are highly likely to dropout prior to graduation over their non-affected peers. [ 17 ]


Studies have found that children who are exposed to higher levels of car pollutants report higher respiratory problems including wheezing, ear and throat infections and have a higher incidence of physician-diagnosed asthma. [ 18 ] [ 19 ]  Bronchiolitis is also found in greater amounts when the child's home is around high amounts of traffic. [ 20 ]


Children living in close proximity to high traffic areas are also eight times more likely to develop leukemia compared to children who do not  [ 21 ]  This finding indicates that children who develop cancer as a result of traffic exposure will also spend more time in the hospital. This is not only a cause of school absences, but also a time of trauma for a child who is constantly visiting providers for treatment. Children with cancer have a harder time keeping up with school and keeping up with their friends  [ 22 ]


Autism  is a spectrum of disorders that range from a severe inability to communicate and some mental disabilities to milder symptoms such as attention disorders. Some claims exist that the incidence of autism is higher for babies whose mothers spend time in ‘high traffic pollution’ areas compared to mothers who spend their pregnancy in cleaner air. In a recent study conducted by UCLA, air pollutant levels were measured for mothers who had children with autism and then compared to air pollutant levels in environments for mothers who had children without autism. This study found that babies who were exposed to higher levels of pollutants while in the womb had a 10% higher risk of autism than babies who had low levels of exposure; another finding from this study is that fine particulates had the strongest association with autism  [ 23 ]


Motor vehicle emissions are not solely a United States issue. Of the 10 cities with the most traffic, there are no cities from the United States listed. [ 24 ]  The United States also has regulations regarding what and how many emissions vehicles are allowed to emit that are on the road. This is done by the USEPA and they are currently working on new regulations. [ 25 ]  Of the countries that have vehicle emission standards, the European Union and Japan have the most strict regulations. These standards have been added because it is shown that regulating fuel economy is effective in controlling oil demands for the country as well as reducing their greenhouse emissions. [ 26 ]


Respiratory and allergic disorders among children in Japan were studied after the implementation of new regulations were put in place and it showed the prevalence of asthma and other respiratory disorders decreased. [ 27 ]  There have also been more recent studies showing that the incidence of asthma cases worldwide is increasing in children. Much of this increase is due to the increase in NO2 which is a gas that is emitted from motor vehicles among other sources. [ 28 ]


Across the United States, vehicle emissions make up a large portion of air pollution, especially in urban areas. An epidemiological study conducted by the National Institute of Health compared pregnancy loss to local vehicle emissions, specifically nitrogen dioxide (NO₂). The study used data from Boston, Massachusetts and Tel Aviv, Israel, and both regions observed associations between pregnancy loss and NO₂, largely in the second trimester of pregnancies. This study further increases scientific confidence that vehicle emissions can be detrimental to pregnant individuals and fetuses and that these findings are consistent in different geographic locations and among different populations. [ 29 ]


Safina Namukwaya  is the oldest living woman in Africa to give birth at an old age. She achieved this feat on 29 November 2023 after she gave birth to twins (girl and boy) at 70 years in Uganda. [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ]


Namukwaya lives in Nunda village, Lwabenge parish, Buyiisa sub-county which is located in  Kalungu district . [ 9 ] [ 10 ] [ 11 ] [ 12 ] [ 13 ] [ 14 ]  She got married at the age of 15 in 1973. [ 9 ]  She suffered a miscarriage when her pregnancy reached 22 weeks old. [ 9 ] [ 10 ] [ 15 ]  After nine years, Safina was diagnosed with blocked fallopian tubes and received her treatment at  Masaka  Regional Referral Hospital. [ 9 ] [ 10 ]


Safina married Badru Walusimbi in 1996 after the death of her first husband in 1992. [ 9 ]


In July 2018, Namukwaya visited the  Women's Hospital International and Fertility Center  where was diagnosed with blocked fallopian tubes for and was given treatment. [ 9 ] [ 15 ]  (source needs to be verified, as this conflicts with above information)


On 9 November 2019, five embryos were transferred into Namukwaya's womb and when the pregnancy test was carried out in November 2019, she had conceived through  In vitro fertilization  ( IVF ) at the first trial. [ 9 ]  She started experiencing signs of pregnancy such as morning sickness. [ 9 ]


On 9 December 2019, the results from the ultrasound scan confirmed that Namukwaya was carrying a 6 weeks pregnancy. [ 9 ]


On 20 March 2020, Namukwaya started attending her antenatal care when the pregnancy reached 19 weeks at Masaka Regional Referral Hospital instead of travelling to  Women's Hospital International and Fertility Center  as it was very far. [ 9 ]


Namukwaya initially gave birth to a baby girl in 25 June 2020 [ 16 ] [ 9 ] [ 10 ] [ 17 ] [ 6 ] [ 18 ] [ 8 ] [ 19 ]  at Masaka Regional Referral Hospital [ 20 ] [ 11 ] [ 13 ]  before giving birth to twins via caesarean section at  Women's Hospital International and Fertility Center  (WHI&FC) in Kampala on 29 November 2023 between 12:04pm and 12:05pm East African Time. [ 1 ] [ 4 ] [ 10 ] [ 21 ] [ 7 ] [ 22 ] [ 8 ]  The babies were produced prematurely at a  gestation period  of 31 weeks and were transferred to  WHI&IF 's neonatal intensive care unit for incubation.  [ 2 ] [ 4 ] [ 23 ] [ 24 ]  She got pregnant by  In vitro fertilization  treatment. [ 25 ] [ 26 ] [ 27 ] [ 23 ] [ 28 ]


