Prenatal dental care  is the care of the  oral cavity  during fetal development. The woman’s body is subject to hormonal changes leading to several physical changes in the oral cavity during  pregnancy . Some of these changes may cause  tooth decay , erosion and periodontal health changes.


Proper dental care during pregnancy and recommended dental interventions are important to maintain health and well being of expecting mother and developing fetus. [ 1 ]  Dental treatment may be limited depending on gestational age and performed following gynecologist recommendations. [ 2 ]  Pharmacotherapy is very limited during pregnancy, due to potential negative effects during fetal development. The FDA has implemented strict guidelines to categorized prescribed drugs in order to regulate what is safe or unsafe during pregnancy. [ 3 ]


There are suggestions that pregnant women should seek dental visits to avoid any adverse effects on the mother and fetus during the period of pregnancy, but there is no evidence to support this avoidance. [ 1 ] [ 4 ]  Any dental treatment should be done with prior medical clearance of patient's gynecologist indicating treatment and drug limitations . [ 2 ]   Dental practitioners should keep the dental visit short, and minimally invasive. [ 5 ]  The use dental  local anesthetics  during pregnancy is safe; however, the type of vasoconstrictor and amount should be well regulated by the dentist. The safety of local anesthesia with a vasoconstrictor is questioned in patients having systemic conditions such as  heart disease , untreated  diabetes ,  hypertension , or  hyperthyroidism . [ 6 ]


Blood pressure  and  cardiac output  decrease in pregnant women, [ 7 ] [ 8 ]  and therefore is important to avoid potential  hypotensive  syndrome during dental treatment. This could be as a result of positioning patient in the supine position on the dental chair. [ 9 ]  It is recommended that the patient should have the right hip elevated 10 to 12 cm by placing a cushion; meaning the patient's hip position should be higher than the foot level in the second and third trimesters to relieve the pressure on the  inferior vena cava , and if necessary, the patient should be tilted 5% to 15% on her left side. If patient experiences  fatigue , weakness and  hypotension , a full left lateral position may be needed. [ 2 ]


Dental interventions during pregnancy are limited depending on time of fetal development, following gynecologist clearance. During the first trimester there is a high risk of miscarriage ad birth defects. Treatment should thus be limited to oral examinations, emergency procedures and cleaning. During the second trimester fetus is at low risk of birth defects; it is safe to perform limited to oral examinations, cleanings, restorative treatment, periodontal maintenance and minor maxillofacial surgical treatment. Lastly, during third trimester fetus is at a lower risk of birth defects; treatment is limited to oral examinations, cleanings and only emergency procedures. [ 2 ]


Periodontal procedures such as  scaling and root-planning  can positively improve the quality of life in pregnant women; during this procedure microbial activity is decreased by removing  plaque  and  calculus , and other irritants. [ 10 ]   Pyogenic granulomas  or “pregnancy tumors,” are commonly seen on the labial surface of the papilla in pregnant women. Lesions can be treated by local debridement or deep incision depending on their size, and by following adequate  oral hygiene  measures. [ 11 ]


Pregnant women may undergo routine  radiographic x-ray  images strictly only if necessary during pregnancy. Radiographs should be done with the use of a lead apron and thyroid collar at all times to avoid potential risks to the mother and  fetus . [ 12 ]


Hormonal changes during pregnancy have an effect on women's oral health during pregnancy. [ 13 ]  Good oral hygiene and seeking dental care during pregnancy is extremely important because an increase level of estrogen, human gonadotropin and progesterone; which can cause a variety of physiological changes in oral cavity. Additionally, there is an increase of thyroxine, steroids, and insulin. [ 13 ]


An increase of estrogen and progesterone levels makes pregnant women are more likely to develop pregnancy gingivitis. [ 13 ]  Pregnancy  gingivitis  is an inflammation of gum tissue due to an increase of blood flow to the gums. It is often characterized with soreness, sensitivity and bleeding of the gums. Pregnant women are often require more cleanings and prescription mouth rinses. [ 13 ]


If gingivitis is not treated pregnant individuals can develop  periodontitis.  Periodontal disease is a chronic condition caused by a bacterial infection to gum tissue and supporting structures. If left untreated it  can cause loosening of teeth, bad breath and irreversible bone loss. [ 13 ]


Increase levels of progesterone and bacteria might cause some women to experience pyogenic granuloma or more commonly known pregnancy tumors. [ 13 ]  These are lumps of overgrown gum very close to the gum line or in between teeth. Tumors are non-cancerous and disappear after pregnancy. [ 13 ]


Hormonal changes increase blood flow to gum tissue often resulting in  gingival hyperplasia  and gum bleeding while brushing and flossing.  [ 13 ]


During pregnancy women's  calcium ,  phosphate  and  saliva   pH  values decrease, leading to an alteration the composition of saliva. [ 13 ]  As acidity of saliva increases, pregnant women are more prone to  dental caries . [ 4 ]  Although teeth erosion and an increase of oral caries is not hormonal related, it is often experienced during pregnancy due to an increase intake of food and negative side effects vomiting due to morning sickness. [ 13 ]


The FDA categorized certain drugs according to their safety due to potential negative effects to fetus; these drugs are known to cause miscarriage and birth defects. They have been categorized in 5 categories and are prescribed following certain guidelines during pregnancy. [ 14 ] [ 3 ]


A - The drug has not shown an increased risk of fetal abnormalities when tested on pregnant women.


B -  The drug was used in animal studies but revealed no evidence of harm to the fetus, but there are no adequate studies to prove this conclusion in pregnant women, or studies have shown an actual adverse effect on animals, but studies in pregnant women have failed to demonstrate a risk to the fetus.


C - studies have shown an adverse effect but no studies to determine these effects in pregnant women.


D - The drug causes a risk to the fetus, but the benefits of therapy may outweigh the potential risk.


X - the product is contraindicated because fetal abnormalities were seen.


There have been suggestions that severe  periodontitis  and  tooth caries  may increase the risk of having  preterm birth  and  low birth weight , however, systemic reviews found insufficient evidence to determine if  periodontitis  or  tooth decay  can develop adverse birth outcomes. [ 15 ] [ 16 ]


Prenatal memory , also called  fetal memory , is important for the development of  memory  in humans. Many factors can impair fetal memory and its functions, primarily maternal actions.  There are multiple techniques available not only to demonstrate the existence of fetal memory but to measure it. Fetal memory is vulnerable to certain diseases so much so that exposure can permanently damage the development of the fetus and even terminate the  pregnancy  by  aborting  the fetus. Maternal nutrition and the avoidance of drugs, alcohol and other substances during all nine months of pregnancy (especially the critical period when the  nervous system  is developing) is important to the development of the fetus and its memory systems. The use of certain substances can entail long-term permanent effects on the fetus that can carry on throughout their lifespan.


There is some evidence that fetal memory may begin within the  second trimester  after  conception . [ citation needed ]  Substantial evidence for fetal memories has been found at around 30 weeks after conception. [ 1 ]  Fetal memory is important for parental recognition, and facilitates the bond between child and parents. One of the most important types of memory is that which stores information contributing to the maternal bond between infant and mother. This form of memory is important for a type of development known as  attachment . [ 2 ]  Fetal memory is thus critical to the survival of the fetus both prenatally (in the womb) and after birth as an infant.