Circa 1990s, Safina had miscarriages thus unable to give birth. [ 25 ]


Navicular cell  is a boat-shaped benign  epithelial cell  seen in  Pap smear . [ 1 ]  They are seen in pregnancy (most prominently during smears taken in the second trimester), [ 2 ]  second half of  menstrual cycle , during menopause and in women using  medroxyprogesterone acetate  (depo-provera) for contraception. Navicular cells have folded edges, with a thickened outer rim of cytoplasm and an eccentric nucleus. They contain abundant glycogen in the cytoplasm, giving it a central yellow halo. The cytoplasm appears golden, refractile and granular under the microscope. In depo-provera users, the high progesterone levels result in more exfoliation of superficial squamous cells, thereby causing navicular cells to appear in Pap smear. [ 3 ]


Neonatal infections  are infections of the  neonate  (newborn) acquired during  prenatal development  or within the first four weeks of life. [ 1 ]  Neonatal infections may be contracted by  mother to child   transmission , in the  birth canal  during  childbirth , or after birth. [ 2 ]  Neonatal infections may present soon after delivery, or take several weeks to show symptoms. Some neonatal infections such as  HIV ,  hepatitis B , and  malaria  do not become apparent until much later. Signs and symptoms of infection may include  respiratory distress , temperature instability,  irritability ,  poor feeding ,  failure to thrive , persistent crying and skin rashes.


Risk factors include previous maternal infection,  preterm delivery  (< 37 weeks gestation) and  premature rupture of membranes  (breakage of the  amniotic sac ) which substantially increases the risk of  neonatal sepsis  by allowing passage for bacteria to enter the womb prior to the birth of the infant. Preterm or  low birth weight  neonates are more vulnerable to neonatal infection. While preterm neonates are at a particularly high risk, all neonates can develop infection. Maternal screening for intrapartum infections reduce the risk of neonatal infection. Pregnant women may receive intrapartum antibiotic prophylaxis for prevention of neonatal infection. [ 3 ]


Infant respiratory distress syndrome  is a common complication of neonatal infection, a condition that causes difficulty breathing in preterm neonates. Respiratory distress syndrome can arise following neonatal infection, and this syndrome may have long-term negative consequences. In some instances, neonatal respiratory tract diseases may increase the susceptibility to future respiratory infections and inflammatory responses related to lung disease. [ 4 ]


Antibiotics  can be effective for neonatal infections, especially when the  pathogen  is quickly identified. Instead of relying solely on culturing techniques, pathogen identification has improved substantially with advancing technology; however,  neonate mortality  reduction has not kept pace. In industrialized countries,  treatment  for neonatal infections takes place in the  neonatal intensive care unit  (NICU). Neonatal infection can be distressing to the family and it initiates concentrated effort to treat it by  clinicians . Research to improve treatment of infections and prophylactic treatment of the mother to avoid infections of the infant is ongoing. [ 5 ]


Signs and symptoms of infection include respiratory distress, temperature instability, irritability, failure to thrive, and skin rashes. [ citation needed ]


Early-onset sepsis (EOS), defined as onset of symptoms within 72 hours of life, is generally caused by transmission of  pathogens  from the  female genitourinary system  to the fetus. Pathogens can infect the fetus via  vertical transmission  (direct transmission through the placenta in utero) or infection during delivery as fetus passes through  vaginal canal.


Late-onset sepsis (LOS), defined as onset of symptoms after 72 hours of life, is generally caused by transmission of pathogens from the environment after delivery. Infants requiring intravascular catheters and other invasive procedures are at increased risk for developing LOS. [ 3 ]


There are many etiologies of neonatal infection, including bacterial, viral and fungal pathogens. The source of infectious  bacteria  and other pathogens is often the  maternal   gastrointestinal  and  genitourinary tract . Many of the maternal infections with these organisms are  asymptomatic  in the mother. Other maternal infections that may be transmitted to the infant in  utero  or during birth are bacterial and viral  sexually transmitted infections . The infant's ability to resist infection is limited by its immature  immune system . In addition, the immune system of the neonate may respond in ways that can create problems that complicate treatment, such as the release of  inflammatory chemicals . Congenital defects of the immune system also affect the infants ability to fight off the infection. [ 6 ]


Bacteria found in the maternal gastrointestinal or gastrourinary tracts can commonly lead to neonatal infection. Bacterial infections may present as fetal distress at birth (including signs of tachycardia, temperature instability or difficulty breathing), neonatal sepsis, or neonatal meningitis. Infections that develop during NICU admissions are more commonly coagulase-negative staphylococci, especially in infants with indwelling catheters. Infections that develop one month after the birth of the infant are more likely due to  gram-positive bacteria  and  coagulase positive staphylococci . [ 7 ]     ...


Group B streptococcus  (GBS), also named  Streptococcus agalactiae , is a bacteria typically identified as the cause of the majority of early-onset infections in the neonate. GBS is an encapsulated gram-positive cocci that colonizes the gastrointestinal and genital tracts of pregnant women. Maternal infections are usually asymptomatic. This pathogen is  vertically transmitted  (transmitted directly from the mother's vagina into the infant's amniotic fluid after onset of labor). Due to the high prevalence of GBS, routine screening for the bacteria occurs during pregnancy. If the bacteria is found in the maternal GI / GU tract, mothers will receive IV antibiotic (usually penicillin or ampicillin). [ 8 ]


Escherichia coli  is an encapsulated gram-negative bacilli that may cause neonatal infections due to its high prevalence in the GI and GU tracts of pregnant patients. With the advances in preventing group B streptococcus infections, β-lactam-resistant  Escherichia coli  infections have increased in causing neonatal deaths in very low birthweight and premature infants. Common complications of neonatal E.coli infection include neonatal sepsis and neonatal meningitis. [ 9 ]


Neisseria gonorrhoeae  is a common  sexually transmitted infection  which may be present in pregnant women at time of delivery. This pathogen is usually acquired during delivery, occurring in 30-40% of cases with known maternal infection. Additionally, untreated maternal gonorrhea may increase the risk of  preterm delivery.  The most common manifestation of gonococcal infection in a newborn is  neonatal conjunctivitis , an infection of the eyes that presents with green-yellow  exudate  and eyelid swelling. Without treatment, this infection can lead to permanent  visual impairment . Treatment of  Neisseria gonorrhoeae  conjunctivitis consists of a single dose of  ceftriaxone  (antibiotic). Typically, all neonates (regardless of symptoms or risk factors) receive  erythromycin  ointment applied to both eyes after delivery [ 10 ]


Listeria monocytogenes  is a gram-positive bacilli that can cause infection acquired from  tainted food  and present in the mother. The presence of this pathogen can sometimes be determined by the symptoms that appear as a  gastrointestinal illness  in the mother. The mother acquires infection from ingesting food that contains  animal products  such as  hot dogs ,  unpasteurized   milk ,  delicatessen meats , and  cheese . [ 11 ]


Clostridium tetani  can cause a generalised form of  tetanus  in the neonate. This usually occurs when the mother has not been vaccinated against tetanus and the baby has not acquired passive immunity. The umbilical cord region is the most susceptible. [ 12 ]


Less common bacterial pathogens include  Streptococcus pyogenes ,  Viridans streptococci ,  Streptococcus pneumoniae ,  Haemophilus influenzae , and  Pseudomonas aeruginosa . [ 13 ] [ citation needed ]


Human immunodeficiency virus  (HIV) infection can occur during delivery of the neonate, in utero through mother-to-child transmission or postnatally by way of breastfeeding. Most transmission occurs during delivery. Transmission depends on multiple risk factors, usually centered around the viral load of HIV in the mother. Strategies for reducing transmission of HIV include:


Symptoms of HIV in a child will vary depending on the age of presentation. Common symptoms include  failure to thrive , recurrent infections such as  pneumonia , intermittent diarrhea, swollen lymph nodes and  oral thrush . In infants, diagnostic testing for HIV relies of detection of the virus in the bloodstream. For infants born to HIV-infected mothers, diagnostic testing will be performed within days of delivery, at 1–2 months and at 4–6 months of age. [ 15 ]


Cytomegalovirus (CMV)  is the most common congenital viral infection, usually transmitted through the placenta during pregnancy. Most neonates with congenital CMV infection will not have any symptoms, but a minority of infected newborns will have symptomatic infection. Common symptoms include rash,  microcephaly  (small head),  low birth weight ,  jaundice ,  thrombocytopenia , seizures and  retinitis . Long-term complications of congenital CMV infections may include  sensorineural hearing loss ,  developmental delay , and seizures. Due to high prevalence of disease, CMV is not routinely screened in pregnant patients. [ 16 ]


Herpes simplex virus  (HSV), which commonly causes cold sores and painful genital blisters can cause congenital infection via direct contact with genital tract lesions during delivery. Neonatal HSV may be classified into three categories based on symptom presentation:


Maternal infection with  rubella virus  during pregnancy can lead to  congenital rubella syndrome . The risk of congenital infection is highest during the first trimester (< 12 weeks). Risk of congenital rubella is increased among immigrant women from countries without adequate vaccination programs. Common symptoms include  cataracts ,  hearing impairment ,  developmental delay  and  congenital heart disease. [ 18 ]


Zika virus is an arthropod-borne virus transmitted by  mosquitos , and infection during pregnancy can lead to severe congenital abnormalities in a newborn. Congenital infection can lead to  fetal growth restriction  and CNS abnormalities, including  microcephaly ,  ventriculomegaly  and intracranial calcifications. [ 19 ]


There are five liver specific viruses (hepatitis A, B, C, D, E) that could potentially harm the mother and child. Acute hepatitis A virus or acute hepatitis E virus infection present the greatest risk to maternal and fetal health and increased risk of adverse pregnancy outcomes. Hepatitis B, C and D virus present a risk of mother to child transmission but are dependent on the severity of the underlying disease in the mother. However, hepatitis B virus is the major cause of neonatal infection. [ 20 ]


Other viral infections, such as  respiratory syncytial virus  (RSV),  metapneumovirus  (hMPV),  rhinovirus ,  parainfluenza  (PIV), and  human coronavirus  in the neonatal period are associated with recurrent  wheezing  in later childhood. [ citation needed ]