The  Central Nervous System  (CNS) and memory in the fetus develop from the  ectoderm  following  fertilization  via a process called  neurulation . The ectoderm is the outermost layer of the  embryo . This happens towards the end of the third week of  gestation  (time period when the embryo is carried in the women's uterus) and ends with the start of the development of the  neural tube , an important structure crucial to development of the central nervous system.  Some evidence suggests memory is actually responsible for carrying out the development of the CNS during neurulation. However, much more research needs to be done on this. Fetal memory and brain development can be impaired by a number of maternal implications. Rubella, intrauterine hypoxia and hypothyroidism are some of the more researched examples. Alcohol and other substances such as hard drugs can affect this process as well. [ citation needed ]


Once neurulation is complete and has given rise to the  nervous system , fetal memory becomes responsible for a variety of tasks. One of its main functions at this point is to control breathing in the fetus.  Also noted, was its ability to control eye movement and coordination during all nine months of development.  There is evidence that these are practiced in the  womb  and carried out similarly after birth. Learning language as an infant also requires fetal memory. It is now known that the mother's voice is clearly heard from inside the womb and that the fetus can differentiate speech sounds, particularly the  phonemes  (a single segment of sound) in speech. This is evident in the baby when born, showing many signs of early language comprehension. It has also been shown that infants prefer their mother's native language after being exposed to it in the womb. Evidence also exists that the infant, when born, prefers its mother's smell from having memorized her scent as a fetus. Memory is critical for the recognition process that takes place between the mother and infant through  breastfeeding . Breast milk contains contents recognizable by the infant that they were exposed to through  amniotic fluid  (fluid that encompasses the fetus and is responsible for its nutrition in the womb) in the fetal stage. Since the baby is so dependent upon the mother, maternal nutrition also plays a large role in the infant developing healthy brain functioning; including memory function, which the infant cannot live without. Thus, fetal memory is critical to the survival and healthy development of the infant before and after birth. Many of these functions are measured through methods such as  classical conditioning ,  habituation  and exposure learning, being the most popular. [ 2 ]


There are considered to be three paradigms used to investigate fetal learning and memory. They are:  classical conditioning ,  habituation  and exposure learning. [ 3 ]


Classical conditioning is described as the pairing of a conditioned  stimulus  (CS) (such as a vibration) with an unconditioned stimulus (US) (such as a loud noise) to evoke a conditioned response (CR) (agitation). In this pairing, the vibration will be presented immediately followed by a loud noise. Initially, the presentation of the loud noise (US) would cause the unconditioned response (UR) (natural agitation) without prior classical conditioning. However, the continuous pairing of the loud noise (US) with the vibration (CS) converts the unconditioned response (UR) into a (CR) as the  fetus  learns that the presentation of a vibration will be followed by a loud noise. Eventually, the fetus will respond to the vibration (CS) without being exposed to the loud noise (US); this is when conditioning has occurred. Conditioning has been demonstrated in as few as 12-15 pairings of the vibration (CS) with the loud noise (US) in fetuses as early as 32 weeks of gestation. [ 3 ]
Another study replicated these findings. [ 2 ]


Fetuses between 32 and 39 weeks gestation were presented a pure tone (CS), which was paired with a vibroacoustic stimulus (US). A vibroacoustic stimulus is a low bass sound frequency that is felt by the fetus as a mechanical vibration. [ 4 ]  After 10-20 pairings, approximately 50% of the fetuses showed successful conditioning, unrelated to age or sex of the fetus. It is suggested that poorly prepared experimental set up, inaccurate or inappropriate response measures and unsuitable stimuli could all contribute to failed conditioning, as opposed to lack of fetal memory. [ 2 ]  Reasons for some fetuses demonstrating conditioning, while others do not, remains undetermined.


The second paradigm, habituation, is one of the most successful ways of investigating fetal memory. Habituation has been demonstrated in fetuses as early as 22 weeks and corresponds to the onset of fetal auditory abilities. [ 5 ] [ 6 ] [ 7 ] [ 8 ]  Both auditory and vibroacoustic stimulation have been used in habituation.  Vibroacoustic stimulation  is a technique involving the repetitive stimulation of the fetus, by applying a vibroacoustic stimulus (in predetermined intervals) to the abdomen of the mother. The movement and reaction of the fetus, in response to the stimulus, is recorded using  ultrasound  technology. This process is repeated until habituation, defined as a lack of response to the stimulus by the fetus, is reached. Stimulation trials continue into the  neonatal  period (first 28 days after birth) by presenting the same auditory stimulus, to test whether or not the fetus has memory of the stimulation events. A  scientific control  group of babies in the neonatal period, having not been exposed to the stimulus as a fetus, are used in neonatal trials to serve as a comparison.


Results from another recent study suggest that fetuses were able to form both short and long-term memories. [ 9 ]  This conclusion was drawn from the fact that habituation rates (number of stimuli needed to habituate) were higher in babies in the neonatal stage that had not previously undergone fetal stimulations when compared to those who had: therefore demonstrating the memory of the stimulus in its fetal stage being carried into the neonatal stage.


The final experimental technique used to investigate fetal learning and memory is exposure learning. This technique allows the experimenter a lot of control over the presentation of the stimulus and following testing. [ 2 ]  Exposure learning is the act of presenting the fetus with a stimulus, such as a television theme tune, repeatedly while in the womb and then testing recognition (learning) of that tune after birth. One experiment was conducted where fetuses were exposed to the television theme tune from the show " Neighbours " while in the womb. [ 10 ]  In the first condition of the experiment, newborns age 2–4 days who were exposed to the tune while in the womb were presented with the tune after birth. Upon hearing the tune, these newborns showed  physiological  changes, such as a decrease in heart rate. This observed change did not happen with unfamiliar tunes, or to newborns that were not exposed to the tune in the womb; so the tune had to be learned in the womb. Recognition of the tune was strong 2–4 days after birth, however, diminished after the age of 21 days without repeated exposure. [ 10 ]


A second exposure learning experiment, using the television theme tune, was conducted to determine when learning and memory could first take place  in utero . It was determined that by 30–37 weeks of gestation, fetuses previously exposed to the theme tune were more active when presented with the tune than those who had no previous experience with the tune. This demonstrates that stimulus recognition begins no earlier than 30 weeks of gestation. [ 11 ]


Overall, studies indicate that there is an ability for fetal learning and memory, and through classical conditioning, habituation and exposure learning that memory can be measured. It is important to note that certain periods in fetal development allow for different learning and memory abilities, which should be taken into consideration when determining if fetal memory exists. Auditory stimuli presented in the womb can be retained and recognized (learned) into the days following birth and that learning is specific to familiar auditory stimuli. [ 12 ] [ 13 ]  Measuring learning and memory in the fetus has only been discussed in terms of healthy pregnancies; however, many factors such as disease affect these delicate processes.


Much research and literature has shown that  endocrine , neurological and most other diseases a mother or father carries can have adverse effects on a fetus's development. [ 14 ]  The majority of the research done regarding fetal brain development, and consequently its memory after birth, has focused on one condition or state and two main diseases: intrauterine hypoxia, hypothyroidism and rubella.


Intrauterine hypoxia  is a condition or state caused by insufficient oxygen levels reaching a fetus during gestation, having detrimental effects on the development of its central nervous system (CNS). [ 15 ] [ self-published source? ]   In many cases, intrauterine hypoxia results in the death of the fetus.  Commonly known, the CNS is vital to the communication and response transmissions between the brain and all of the body parts within an organism.  Due to dysfunction in this system such things as cognitive functioning and attention capacity are impeded, resulting in a poor ability to decode or encode information and form memories. [ 16 ]  It has also been discovered that lower levels of oxygen reaching the developing fetus may, in fact, decrease the amount of  grey matter  produced within its brain [ 17 ]  and increase the amount of sulcal (referring to a sulcus: a fissure within the surface of the brain)  cerebrospinal fluid  (CSF); importantly in the  frontal lobe  and  temporal lobe , which are critical memory centers. [ 18 ]  The later point regarding sulcal CSF has been linked to  schizophrenia  (a mental disorder affecting thought processes). Grey matter is a large component of the CNS and is related to: muscle control, sensory perceptions, memory, emotions and speech; please follow this link for more information regarding the different brain structures and their effects on human function. [ 19 ]


Hypothyroidism  is a disease that may have severe, adverse effects on the brain development in a fetus.  These problems are often caused by a "passing-down" from the mother or from an external  neurotoxin  causing impaired  cognitive  ability and, in extreme cases,  mental retardation . [ 20 ]


Hypothyroidism is usually caused by an  iodine deficiency  that results in the under production of  thyroid  hormones or an underdeveloped thyroid gland with similar effects. [ 15 ]   Thyroid hormone release is regulated by a stimulating hormone called  thyrotropin  (TSH) in a normal functioning person.  In abnormal cases when there are lowered levels of thyroid hormone, TSH levels increase to compensate, thus doctors and medical researchers can measure TSH levels to predict hypothyroidism. [ 21 ]   If interested, a good explanation of this process and the consequences of abnormal levels of TSH can be found under this link. [ 22 ]   Reduced levels of thyroid hormones have many physical and cognitive implications for a fetus once fully developed.  Because of  ethical  reasons, most research has been carried out on rats and other mammals.  However, in the hypothyroid rat brain, numerous malformations were found:  reduced  myelin  of neurons in the CNS, deficiency of neurons in the  cerebral cortex , the  visual cortex  and  auditory cortex ,  hippocampus  and  cerebellum , which relate to general learning and  motor skill  acquisition. [ 23 ]


Rubella , synonymous with German measles, is a disease caused by a virus with the same name and is highly contagious.  It is often combated using preventative measures, typically through  vaccination .  For children and adults it can be overcome quite easily once vaccinated, however, if the fetus is exposed to the virus, especially during the first trimester (the first three months of pregnancy), major implications can occur. [ 24 ]


Fetal nutrition has implications for both the short term and long-term development of the brain. Due to ethical reasons, studies,  which may result in diminished physical functioning or short/long-term damage, are generally done on animals before being deemed safe for human trials.