In very low birth weight infants (VLBWI), systemic fungus infection is a  hospital-acquired infection  with serious consequences. The pathogens are usually  Candida albicans  and  Candida parapsilosis . A small percentage of fungal infections are caused by  Aspergillus ,  Zygomycetes ,  Malassezia , and  Trichosporon . [ 22 ] [ 23 ]  Infection is usually late-onset. Up to 9% of VLBWI with birth weights of <1,000 g develop these fungus infections leading to sepsis or meningitis. As many as one-third of these infants can die. Candidiasis is associated with retinopathy, prematurity and negative neurodevelopmental consequences. Candida can colonize the gastrointestinal tract of low birthweight infants (LBI). This gastrointestinal colonization is often a precursor to a more serious invasive infection. The risk of serious candida infection increases when multiple factors are present. These are:  thrombocytopenia , the presence of candidal dermatitis, the use of systemic steroids, birth weights of <1,000 g, presence of a central catheter, postponing enteral feeding, vaginal delivery, and the amount of time broad-spectrum antibiotics were given. [ 23 ]


Infants born with  malaria  can be infected with a variety of  species ;  Plasmodium vivax ,  Plasmodium malariae ,  Plasmodium ovale , and  Plasmodium falciparum . In most instances of congenital malaria is caused by  P. vivax  and  P. falciparum . Women living in areas where malaria is prevalent and common are repeatedly exposed to malaria. In response to maternal infection, mothers develop antimalarial  antibodies . It is probable that the antibodies present in the mother offers protection for the baby. Bacterial infection can develop with malaria. [ 22 ]


Infants that are infected by the protozoan  Toxoplasma gondii  in utero can be born with  chorioretinitis  or ocular toxoplasmosis. Globally, it is the most common cause of infections of the back of the eye. (posterior segment). The most common sign is decreased vision in one eye. Other signs and symptoms may appear after the neonatal period and include: chorioretinitis development later in life, intracranial calcification hydrocephalus or central nervous system abnormalities. [ 24 ]


Preterm neonates are at greater risk of infection, including severe complications such as sepsis and meningitis. Preterm neonates usually have ineffective immune systems, due to decreased IgG antibodies and decreased complement activation. Additionally, preterm neonates require longer hospital admissions, including the placement of invasive devices that increase risk of infection. [ citation needed ]


Maternal risk factors for neonatal infection include:


Inflammation accompanies infection and is likely to complicate  treatment  and recovery. Inflammation is linked to reduced growth of the  lungs  of the premature baby. [ 26 ]


The recent identification of the presence of  microorganisms  in maternal-infant body fluids that were previously thought to be sterile has provided one explanation for the presence of the inflammatory response in both the mother and infant. Sixty-one percent of pregnant women with  chorioamnionitis , or inflammation of the  amniotic fluid , were found to be infected by microorganisms. Often,  more than one  pathogen was present. In fifteen percent of pregnant women inflammation was still evident even though there was no evidence of pathogens. This may indicate that there are other causes. A high percentage, 51% to 62%, of pregnant women who had chorioamnionitis also had inflammation of the  placenta . [ 26 ]


Diagnosis  of infection is based upon the recovery of the pathogen or pathogens from the typically  sterile  sites in the mother or the baby. Unfortunately, as many half of pregnant women are asymptomatic with a gonorrhea infection and other sexually transmitted infections. [ 27 ] [ 28 ] [ 29 ]  Samples are obtained from  urine ,  blood  or  cerebrospinal fluid . Diagnosis of infection can also be aided by the use of more nonspecific tests such as determining the total  white blood cell  count,  cytokine  levels and other blood tests and  signs . [ 30 ]


Symptoms and the isolation of the virus pathogen the upper respiratory tract is diagnostic. Virus identification is specific immunologic methods and PCR. The presence of the virus can be rapidly confirmed by the detection of the virus antigen. The methods and materials used for identifying the RSV virus has a specificity and sensitivity approaching 85% to 95%. Not all studies confirm this sensitivity. Antigen detection has comparatively lower sensitivity rates that approach 65% to 75%. [ 35 ]


Congential malaria has its own set of signs:


Neonatal sepsis of the newborn is an infection that has spread through the entire body. The inflammatory response to this systematic infection can be as serious as the infection itself. [ 26 ]  In infants that weigh under 1500 g,  sepsis  is the most common cause of death. Three to four percent of infants per 1000 births contract sepsis. The mortality rate from sepsis is near 25%. [ 36 ]  Infected sepsis in an infant can be identified by culturing the blood and spinal fluid and if suspected, intravenous antibiotics are usually started. Lumbar puncture is controversial because in some cases it has found not to be necessary while concurrently, without it estimates of missing up to one third of infants with meningitis is predicted. [ 30 ]


To reduce neonatal infection, screening of pregnant women for HIV, hepatitis B, and syphilis, is available in the UK and the United States. [ 37 ] [ 38 ]


Treatment with a vaginal antibiotic wash prior to birth does not prevent infection with group B streptococcus bacteria (GBS). [ 31 ] [ 39 ]  Treatment with vaginal chlorhexidine prior to birth does not prevent neonatal infections. [ 40 ]