There are two points in rodent brain development during which treatment with  choline , a neurotransmitter, produces lifelong enhancement of spatial memory.


The first point is at 12–17 days into embryo development, and the second is between 16 and 30 days after the rat has been born. Baby rats, from mothers fed a diet lacking in  choline  during these two periods of pregnancy, have poorer memory function than baby rats from mothers who received choline. Choline, when given during these critical periods, causes a major improvement in memory performance when rats are being trained in a maze. Even in older rats, these memory changes persist and can be used to easily identify which rats came from mothers that received enough choline. Supplementation with choline appears to reduce the speed at which memory declines with age. Choline before pregnancy is also related to changes in the birth, death, and migration of cells in the  hippocampus  during the development of the baby rats in the womb. Choline is also associated with the different location and shape of neurons involved in memory storage within the brain. [ 25 ]


In another study using rats, it was found that the size of the hippocampus (the central region in memory functioning) was affected by protein malnutrition. More specifically, only the CA1 region of the hippocampus seemed to demonstrate a significant reduction in size. The CA1 subsection of the hippocampus was 20% smaller in offspring from mothers who were fed a protein deficient diet while pregnant. Because the region of the hippocampus affected by protein malnutrition is so specific, global hippocampal function is not impaired, but rather just the function that would appear to be associated with the CA1. Rats with the CA1 volume deficit were found to perform poorly in a tasks requiring behavioural inhibition and accurate response timing. [ 26 ]


As both of these studies have only been done on rats, it is still unknown for certain whether the same effects of choline would be seen in humans. Further research in this area is needed. [ citation needed ]


Similarly to nutritional intake, drugs consumed by the mother during pregnancy can affect the brain development of her fetus. There has been a great deal of research concerned with the damaging effects of prenatal drug use, and how exactly this use impairs future memory functioning of the child. Research has focused on a variety of recreational drugs, primarily  alcohol ,  cocaine ,  heroin , and  methamphetamine .


Most drugs are rated by the  Food and Drug Administration  to a  pregnancy category , which is a government assessment of the risks to the fetus that drug use by the mother incurs. The pregnancy category levels (from least to most dangerous) are A, B, C, D and X and are described as follows: [ 27 ]


Alcohol is the most widely used of these drugs, and for that reason, the majority research on prenatal drug use has been focused on it. Research shows that prenatal exposure to alcohol can have many negative consequences, and is significantly associated with memory problems, attention problems and decreased cognitive functioning (mental processes involved in memory, perception, thinking etc.) for the offspring later in life. Also, it can lead to the development of alcohol-related problems in later years, such as alcohol dependence.


One study compared data about maternal drinking during pregnancy (alcohol consumption by the pregnant mother), to observations gathered about the offspring many years after birth. [ 28 ]  The mother's alcoholic drinking levels during mid pregnancy were measured via self-report measures (a questionnaire). In this  longitudinal study  (a study which measures participant changes over time through repeated measures), the offspring also reported their drinking habits at 21 years of age, and completed the Alcohol Dependence Scale (a self-report questionnaire). [ 29 ]   The results suggested that there is a significant correlation between prenatal alcohol exposure and the presence of dangerous alcohol problems at age 21. Episodic drinking (multiple drinks during drinking occasions) by the mother significantly increased subsequent Alcohol Dependence scores for their children.


One of the items on the Alcohol Dependence scale most positively related to their prenatal alcohol exposure includes "blacking out".   Blackouts  are alcohol-related  amnesia , occurring when long-term memory creation is impaired during a drinking episode, resulting in an inability to remember. The frequency of blackouts in young adults while drinking is strongly related to prenatal alcohol exposure; those exposed to alcohol as a fetus are more vulnerable to experiencing blackouts as an adult. Prenatal alcohol exposure can also lead to decreased problem solving skills and/or attention deficits. Attention deficits result in an inability to maintain focus on one task for a length of time, and being prone to distraction. [ 28 ]


Another study examined the relationship between prenatal alcohol exposure and executive functioning performance through a number of tests. [ 30 ]   Executive functions  are a group of processes that serve to regulate more basic brain functions such as memory, motor skills and attention. Patients who had been exposed prenatally to alcohol show decreased ability to hold and manipulate information in  working memory  (the memory system that is used to keep things in mind during complex tasks). Those with  Fetal Alcohol Syndrome  (FAS) and Fetal Alcohol Effects (FAE) (defects caused by a mother's alcohol consumption during pregnancy), have poor problem solving skills compared to control participants (participants that do not have either FAS or FAE). The memory tests used to assess the participants in this study included the following:


Prenatal alcohol exposure directly affects the ability to switch tasks, maintain attention as well as keep and manipulate information in working memory despite distraction.
Therefore, in almost all cases in this study, the patients with FAS or FAE had inferior performance on the tests when compared to the control group. Patterns show that longitudinal memory effects of prenatal alcohol exposure manifest themselves both directly and also indirectly through lower IQ.


Cocaine is an addictive  stimulant , and although there is not a comparable academic research base to alcohol, there are a fair number of studies which show adverse effects to memory performance after prenatal exposure. The pregnancy category level of cocaine is C, as described above.


Prenatal exposure to cocaine has also been linked to decreased cognitive functioning in school aged children, including lower scores in short-term memory assessments.  Short-term memory  is the memory system responsible for holding information in an easily accessible state for a short period of time.  One particular study examined the effects of prenatal cocaine exposure, among other factors, on cognitive ability in children. [ 31 ]  In this specific assessment, the  Stanford-Binet IV Test , an IQ test, was given to children who were exposed to cocaine in utero (before birth) as well as a control group of children (not exposed to cocaine in utero).  Overall, those children who were exposed to cocaine during pregnancy had lower scores on the Short Term Memory scale than unexposed children at all age levels, especially boys. Cocaine exposure also predicted lower IQ scores in general. [ 32 ]  Exposing prenatal offspring to cocaine can cause irreversible damage and increase developmental risks. [ 32 ]


A review of 42 follow up studies of prenatal drug exposed children suggests that cocaine affects the areas concerned with behavior problems, attention, language and cognition for children tested between 4 and 13 years of age. Specifically, short-term memory, visual spatial short-term memory (short-term memory for visual information specifically) and working memory were negatively affected in a number of studies. [ 33 ]


Prenatal exposure research is less abundant for  opiates , such as heroin. Despite this, heroin is given a pregnancy risk level of X, the highest rating.
One study suggested that children exposed to prenatal heroin performed worse in memory subscales of the  McCarthy Scales . In other words, youth who had been prenatally exposed to heroin performed worse on general cognitive tasks, including those associated with memory. [ 33 ]


Methamphetamine is another stimulant that has been demonstrated to have negative effects on the offspring of a pregnant woman, and is considered a level C pregnancy category drug.One study attempted to determine the neurotoxic effects (harm to nerve cells) of prenatal methamphetamine exposure on brain development, as well as on cognitive functioning. Children exposed to methamphetamine in utero scored lower on key measures of memory performance, including attention, verbal memory and long term spatial memory. [ citation needed ]


The reduced size of brain structures associated with memory and attention was also noted through  magnetic resonance imaging  (MRI), a process used to produce images of the brain for observation. [ 34 ]   For example, those with prenatal methamphetamine exposure had, on average, a smaller  hippocampus  (a brain structure involved in many things, including memory) than control participants. This reduction in size was correlated with poorer sustained attention (decreased ability to focus on a single task for a period of time) and delayed verbal memory (memory of words read or heard). The conclusion from this study is that prenatal methamphetamine exposure can be neurotoxic to the developing fetus brain. [ 35 ]


Products of conception , abbreviated  POC , is a medical term used for the tissue derived from the union of an  egg  and a  sperm . It encompasses  anembryonic gestation  (blighted ovum) which does not have a viable  embryo .