Because GBS bacteria can colonize the lower reproductive tract of 30% of women, typically pregnant women are tested for this pathogen from 35 to 37 weeks of pregnancy. Before delivery treatment of the mother with antibiotics reduces the rate of neonatal infection. [ 31 ]  Prevention of the infection of the baby is done by treating the mother with penicillin. Since the adoption of this prophylactic treatment, infant mortality from GBS infection has decreased by 80%. [ 36 ]


Mothers with symptomatic  genital herpes  and who are treated with antiviral prophylaxis are less prone to have an active, symptomatic case at the time of birth and it may be able to reduce the risk of passing on HSV during birth. Cesarean delivery reduces the risk of infection of the infant. [ 41 ]


Breastfeeding  has been shown to protect the neonate from some infections. [ 42 ] [ 43 ] [ 44 ] [ 45 ] [ 46 ]   [ excessive citations ]  Breast milk protects against necrotizing  enterocolitis . [ 47 ]


Hepatitis A, B, and D are preventable via vaccination. Hepatitis A can be prevented by immunization against HAV, while Hepatitis B and D can both be prevented by immunization against HBV. [ 20 ]


The Hepatitis B vaccination is among the first two injections a newborn receives. [ 48 ]  The other is vitamin K to prevent  vitamin K deficiency bleeding . [ 49 ]  In cases where the pregnant woman is positive for hepatitis B, the baby will receive an additional dose of hepatitis B immunoglobulin in addition to the hepatitis B vaccine to prevent transmission of the disease from mother to baby. [ 50 ]  Prevention of hepatitis B is crucial as there is no currently no cure. [ 51 ]


In general, in an unvaccinated individual, the viral hepatitis family causes liver damage due to a cell-mediated response via cytotoxic lymphocytes. [ 52 ]  Acute viral hepatitis can lead to jaundice, elevated bilirubin, elevated liver enzymes (aspartate transaminase, alanine transaminase, and alkaline phosphatase), and flu-like symptoms. [ 52 ]  Importantly, acute neonatal HBV infections progress to chronic Hepatitis B about 90% of the time. [ 53 ]  For both Hepatitis B and Hepatitis D, the most significant long-term complications are progression to cirrhosis and hepatocellular carcinoma, which carries high morbidity and mortality. [ 54 ]


Neonatal infection treatment is typically started before the diagnosis of the cause can be confirmed.
Neonatal infection can be prophylactically treated with antibiotics. [ 55 ]  Maternal treatment with antibiotics is primarily used to protect against group B streptococcus. [ 30 ]


Women with a history of  genital herpes , can be treated with antiviral drugs to prevent symptomatic lesions and viral shedding that could infect the infant at birth. The antiviral medications used include acyclovir, penciclovir, valacyclovir, and famciclovir. Only very small amounts of the drug can be detected in the fetus. There are no increases in drug-related abnormalities in the infant that could be attributed to acyclovir. Long-term effects of antiviral medications have not been evaluated for their effects after growth and development of the child occurs. Neutropenia can be a complication of acyclovir treatment of neonatal HSV infection, but is usually transient. [ 41 ]  Treatment with immunoglobulin therapy has not been proven to be effective and is not recommended. [ 56 ]


Up to 3.3 million newborns die each year and 23.4% of these die of neonatal infection. About half of the deaths caused by sepsis or pneumonia happen in the first week postpartum. In industrialized countries, prophylactic antibiotic treatment of the mothers identified with group B streptococcus, early identification of sepsis in the newborn, and administration of antibiotics to the newborn has reduced mortality. [ 31 ]  Neonatal herpes in North America is estimated to be from 5 – 80 per 100,000 live births. HSV has a lower prevalence in mothers outside the United States. In the United Kingdom the incidence is much lower and estimated to be 1.6 per 100,000 live births. Approximately 70% to 80% of infected infants are born to mothers with no reported history of HSV infection. [ 41 ]


Regions with low neonatal mortality include Europe, the Western Pacific, and the Americas, which have sepsis rates that account for 9.1% to 15.3% of the total neonatal deaths worldwide. This is in contrast with the 22.5 to 27.2% percentage of total deaths in resource-poor countries such as Nigeria, the Democratic Republic of the Congo, India, Pakistan, and China. [ 31 ]


In the UK, the proportions of pregnant women who are newly screened positive for hepatitis B, syphilis, and HIV have remained constant since 2010 at about 0.4%, 0.14% and 0.15%, respectively. Estimated prevalence levels among pregnant women for hepatitis B and HIV, including previous diagnoses, were higher at 0.67% and 0.27%. Pregnant women evaluated as susceptible to rubella due to low antibody levels have increased by over 60%, to about 7.2%. However, this increase is probably due to changes in testing methods and evaluation criteria. [ 57 ]


In North America, prior to the 1950s, group A β-hemolytic streptococcus (GAS) was the most common pathogen associated with neonatal sepsis prior to the 1960s. In the past twenty years, the most common pathogen causing sepsis is coagulase-negative staphylococci that exist as biofilms associated with infected central venous or arterial catheters. [ 55 ]  Infections can be fatal and contribute to long-term morbidity and disability among the infants who survive into childhood. [ 55 ]  Neonatal sepsis effects 128 cases per 1000 live births. Meningitis can occur in the septic infant. [ 30 ]
Expectant mothers with HSV have a 75% chance of at least one flare-up during their pregnancy. [ 41 ]  In limited studies it was found that infants in Africa born to mothers with malaria have a 7% of acquiring congenital malaria. [ 22 ]


Early onset sepsis can occur in the first week of life. It usually is apparent on the first day after birth. This type of infection is usually acquired before the birth of the infant.  Premature rupture of membranes  and other  obstetrical complications  can add to the risk of early-onset sepsis. If the amniotic membrane has been ruptured greater than 18 hours before delivery the infant may be at more risk for this complication. Prematurity, low birth weight, chorioamnionitis, maternal urinary tract infection and/or maternal fever are complications that increase the risk for early-onset sepsis. Early onset sepsis is indicated by serious respiratory symptoms. The infant usually develops pneumonia, hypothermia, or shock. The mortality rate is 30 to 50%. [ 30 ]


Infections that occur after the first week of life but before the age of 30 days are considered late onset infections. Obstetrical and maternal complications are not typically the cause of these late onset infections; they are usually acquired by the infant in the hospital neonatal intensive care unit. The widespread use of broad-spectrum antibiotics in the nursery intensive care unit can cause a higher prevalence of invasive antibiotic resistant bacteria. [ 30 ]  Meconium aspiration syndrome has a mortality rate just over 4%. This accounts for 2% for all neonatal deaths. [ 58 ]


The susceptibility to risk of infection and immune deficiencies are active areas of research. Studies regarding the role of viruses in neonatal infections are lacking. Research also continues into the role and protective effect of gut, skin and other human microbiomes and the colonization during the neonatal period. [ 26 ] [ 30 ]  The comparison between both resource rich and poor countries makes it difficult to compare the diagnosis success; as industrialized regions are able to confirm the diagnosis and presence of pathogens in the clinical laboratory. Clinical testing may not be available in all settings and clinicians must rely on the signs of infection in the newborn. Research data from Africa and Southeast Asia is scarce. [ 31 ]


The result of some research has been the identification of diagnostic tools and procedures that could identify mothers with group B streptococcus infection in resource-poor regions. These procedures would be easy and inexpensive to use. Those mothers who are identified as being infected could then be prophylactly treated prior to the birth of the baby. [ 31 ]


Probiotic administration of Lactobacillus species has shown some success. [ 59 ]


A GBS vaccine is currently being tested but not currently available. Vaccination is estimated to being able to prevent 4% of GBS infections for preterm births and 60–70% for neonatal GBS infections in the US. The projected benefits of maternal vaccination is the prevention of 899 cases of GBS disease and 35 deaths among infants. The cost savings in the prevention of GBS may be over 43 million dollars. Vaccination may be especially beneficial in low to middle income countries where screening and prophylactic treatment is not possible. Analysts project that GBS vaccination would prevent 30–54% of infant GBS cases. Screening, prophylactic antibiotics and vaccine would prevent 48% of infection. [ 60 ]


Nesting behavior  is an  instinct  in  animals  during  reproduction  where they prepare a place with optimal conditions to nurture their  offspring . [ 1 ]  The  nesting place  provides protection against predators and competitors that mean to exploit or kill offspring. [ 2 ]  It also provides protection against the physical environment. [ 1 ]


Nest building is important in family structure [ 3 ]  and is therefore influenced by different mating behaviours and social settings. [ 4 ]  It is found in a variety of animals such as  birds ,  fish ,  mammals ,  amphibians , and  reptiles . [ 1 ]


Female  dogs  may show signs of nesting behaviour about one week before they are due [ 5 ]  that include pacing and building a nest with items from around the house such as blankets, clothing, and stuffed animals. [ 5 ]  (They also sometimes do this in cases of  false pregnancy , or pseudocyesis).  Domestic cats  often make nests by bringing straw, cloth scraps, and other soft materials to a selected nook or box; they particularly are attracted to  haylofts  as nest sites. Commercial  whelping  and queening boxes are available; however, children's wading pools (dogs) and plastic dishpans (cats) work just as well. [ 5 ]  In  birds  it is known as "going  broody ", and is characterized by the insistence to stay on the nest as much as possible, and by cessation of laying new eggs.  Marsupials  do not exhibit a nesting instinct per se, because the mother's pouch fulfills the function of housing the newborns. Nest building is performed in order to provide sufficient shelter and comfort to the arriving offspring. [ 6 ]  Threats, such as predators, that decrease the chance of survival will increase care of offspring. [ 7 ]


Under natural conditions,  sows  will leave the herd and travel up to 6.5 km (4.0 mi) [ 6 ]  a day prior to  parturition  in order to find the appropriate spot for a nest. [ 8 ]  The sows will use their forelimbs and snouts in order to create excavated depressions within the ground and to gather/transport nesting materials. [ 9 ]  Although the nests vary in radius dependent on the age of the sow, the nests are generally a round to oval shape and are usually located near trees, uprooted stumps or logs. [ 9 ]  The shelter provided by the nest built in sows is of utmost importance to  thermoregulation . For the first two weeks of the piglets life their physiological thermoregulation is still developing, and due to a lack of amount of  brown fat tissue , piglets require an increased surrounding temperature. Without the protection of the nest, the piglets will be subjected to climatic influences causing their internal temperature to drop to life-threatening levels. [ 6 ]


Farrowing crates  have been widely implemented into modern pig  husbandry  in order to reduce piglet mortality via crushing. However, this type of housing disturbs the sows natural instinct to nest build due to lack of space. Thus, it is necessary for the sows to farrow without the performance of this natural pre-partum activity which results in high stress for the animal.