In the context of tissue from a  dilation and curettage , the presence of POC essentially excludes an  ectopic pregnancy .


Retained products of conception  is where products of conception remain in the uterus after  childbirth ,  medical abortion  or  miscarriage  (also known as spontaneous abortion). [ 1 ]  Miscarriage with retained products of conception is termed  delayed  when no or very little products of conception have been passed, and  incomplete  when some products have been passed but some still remain  in utero . [ 2 ] [ 3 ]


The diagnosis is based on clinical presentation, quantitative  HCG , ultrasound, and pathologic evaluation. A solid, heterogeneous, echogenic mass has a positive predictive value of 80%, but is present in only a minority of cases. A thickened endometrium of > 10 mm is usually considered abnormal, though no consensus exists on the appropriate cutoff. A cut-off of 8 mm or more has 34% positive rate, while a cut off of 14 mm or more has 85% sensitivity, 64% specificity for the diagnosis. Color Doppler flow in the endometrial canal can increased confidence in the diagnosis, though its absence does not exclude it, as 40% of cases of retained products have little or no flow. The differential in suspected cases includes uterine atony, blood clot, gestational trophoblastic disease, and normal post partum appearance of the uterus. Post partum blood clot is more common, reported in up to 24% of postpartum patients, and tends to be more hypoechoic than retained products with absent color flow on Doppler, and resolving spontaneously on follow up scans. The presence of gas raises the possibility of post partum endometritis, though this can also be seen in up to 21% of normal post pregnancy states. The normal post partum uterus is usually less than 2 cm in thickness, and continues to involute on follow up scans to 7 mm or less over time. Retained products are not uncommon, occurring in approximately 1% of all pregnancies, though it more common following abortions, either elective or spontaneous. There is significant overlap between appearance of a normal post partum uterus and retained products.  If there is no endometrial canal mass or fluid, and endometrial thickness is less than 10 mm and without increased flow, retained products are statistically unlikely. [ 4 ] [ 5 ] [ 6 ]


Recent studies indicate that the products of conception may be susceptible to pathogenic infections, [ 7 ]  including viral infections. Indeed, footprints of  JC polyomavirus  and  Merkel cell polyomavirus  have been detected in chorionic villi from females affected by spontaneous abortion as well as pregnant women. [ 8 ] [ 9 ]  Another  virus ,  BK polyomavirus  has been detected in the same tissues, but with lesser extent. [ 8 ]


According to the 2006 WHO  Frequently asked clinical questions about medical abortion , [ 10 ]  the presence of remaining products of conception in the uterus (as detected by  obstetric ultrasonography ) after a medical abortion is  not  an indication for surgical intervention (that is,  vacuum aspiration  or  dilation and curettage ). Remaining products of conception will be expelled during subsequent vaginal bleeding. Still, surgical intervention may be carried out on the woman's request, if the bleeding is heavy or prolonged, or causes  anemia , or if there is evidence of  endometritis .


In delayed miscarriage (also called missed abortion), the  Royal Women's Hospital  recommendations of management depend on the findings in ultrasonography: [ 11 ]


In incomplete miscarriage, the  Royal Women's Hospital  recommendations of management depend on the findings in ultrasonography: [ 11 ]


A  shotgun wedding  is a  wedding  arranged in response to  pregnancy  resulting from  premarital sex . [ 1 ]  The phrase comes from the figurative imagining that the relatives of the pregnant bride threaten the reluctant male groom with a  shotgun  in order to ensure that he marries the woman.


One purpose of such a wedding can be to get recourse from the man for the act of  impregnation ; another reason is trying to ensure that the child is raised by both parents. In some cases, as in early U.S. and in the  Middle East , a major objective was restoring the social  honor  of the mother. The practice is a  loophole  method of preventing the birth of  illegitimate children , or if the marriage occurs early enough in the gestation period, to conceal the fact that conception had already occurred prior to marriage.


In some societies, the  stigma  attached to  pregnancy out of wedlock  can be enormous, and coercive means (in spite of the legal defense of  undue influence ) for gaining recourse are often seen as the prospective father-in-law's "right". Often, a couple will arrange a shotgun wedding without explicit outside encouragement, and some religious groups consider it a  moral imperative  to marry in that situation. [ 2 ]


Premarital sexual relations remain  taboo  across all social strata throughout the  Arab world . In many cases,  fornication  is illegal and even a criminal offence under  Sharia law . Even when it is not, the social response can be extreme, especially against women who have lost their virginity prior to marriage.


In Arabian culture, shotgun weddings serve to obscure the fact that a baby was conceived prior to marriage. When that proves impossible, the social standing of the couple involved is irreparably damaged. Nevertheless, shotgun weddings help prevent the individuals involved, especially the women, from becoming  social pariahs .


Apart from instances of regional slang, there is no universal, specific term for "shotgun weddings" in Arabic. This is because they are not recognised as a regular social phenomenon and because a successfully conducted Middle Eastern shotgun wedding is generally unknown to the guests. In some  Persian Gulf  nations, the term "police station marriage" ( Arabic : زواج مخفر) may be the closest colloquial analogue for the concept of a "shotgun wedding". [ 3 ]


Because of the  sexual revolution  beginning in the 1960s, the concepts of love, sexuality, procreation and marriage began to separate after being intimately entangled in social consciousness for centuries. [ 12 ]  However, sexual practice had not always followed  social convention , resulting in shotgun or  Knobstick weddings .


In the  United States  and  Canada , the use of duress or violent coercion to marry is no longer common, although many anecdotal stories and folk songs record instances of such coercion in 18th- and 19th-century America and Canada. Pressure to marry immediately due to pregnancy has become less common as the stigma associated with out-of-wedlock births has declined and the number of such births has increased.  As a result, the typical, voluntary wedding during pregnancy might be more neutrally termed a  mid-pregnancy marriage . [ 17 ]   Mid-pregnancy weddings are common enough that many suppliers of both  bridal gowns  and  maternity clothing  sell wedding dresses that fit during the later stages of pregnancy. [ 17 ]


While a 2016 study suggests that couples who wed while pregnant do not necessarily have an increased risk of subsequent divorce, another study by  Duke University  from that same year demonstrated that, among whites, divorce rates increased from 19% for non-pregnant brides to 30%. [ 17 ] [ 18 ]


Signs and symptoms of pregnancy  are common, benign conditions that result from the changes to the body that occur during  pregnancy . Signs and symptoms of pregnancy typically change as pregnancy progresses, although several symptoms may be present throughout. Depending on severity, common symptoms in pregnancy can develop into  complications . Pregnancy symptoms may be categorized based on trimester as well as region of the body affected.


Many of the early signs of pregnancy will be similar to symptoms that come right before a period, and it can be hard to tell the difference. [ 1 ] [ 2 ]


Implantation bleeding is light vaginal bleeding in the first 10–14 days of pregnancy caused by the normal  implantation  of the embryo in the  uterine lining . Implantation bleeding may be confused with a regular  period . [ 3 ] [ 4 ]  Heavy vaginal bleeding in the  first trimester  or bleeding associated with pain, may be a sign of a  complication , such as a  miscarriage  or an  ectopic pregnancy , that would need to be assessed by a healthcare provider. [ 5 ]


Hormonal changes in early pregnancy can cause breast swelling and tenderness. Breast tenderness typically improves as the body adjusts to the pregnancy. [ 4 ]


Fatigue in the first trimester is common due to changes in hormones. [ 6 ] [ 7 ]


An increase in vaginal discharge is common during pregnancy due to hormonal changes. The discharge, known as leukorrhea, is usually thin and milky white. However, if the discharge changes color or consistency significantly, it is essential to consult a healthcare provider. [ 8 ]


Nausea and vomiting, known as  morning sickness , occurs in 80% of pregnant women. [ 9 ]  Although described as "morning sickness," pregnant women can experience this nausea any time of day or night. The exact cause of morning sickness remains unknown. Nausea and vomiting in pregnancy is typically mild and self-limited, resolving on its own by the 14th week of pregnancy. Other causes should also be ruled out when considering treatment. Initial treatment is typically conservative, and may include changes to diet and emotional support. For women that do not improve with initial treatment, medications, such as pyridoxine and doxylamine, may also be used. [ 9 ]  A rare form of severe nausea and vomiting known as  hyperemesis gravidarum  can occur in 1% of pregnant women and can affect fetal and maternal health. [ 10 ]


The  sleeping child  ( maghrebi Arabic :  ragued  or  bou-mergoud ), according to  Moroccan  and the wider  Maghrebian  folk belief, is a  fetus  which has been rendered dormant by  black  or  white magic  and may eventually wake up and be born after the normal  pregnancy  term. This belief, supported by the concept that God's will controls everything and that no event should be considered truly impossible, is used by local communities to deal with occasional cases of pregnancy in women with absentee husbands, a frequent situation in the modern era due to the large number of males working as immigrant labor in  Europe . This folk belief is used to dismiss an accusation of  adultery  and the consequences that such an accusation would bring.


This belief was acknowledged by traditional Islamic legislation in Morocco, and is still given as an explanation by some divorced or separated women expecting their ex-husbands to acknowledge the  paternity  of a child born up to twelve months after the separation. Article 154 of the current  Mudawana  in Moroccan law stipulates that a child born up to one year after the separation is considered as fathered by the ex-husband.


The storyline of  L'Enfant endormi  (2005), a Belgo-Moroccan movie by  Yasmine Kassari , is built around this theme.


Gestational age  is the time that has passed since the onset of the last menstruation, which generally or as standard occurs 2 weeks before the actual  fertilization .  Embryonic age , in contrast measures the actual age of the embryo or fetus from the time of fertilization. Nevertheless, menstruation has historically been the only means of estimating embryonal/fetal age, and is still the presumed measure if not else specified. However, the actual duration between last menstruation and fertilization may in fact differ from the standard 2 weeks by several days.


Thus, the first week of embryonic age is already week three counting with gestational age.


Furthermore, the number of the week is one more than the actual age of the embryo/fetus. For example, the embryo is 0 whole weeks old during the 1st week after fertilization.


The following table summarizes the various expression systems during week number x of gestation.


Gestational age: 2 weeks and 0 days until 2 weeks and 6 days old. 15–21 days from last menstruation.


Embryonic age: Week nr 1. 0 (whole) weeks old. 1–7 days from fertilization.


Gestational age: 3 weeks and 0 days until 3 weeks and 6 days old. 22–28 days from last menstruation.


Embryonic age: Week nr 2. 1 week old. 8–14 days from fertilization.


Gestational age: 4 weeks and 0 days until 4 weeks and 6 days old. 29–35 days from last menstruation.


Embryonic age: Week nr 3. 2 weeks old. 15–21 days from fertilization.


Gestational age: 5 weeks and 0 days until 5 weeks and 6 days old. 36–42 days from last menstruation.


Embryonic age: Week nr 4. 3 weeks old. 22–28 days from fertilization.


Gestational age: 6 weeks and 0 days until 6 weeks and 6 days old. 43–49 days from last menstruation.


Embryonic age: Week nr 5. 4 weeks old. 29–35 days from fertilization.


Gestational age: 7 weeks and 0 days until 7 weeks and 6 days old. 50–56 days from last menstruation.


Embryonic age: Week nr 6. 5 weeks old. 36–42 days from fertilization.


Gestational age: 8 weeks and 0 days until 8 weeks and 6 days old. 57–63 days from last menstruation.


Embryonic age: Week nr 7. 6 weeks old. 43–49 days from fertilization.


Gestational age: 9 weeks and 0 days until 11 weeks and 6 days old.


Embryonic age: 7 weeks and 0 days until 9 weeks and 6 days old.


Gestational age: 12 weeks and 0 days until 15 weeks and 6 days old.


Embryonic age: 10 weeks and 0 days until 13 weeks and 6 days old.


Gestational age: 20 weeks old.


Embryonic age: 18 weeks old.


Gestational age: 22 weeks old.


Embryonic age: 20 weeks old.


Gestational age: 24 weeks old.


Embryonic age: Week nr 25. 24 weeks old.


Gestational age: 30 weeks old.


Embryonic age: Week nr 29. 28 weeks old.


Gestational age: 34 weeks old.


Embryonic age: Week nr 33. 32 weeks old.


Gestational age: 35 and 0 days until 39 weeks and 6 days old.


Embryonic age: Weeks nr 34–38. 33–37 weeks old.


Transgender pregnancy  is the gestation of one or more  embryos  or  fetuses  by  transgender  people. This is possible for those born with  female reproductive systems . However,  transition -related treatments may impact fertility. Transgender men and  nonbinary  people who are or wish to become pregnant face social, medical, legal, and psychological concerns. As  uterus transplantations  are currently experimental, and none have successfully been performed on  trans women , they cannot become pregnant.


Pregnancy  is possible for  transgender men  who retain functioning  ovaries  and a  uterus , such as in the case of  Thomas Beatie . [ 1 ]  Regardless of prior  hormone replacement therapy  (HRT) treatments, the progression of pregnancy and birthing procedures are typically the same as those of  cisgender women . Delivery options include conventional methods such as  vaginal delivery  and  cesarean section , and patient preference should be taken into consideration in order to reduce gender dysphoric feelings associated with certain physical changes and sensations. [ 2 ]  It has been shown that historical HRT use may not negatively impact ovarian stimulation outcomes, with no significant differences in the markers of  follicular function  or  oocyte  maturity between transgender men with and without a history of testosterone use. [ 3 ]


Among the wide array of transgender-related therapies available, including surgical and medical interventions, some offer the option of preserving fertility while others may compromise one's ability to become pregnant (including  bilateral salpingo-oophorectomy  and/or total  hysterectomy ).


Exposing a fetus to high levels of exogenous testosterone  may damage an embryo or fetus , especially the urogenital system of a female fetus. [ 4 ]  This is particularly important in the  first trimester  when many pregnancies have not been discovered yet. [ 5 ]  Previous studies of pregnancies in women suggest that high levels of endogenous  androgens  are associated with reduced birth weight, although it is unclear how prior testosterone in a childbearing trans person may affect birth weight. [ 2 ]  Future pregnancies can be achieved by  oophyte banking , but the process may increase gender dysphoria or may not be accessible due to lack of insurance coverage. [ 6 ]


Additionally, patients experiencing  amenorrhea  (a common side effect of HRT) may experience additional challenges in identifying early pregnancies due to the lack of regular menstrual cycling that could indicate a pregnancy if missed, for example. [ 5 ]  For this reason, it is important for patients and healthcare practitioners to comprehensively discuss fertility goals, family planning and contraceptive options during gender-affirming care. [ 5 ]  Many trans men who had planned pregnancies were able to conceive within six months of stopping testosterone. [ 6 ]  Testosterone-induced changes to the reproductive tract may be partly or completely reversed after stopping HRT.