In  rodents  and  lagomorphs , the nesting instinct is typically characterized by the urge to seek the lowest sheltered spot available; this is where these  mammals  give birth. Rats, for example, prefer to burrow amongst dense areas of vegetation or around human settlements which they come into contact with often. [ 10 ]  Often some rodent species create burrows that develop microclimates. This is another way that nesting instinct aids in  thermoregulation . [ 4 ]   Alzheimer's disease  in rats has been observed to impair the nesting ability, especially in females. These impairments become exaggerated with age and progression of disease. [ 3 ]


Particularly among  burrowing animals , such as  groundhogs  and  prairie dogs  nesting is used all across the burrows for uses such as insulation, bedding,  litter  chambers, transportation, comfort and various other uses. [ 11 ]   Marmot  species such as groundhogs, and  alpine marmots  nest their borrows with thick  grasses  in advance of winter, this keeps a  thermoregulated   insulated  comfortable environment for the marmots as they undergo  hibernation . [ 12 ] [ 13 ] [ 14 ]


Maternal nest-building is regulated by the hormonal actions of  estradiol ,  progesterone , and  prolactin . Given the importance of shelter to offspring survival and reproductive success, it is no wonder that a set of common hormonal signals has evolved. However, the exact timing and features of nest building vary among species, depending on endocrine and external factors.


The initial drive to perform this behavior is stimulated internally via  hormones , specifically a rise in prolactin levels. This increase is driven by an increase in  prostaglandin  and a decrease in progesterone. [ 15 ]  The second phase of nest building is driven by external stimuli, this phase is also known as the material-oriented phase. In this stage it is said that external stimuli such as the proper nest building materials must be present. Both internal and external stimuli must exist in conjunction with one another for nest building to commence. The cessation of the nest building is correlated with a rise in  oxytocin  which is the hormone responsible for the contraction of the  uterus . Shortly after this, parturition will commence. [ 6 ]


In  rabbits , nest building occurs towards the last third of pregnancy. The mother digs and builds a nest of straw and grass, which she lines with hair plucked from her body. This sequential motor pattern is produced by changes in estradiol, progesterone, and prolactin levels. Six to eight days pre- partum , high levels of estradiol and progesterone lead to a peak in digging behavior. Both estradiol and progesterone are produced and released by the  ovaries . One to three days pre-partum, straw-carrying behavior is expressed as a function of decreasing progesterone levels, maintenance of high estradiol levels, and increasing prolactin levels. This release of prolactin (from the  anterior pituitary ) is likely caused by the increase in estrogen-to-progesterone ratio. One day pre-partum to four days post-partum, hair loosening and plucking occur as a result of low progesterone and high prolactin levels, together with a decrease in  testosterone . [ 16 ]  In  house mice  and  golden hamsters , nest-building takes place earlier, at the start or middle of pregnancy. For these species, nest-building coincides with high levels of estrogen and progestin. [ 17 ] [ 18 ]


External factors also interact with hormones to influence maternal nest-building behavior. Pregnant rabbits that have been shaved will line their straw nest with available alternatives, such as male rabbit hair or synthetic hair. If given both straw and hair, mothers prefer straw during the straw-carrying period, and prefer hair during the nest-lining period. If given hair as the only material, shaved mothers collect the hair even when it is the straw-carrying period. [ 19 ]


Research on  avian  paternal behavior shows that nest-building is triggered by different stimuli in the two sexes. Unlike the case for females, male nest-building among  ring doves  depends on the behavior of the prospective mate rather than on hormonal mechanisms. Males that are castrated and injected daily with testosterone either court females or build nests, depending purely on the behavior of the female. Hence, the male avian transition from courtship to nest-building is prompted by social cues and not by changes in hormone levels. [ 20 ]


In sand goby ( Pomatoschistus minutus )  the males are the ones who build the nests. When males exhibit increased paternal care to eggs, they build nests with smaller entrances in comparison to males who provide less parental care. This helps prevent predators from entering the nest and consuming the offspring or developing eggs. [ 7 ]


Nesting behavior is also present in many invertebrates. The best known example of nesting behavior in insects is that of the domestic  honey bee . Most  bees  build nests. Solitary bees, like honey bees, make nests. However, solitary bees make individual nests for larvae and are not always in colonies. [ 21 ]  Solitary bees will burrow into the ground, dead wood and plants. [ 21 ] [ 22 ]


The  Nun of Watton  (born in the 1140s) was a young nun at  Watton Priory  in Yorkshire who, according to an account recorded by St  Aelred of Rievaulx  around 1160 [ 1 ]  in  De Quodam Miraculo Mirabili , long known as  De Sanctimoniali de Wattun , [ 2 ]  was impregnated by a young friar and miraculously cleansed of sin.


The nun was admitted to the  Gilbertine  monastery at  Watton  in the  East Riding of Yorkshire , one of the most successful monasteries of those founded by  Gilbert of Sempringham , at approximately four years of age, [ 2 ]  upon the request of  Henry Murdac , Archbishop of York. Nothing is known about her family, however, the fact that Henry took an interest in her, as well as her stature as a nun at an early age (as opposed to a lay sister) suggests that she was not from the lowest ranks of society. At this time the policy of the Gilbertines on accepting children into religious order was less strict than in many contemporary religious orders, although it became stricter later.