HRT for trans men eventually decreases fertility. Continued use of testosterone suppresses the  ovarian cycle  and  uterine cycle , which would otherwise cause  oocyte  maturation,  ovulation , and  menstruation  every month. Testosterone therapy also causes  atrophy  of the vagina and uterus. [ 7 ]  Testosterone use in trans men and other transmasculine individuals affects the ovaries, leading to an increased amount of  ovarian cysts , which is also seen in cisgender women with  PCOS . Individuals studied also displayed  follicular atresia , overgrowth of the  stroma , and the replacement of ovarian tissue with  collagen . The  uterine tubes  of many trans men studied were also closed or partially closed; normally, the uterine tubes are clear, allowing for fertilized oocytes to move to the uterus. However, observation of trans men and studies on lab mice reveal that testosterone treatment does not affect the number of available  gametes  (eggs/sex cells). [ 8 ]


In a study of American trans men, 28.3% reported that they were afraid of not being able to become pregnant because of hormone therapy. Because some trans men want to carry children, it is important for providers to discuss  fertility preservation  options with trans male clients before prescribing HRT. [ 9 ]


Despite its effects on fertility, testosterone therapy is not an effective contraceptive. Trans men and nonbinary people who take testosterone may still become pregnant even if their periods have stopped. [ 2 ] [ 10 ]  Trans men may experience  unintended pregnancy , [ 6 ] [ 9 ]  especially if they miss doses. [ 6 ]


Another important postpartum consideration for trans men is whether to resume testosterone therapy. There is currently no evidence that testosterone enters  breast milk  in a significant quantity. [ 11 ]  However, elevated testosterone levels may suppress  lactation  and healthcare guidelines have previously recommended that trans men do not undergo testosterone therapy while chestfeeding (breastfeeding). [ 12 ]  Trans men who undergo chest reconstruction surgery may maintain the ability to chestfeed. [ 13 ]


Chestfeeding  is possible for many trans men who medically transition, but it is rarely discussed by doctors who prescribe  testosterone  or complete  chest masculinization surgeries . While chestfeeding can be a dysphoric activity for some trans men and nonbinary people, some find it fulfilling and a practice that connects them to their baby. [ 14 ]


Some chest masculinization surgeries prohibit people from chestfeeding at all, but some surgeries maintain the mammary glands and just remove breast tissue. With these surgeries, the baby can have trouble latching and milk supply may be diminished. [ 15 ]  This can be bypassed with medication and support from doctors.


For people that are attempting chestfeeding without chest masculinization surgery,  Chest binding  has an effect on milk supply. Binding for years or binding unsafely for long periods of time prior to pregnancy can negatively affect  glandular tissue  and chestfeeding ability, and binding during a chestfeeding period is not recommended, as it can cause  mastitis . [ 16 ]


Special consideration of the mental health of transgender people during pregnancy is important. It has previously been shown that transgender individuals often experience higher rates of suicidality than cisgender people and lesser degrees of social support from their environment and familial relationships. [ 17 ] [ 18 ]  Relatedly, many transgender individuals experiencing pregnancy reported that choices of healthcare providers were substantially impacted by the views of the healthcare worker, and many transgender people prefer  midwifery  services rather than experience labor and delivery in a hospital.


Some individuals reported having  gender dysphoria  and feelings of isolation due to the public reception of their gender identity and drastic changes in appearance which occur during pregnancy, such as enlarged breasts. [ 19 ]  Some state feeling  disconnected or alienated  from their pregnant bodies. Both social gender dysphoria (related to perception by others) and physical gender dysphoria (perception of one's own body) can occur while a trans person is pregnant. [ 20 ] [ 21 ]


Unintended pregnancy  can also be dangerous to a trans person's mental health. According to a study of American transgender men between the ages of 18 and 45, 30.5% reported being afraid of pregnancy. [ 22 ]  Unwanted pregnancy can cause severe gender dysphoria and  suicidal ideation  in trans people. One nonbinary person who performed a  self-induced abortion  stated, [ 23 ]


[I used] blunt force to [my] abdomen. Considered drinking poison, as my insurance did not cover an abortion. Luckily, I was able to get on state insurance which did cover the procedure, so it did not come to that. I 100% would have done it. Dying was a better alternative to forced pregnancy.


According to the National Transgender Discrimination Survey,  postpartum  rates of suicide and depression in trans individuals has been found to be higher than the adult average. [ 18 ]  This may be attributed to factors such as lack of social support, discrimination, and lack of adequate healthcare practitioner training. [ 18 ]


Transgender people, including trans men and nonbinary people, are more likely than the general population to experience homelessness, food insecurity,  intimate partner violence , and adverse child experiences. All of these can impact pregnancy outcomes. Additionally, trans people experience  minority stress  and may be at higher risk of substance use than the general population. Some also report avoiding medical care or mistrusting medical professionals because of discrimination. [ 24 ]


Some trans men who carry pregnancies are subjected to  discrimination , which can include a variety of negative social, emotional, and medical experiences, as pregnancy is regarded as an exclusively feminine or female activity. Several studies indicate a lack of awareness, services, and medical assistance available to pregnant trans men. [ 19 ]  Inaccessibility to these services may lead to difficulty in finding comfortable and supportive services concerning  prenatal care , as well as an increased risk for unsafe or unhealthy practices.


Unintended pregnancies can result in transgender men or nonbinary people considering or attempting  self-induced abortion . Many transgender men report attempting a self-induced abortion because of lack of safe, effective abortion methods. [ 23 ]  Studies differ on abortion rates in trans men. Different studies report that between 12% [ 9 ]  and 21% of trans people's pregnancies end in abortions. Some trans people report choosing between abortion and  suicide  because pregnancy causes them intolerable  gender dysphoria . [ 23 ]


According to figures compiled by Medicare for Australia, one of the few national surveys as of 2020, 75 male-identified people gave birth naturally or via C-section in the country in 2016, and 40 in 2017. [ 25 ]


Pregnancy is not possible for  transgender women  as they lack a female reproductive system. As of 2019,  uterus transplantation  has not been successfully performed in transgender women. [ 26 ]  The Danish transgender painter  Lili Elbe  died in 1931 from surgical complications following an attempt at such an operation.


Uterine transplantation, or UTx, is in its infancy and is not yet publicly available. As of 2019, in cisgender women, more than 42 UTx procedures had been performed, with 12  live births  resulting from the transplanted uteri as of publication. [ 27 ]  The International Society of Uterine Transplantation (ISUTx) was established internationally in 2016, with 70 clinical doctors and scientists, and currently has 140 intercontinental delegates. [ 28 ]


In 2012,  McGill University  published the "Montreal Criteria for the Ethical Feasibility of Uterine Transplantation", a proposed set of criteria for carrying out uterine transplants, in  Transplant International . [ 29 ]  Under these criteria, and because no research has been conducted in genetic males, only a genetic female could ethically be considered a transplant recipient. The exclusion of trans women from candidacy is justified by the lack of research to determine how to conduct the surgery, rather than an inherent bar. [ 30 ]  In 2021, authors of the Montreal Criteria published a revised set of criteria in  Bioethics  with an ethical framework for consideration of genetic males' (and other genetic XY individuals') eligibility for uterine transplants. [ 31 ]


Some trans women can  induce lactation , allowing them to breastfeed babies they did not biologically birth. Practices such as medical lactation induction can simulate the changes of breasts during pregnancy and begin lactation with the assistance of medication.  [ 32 ]


Non-binary  people with a functioning female reproductive system can give birth. [ 33 ]


Nonbinary people taking testosterone to  transition  must interrupt  HRT  in order to carry the pregnancy, as testosterone is a  teratogen . [ 4 ]  Unintended pregnancies by non-binary people on testosterone therapy may be more common if they are on a low dose of testosterone. [ 6 ]  Nonbinary parents choose whether to be called "mom," "dad," or newly coined gender-neutral or nonbinary titles. [ 34 ]


Non-binary people who have written or been profiled about their experiences of pregnancy include Rory Mickelson, [ 35 ]  Braiden Schirtzinger, [ 36 ]  and Mariah MacCarthy. [ 37 ]


In 1583, an intersex person that had masculine gender expression reportedly became pregnant in  Beaumaris , Wales. [ 38 ]


In 2021,  Unicode  approved the "pregnant man" and "pregnant person"  emojis  in version 14.0, and added to Emoji 14.0. [ 39 ]


Umbilical cord compression  is the obstruction of blood flow through the  umbilical cord  secondary to pressure from an external object or misalignment of the cord itself. Cord compression happens in about one in 10 deliveries. [ 1 ]


On  cardiotocography  (CTG), umbilical cord compression can present with  variable decelerations  in fetal heart rate. [ 1 ]


Umbilical cord compression may be relieved by the mother switching to another position or through maternal hydration. Secondary treatments include  amnioinfusion . In persistent severe signs of fetal distress,  Cesarean section  may be needed.


The internal surface of the  uterus  is lined by  uterine  epithelial cells  which undergo dramatic changes during  pregnancy . The role of the uterine epithelial cells is to selectively allow the  blastocyst  to implant at a specific time (the time of implantation). All other times of the cycle, these uterine epithelial cells are refractory to blastocyst  implantation . Uterine epithelial cells have a similar structure in most species and the changes which occur in the uterine epithelial cells at the time of blastocyst implantation are also conserved among most species.


The cytoplasm of uterine epithelial cells contains typical organelles found in other cells, including a  nucleus , which is located towards the bottom of the cell with one or more prominent  nucleoli ,  mitochondria ,  golgi apparatus ,  endoplasmic reticulum , free  ribosomes ,  lysosomes ,  vesicles  and lipid droplets. [ 1 ]  Like all epithelial cells, the uterine epithelial cells lie on a  basal lamina .


The apical plasma membrane displays compositional variations that change at the time of implantation. The apical domain is specialized for the initial interaction with the embryo as well as controlling secretory and absorptive processes including  endocytosis  and  pinocytosis . The apical surface of the uterine epithelial cells is covered with  microvilli  that are under hormonal control and vary in length and number with the oestrous cycle and during pregnancy. A hormonally dependent  glycocalyx  is found outside the microvilli [ 2 ]  while the center of the microvilli consists of an  actin filament  core which is embedded into the  terminal web . [ 3 ]  The terminal web is a meshwork of actin filaments, which lies immediately below the microvilli and is important in maintaining the structural integrity of the cell surface as well as acting as a barrier to movement of cellular organelles. [ 4 ]


The lateral plasma membrane domain is responsible for cell adhesion and is believed to control the  paracellular  transport of fluid and electrolytes, that is transport of fluid between the cells. A junctional complex characterises this domain and consists of three specialized areas; the  zonula occludens (tight junction) ,  zonula adherens (adherens junction)  and  macula adherens (desmosome) . The zonula occludens and zonula adherens form a continuous belt around the cell that provides a barrier to  paracellular  transport and are thought to be important in cell-cell communication. [ 5 ]


The basal domain is essential for adhesion between the epithelium and underlying stroma as well as possible communication between these two regions. The uterine epithelial cells produce the basal lamina on which they rest. [ 6 ]  The basal lamina is composed of two regions; the  lamina lucida  that is an electron lucent layer adjacent to the basal plasma membrane and the  lamina densa  that is a closely packed network of fibers.


There are dramatic changes in the morphology and biochemical characteristics of the uterine epithelial cells in preparation for  blastocyst implantation . [ 7 ]  These features include a loss of apical  microvilli  such that the apical plasma membrane becomes flattened. [ 8 ] [ 9 ]  There is also a decrease in the amount of  glycocalyx  covering the apical surface  [ 8 ] [ 10 ]  which leads to a reduction  in the negative charge of the uterine epithelial cells. Collectively, these plasma membrane changes have been termed the  plasma membrane transformation . [ 11 ]  Changes in the lateral junctional complex are important in the regulation of fluid movement along the paracellular pathway, between the epithelial cells. [ 5 ]


During the early stages of pregnancy, prior to implantation, the  tight junction complex , which is the main regulator of paracellular flow, extends 0.4 μm down the lateral plasma membrane with little cross-linking of the tight junctional strands. [ 12 ]  At this time, the tight junctions are quite 'leaky' allowing movement of fluid and solutes between the epithelial cells. [ 5 ] [ 13 ]


At the time of implantation the tight junctions extended further down the lateral plasma membrane (1 μm) and there was a significant increase in the cross-linking of the tight junctional strands. [ 12 ]  At the time of implantation the tight junctions are electrochemically 'tighter’ and prevent the movement of fluids and electrolytes between the cells. [ 5 ] [ 13 ]  These changes were also found in ovariectomised rats treated with exogenous hormones. Animals treated with  oestrogen  displayed a picture of tight junctions similar to that seen on day 1 of pregnancy while rats treated with either  progesterone  alone or in combination with oestrogen had tight junctions with similar morphology to that seen at the time of implantation. [ 14 ]  Various components of the tight junctions regulate the selectivity of this paracellular pathway. For example, it has been shown that it is the  claudin  component of tight junctions regulates the charge selectivity of the tight junctions. [ 15 ]


At the time of  implantation  in a number of species the uterine lumen closes down, which allows uterine epithelial cells to come into contact with each other and ‘fixes’ the blastocyst in place. [ 9 ] [ 16 ]  Uterine closure involves mild generalised  oedema  and reabsorption of luminal fluid. [ 17 ]  Fluid absorption could occur through one or a combination of mechanisms; escape of uterine fluid through the cervix, which is unlikely, as this would have the potential to displace implanting  blastocysts ; [ 18 ]  endocytosis by pinopods, which develop at the time of attachment, [ 16 ] [ 19 ]  or by  transcellular  means. This is influenced by the  tight junction  molecules and ion/water channels in the apical  plasma membrane  of uterine epithelial cells.


Studies have found an increase in  claudin-4  within the  tight junctions  of uterine epithelial cells at the time of implantation [ 5 ]  and an increase in  ENaC  in the apical membrane of uterine epithelial cells. [ 20 ] [ 21 ] [ 22 ]  The increase in claudin-4 prevents the movement of Na+ ions between the cells, and the appearance of ENaC in the apical membrane allows movement of Na+ ions through the cell, from the lumen into the underlying stroma. [ 23 ]   There is also an increase in  AQP5  in the apical plasma membrane of uterine epithelial cells at time of implantation. [ 13 ] [ 24 ]  The  osmotic gradient  created by the reabsorption of Na+ ions leads to reabsorption of water through  AQP5 channels  in the apical plasma membrane, which causes the uterine epithelial cells to come into contact with each other and the blastocyst. [ 13 ] [ 24 ]


Uterine serpins   are members of the  A clade  of the  serine   protease inhibitor  ( serpin ) superfamily of  proteins  and are  encoded by  the  SERPINA14   gene .  Uterine  serpins are produced by the  endometrium  of a restricted group of  mammals  under the influence of  progesterone  or  estrogen . These proteins appear to be  inactive   protease  inhibitors and may function during  pregnancy  to  regulate immune function  or participate in  transplacental transport.


Uterine serpins were originally described in the uterine secretions of unilaterally-pregnant  sheep  as a pair of 57 kDa and 55 kDa  glycoproteins . [ 1 ]  Termed uterine milk proteins, their identification as members of the serpin superfamily was based on sequencing of the  cDNA  for the sheep gene. [ 2 ]  The  pig  uterine serpin was first identified because of its association with an iron-binding uterine protein termed uteroferrin. [ 3 ] [ 4 ]  and was originally termed uteroferrin-associated protein. [ 5 ]


The designation of uterine serpins as SERPINA14 [ 6 ]  is based on their classification as a highly-divergent group of the  α1-antitrypsin  or A clade. [ 7 ]   In other analyses, uterine serpins have been considered as a separate clade in the serpin superfamily. [ 8 ]


The uterine serpins are novel with respect to other serpins by virtue of their limited distribution among mammals.  They have been described only in species of the  Laurasiatheria  superorder of  eutherian  mammals. Among the clades in which uterine serpin genes exist are the  Cetartiodactyla  ( dolphin ,  cow ,  water buffalo , sheep,  goat , pig),  Perissodactyla  ( horse ) and some  carnivores  ( dog ,  giant panda ) [ 6 ] [ 9 ]  The uterine serpin gene is not expressed in all carnivores since the only uterine serpin identified in the  cat  is a pseudogene. [ 6 ]   Examination of completed genomes indicates that uterine serpin genes do not exist in  primates ,  mouse ,  rat ,  rabbit ,  marsupials ,  platypus ,  chicken  or  zebrafish . [ 6 ] [ 10 ]


Uterine serpins are products of the endometrial  epithelium  (Figure 1). Gene expression is limited to epithelial cells of endometrial glands. [ 11 ]   Late in pregnancy, uterine serpin protein can be found in the lumenal epithelium as well, [ 12 ]  perhaps as glandular epithelial cells move to the uterine lumen.