Aelred himself was a Cistercian, and his order took a paternalistic interest in the newly founded Gilbertine monasteries after refusing to accept responsibility for them. The Gilbertine Watton Priory was a  double monastery  with both male and female members, and was the only such house in the  diocese of York  in the twelfth century.


According to Aelred's report of the senior nuns' comments, (1110–1167) the young girl adopted into the monastery grew into a rebellious young woman. She soon made the acquaintance of a lay brother in the attached male community, meeting him when some of the brothers "to whom the care of external affairs was entrusted" [ 3 ]  entered the nunnery to do some work. One of these brothers, described by Aelred as "more comely than the others in features and more flourishing in age," captured her attraction, and after a series of discreet exchanges, they arranged to meet at night "at the sound of a stone" that the brother promised to throw onto the roof or wall of the building where she was waiting.


After two unsuccessful attempts, the two finally managed to meet. According to Aelred, "She went out a virgin of Christ, and she soon returned an adulteress," clearly indicating that their furtive relationship had been consummated following their encounter. The lovers continued to meet secretly, until eventually the other nuns became suspicious of the repeated noise of the stones thrown by the man. The senior sisters challenged the young nun, who confessed to her sins.


Aelred then goes on to describe the fury of the nuns who seized and beat the young woman in punishment for her crime. They tore her veil from her head, and were prevented only by the senior sisters from burning, flaying, and branding the young nun. She was then chained by fetters on each leg, placed in a cell, and fed with only bread and water.  Megan Cassidy-Welch  "demonstrates the diverse ways in which medieval Christian thinkers portrayed the prison as an essentially reformist and salvific space since, separated from the temptations of the outside world, prisoners had an ample opportunity to devote themselves to continuous prayer, contrition, and praise of God." [ 4 ]


The male culprit fled from Watton; however, his subsequent whereabouts were revealed by the nun. He was then tracked down by several brothers from Watton, who captured him by having one brother impersonate the culprit's lover and lure him in, while the other brothers lay in wait to attack.


After the young man was captured, the nuns, filled with religious zeal and with a desire to avenge their injured virginity, engaged in a brutal attack of the offending brother. He was taken by them, thrown down, and held while his lover stood by. She was handed an instrument, presumably a knife of some sort, and she was forced to castrate him. At this point, one of the senior sisters snatched the newly severed genitalia and thrust them into the disgraced nun's mouth. [ 5 ]


Following the castration, the young man was returned to the brothers, and the nun was put back into her prison.  Henry Murdac ,  Archbishop of York , who had brought her to the priory, then appeared to the nun in her sleep, instructing her to confess her sins and recite psalms. He returned to her again on the following night, just when the nun was about to give birth. He was accompanied by two heavenly women, who took away the baby, and cleansed the young nun's body of sin and pregnancy. This caused her chains and fetters to fall off.


The next morning, her caretakers found her healthy, clean, and distinctly not pregnant. After thorough inspection of her cell, they found no evidence of a birth at all. Additionally, the chains and fetters that had previously held her had fallen off. After Gilbert was informed of these miraculous events, he consulted Aelred before proceeding. Aelred investigated and declared the event to be a miracle after deciding that she could have been freed "neither by others nor by herself without the strength of God", and therefore it would be sacrilegious to imprison her again. Aelred fully accepted the authenticity of the events he described, and deemed the miraculous delivery of the child and the freeing of the nun from her fetters to be more important than the preceding acts of adultery and punishment. However, he was also intensely critical of the nun's fellow sisters and of Gilbert of Sempringham himself for their lack of pastoral care.


Jane Patricia Freeland 's 2006 translation of the work shows Aelred's ambivalence about the propriety of the nuns' behaviour toward their charge and her lover, and the apparent absence of pastoral care available to the hapless young woman at the centre of this case. [ 6 ]   Brian Golding 's history of the Gilbertines places the incident in its historical context. [ 5 ]  According to Barbara Hargreaves, Aelred's letter "is a redemptive narrative, written to be understood both literally and metaphorically. Aelred uses the physicality of the pregnancy itself, and the conditions of the nun’s incarceration, to bring to his reader the themes of physical and spiritual gestation and rebirth." [ 2 ]


This is a list of persons reported to have become father of a child at or after 75 years of age. These claims have not necessarily been verified.


According to a 1969 study, there is a decrease in sperm concentration as men age. The study reported that 90% of  seminiferous tubules  in men in their 20s and 30s contained  spermatids , whereas men in their 40s and 50s had spermatids in 50% of their seminiferous tubules. In the study, only 10% of seminiferous tubules from men aged > 80 years contained spermatids. [ 1 ] [ 2 ]  In a random international sample of 11,548 men confirmed to be biological fathers by DNA paternity testing, the oldest father was found to be 66 years old at the birth of his child; the ratio of DNA-confirmed versus DNA-rejected paternity tests around that age is in agreement with the notion of general male infertility greater than age 65–66. [ 3 ] [ 4 ]


Operative vaginal delivery,  also known as  assisted  or  instrumental vaginal delivery , is a  vaginal delivery  that is assisted by the use of  forceps  or a  vacuum extractor . [ 1 ]