The major regulator of uterine serpin gene expression is progesterone. [ 6 ]   In the cow, estrogen can also increase uterine serpin gene expression. [ 13 ] [ 14 ]


In addition to expression in the endometrium, bovine uterine serpin is also expressed in the  ovary  ( follicles ,  corpus luteum , and  cumulus - oocyte  complex) and by  cotyledons  of the  placenta . [ 14 ] [ 15 ]


There are two lines of evidence to indicate that uterine serpins do not function as  protease inhibitors .  Uterine serpins from the sheep and pig are not inhibitory towards a variety of proteases. [ 2 ] [ 5 ] [ 16 ] [ 17 ]  In addition, several key amino acids in the hinge region of the reactive center loop which are important for protease inhibitory activity have not been conserved in uterine serpins. [ 6 ]  Bovine uterine serpin does inhibit  pepsin  but probably through a mechanism distinct from the prototypical mechanism used by serpins. [ 17 ]


There are two possible biological roles for uterine serpins during pregnancy.  The first is as a binding protein. Porcine uterine serpin binds non-covalently to uteroferrin in a way that stabilizes the iron-binding capacity of uteroferrin. [ 4 ]   Uteroferrin is transferred across the placenta where it gives up its iron to fetal transferrin. [ 18 ]  Ovine uterine serpin binds pregnancy-associated glycoproteins, [ 17 ]  which are inactive  aspartic proteases  secreted in large amounts by the  ungulate  placenta. [ 19 ]  Ovine uterine serpin also binds to  activin , [ 20 ]   IgM  and  IgA . [ 21 ]


Another possible role for uterine serpins is in the inhibition of immune cell proliferation during pregnancy to provide protection for the allogeneically-distinct conceptus.  In particular, sheep uterine serpin can inhibit  lymphocyte  and  natural killer cell  function in vitro and reduce natural-killer cell mediated abortion in a mouse model. [ 22 ]


A single nucleotide polymorphism at position 1269 of the bovine uterine serpin gene has been associated with productive life [ 23 ]  in cattle populations. [ 15 ]


A  zygote  ( / ˈ z aɪ ˌ ɡ oʊ t / ; from  Ancient Greek     ζυγωτός  (zygōtós)  'joined, yoked', from    ζυγοῦν  (zygoun)  'to join, to yoke') [ 1 ]  is a  eukaryotic   cell  formed by a  fertilization  event between two  gametes . The zygote's  genome  is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. The sexual fusion of haploid cells is called  karyogamy , the result of which is the formation of a  diploid cell  called the zygote or zygospore.


German zoologists  Oscar  and  Richard Hertwig  made some of the first discoveries on animal zygote formation in the late 19th century.


The zygote is the earliest pp developmental stage. In humans and most other  anisogamous  organisms, a zygote is formed when an  egg cell  and  sperm cell  come together to create a new unique organism.


The formation of a  totipotent  zygote with the potential to produce a whole organism depends on  epigenetic  reprogramming.   DNA demethylation  of the paternal  genome  in the zygote appears to be an important part of epigenetic reprogramming. [ 2 ]   In the paternal genome of the mouse, demethylation of DNA, particularly at sites of methylated cytosines, is likely a key process in establishing totipotency.  Demethylation involves the processes of  base excision repair  and possibly other DNA-repair–based mechanisms. [ 2 ]


In  human fertilization , a released ovum (a haploid secondary  oocyte  with replicate chromosome copies) and a haploid  sperm  cell ( male  gamete) combine to form a single  diploid cell  called the zygote. Once the single sperm fuses with the oocyte, the latter completes the division of the second  meiosis  forming a haploid daughter with only 23 chromosomes, almost all of the cytoplasm, and the male  pronucleus .  The other product of meiosis is the second polar body with only chromosomes but no ability to replicate or survive. In the fertilized daughter, DNA is then replicated in the two separate pronuclei derived from the sperm and ovum, making the zygote's chromosome number temporarily  4n diploid . After approximately 30 hours from the time of fertilization, a fusion of the pronuclei and immediate mitotic division produce two  2n diploid  daughter cells called  blastomeres . [ 3 ]
Between the stages of fertilization and  implantation , the developing  embryo  is sometimes termed as a  preimplantation- conceptus . This stage has also been referred to as the  pre-embryo  in legal discourses including relevance to the use of embryonic stem cells. [ 4 ]  In the US the National Institutes of Health has determined that the traditional classification of pre-implantation embryo is still correct. [ 5 ]


After fertilization, the conceptus travels down the  fallopian tube  towards the  uterus  while continuing to  divide [ 6 ]  without actually increasing in size, in a process called  cleavage . [ 7 ]  After four divisions, the conceptus consists of 16 blastomeres, and it is known as the  morula . [ 8 ]  Through the processes of compaction, cell division, and blastulation, the conceptus takes the form of the  blastocyst  by the fifth day of development, just as it approaches the site of implantation. [ 9 ]  When the blastocyst hatches from the  zona pellucida , it can implant in the endometrial lining of the uterus and begin the  gastrulation  stage of embryonic development.


The human zygote has been genetically edited in experiments designed to cure inherited diseases. [ 10 ]


In fungi, this cell may then enter meiosis or mitosis depending on the life cycle of the species. [ citation needed ]


In plants, the zygote may be  polyploid  if fertilization occurs between meiotically unreduced gametes.


In  land plants , the zygote is formed within a chamber called the  archegonium .  In seedless plants, the archegonium is usually flask-shaped, with a long hollow neck through which the sperm cell enters. As the zygote divides and grows, it does so inside the archegonium. [ citation needed ]


The zygote can divide asexually by  mitosis  to produce identical offspring. [ citation needed ]


A  Chlamydomonas  zygote contains  chloroplast DNA  (cpDNA) from both parents; such cells are generally rare, since normally cpDNA is inherited uniparentally from the mt+ mating type parent. These rare biparental zygotes allowed mapping of chloroplast genes by recombination. [ citation needed ]


101 Vagina  is a black-and-white  coffee table   photo-book  by Philip Werner, with a foreword by  Toni Childs . It was  self-published  in March 2013 in  Melbourne ,  Australia . The book contains 101 close-up  nude photos  shot in a non- provocative  way, along with an accompanying story or message written by each woman about her  vagina .


The book's photos and stories were exhibited five times in Australia in 2013, with a US and Canadian tour in 2014 taking place in six locations.


101 Vagina  was funded by  crowdsourcing  and took some two years to create. [ 1 ] [ 2 ]  Werner was initially inspired by  The Vagina Monologues  and subjects were found via  social media  after Werner publicised his objective to create a book that had both an educational and celebratory goal. [ 1 ] [ 3 ]  The models, ranging in age from 18 to 65, remain anonymous. Singer-songwriter  Toni Childs , who wrote the foreword, made contact with Werner after he initiated a  peace march  in honour of murdered  Australian Broadcasting Corporation  employee  Jill Meagher  in his  Brunswick, Victoria , neighbourhood. [ 4 ]


Speaking to  The Sydney Morning Herald  about the book, Werner commented that: "I hope it finds its way to a few young women and girls...So they see that [these pictures are] normal rather than pictures in magazines." [ 5 ]  Stories accompanying the photos discuss various themes, including ageing, pregnancy,  Brazilian waxing ,  first sexual encounter  and poor  body image . [ 6 ]


On publication  101 Vagina  received broad media coverage, including write-ups in  The Age , [ 1 ]   The Sydney Morning Herald [ 5 ]  and  La Presse  in Montreal. [ 7 ]  It was also discussed on  ABC Radio National [ 8 ]  and  2SER . [ 9 ]


101 Vagina  was presented as an exhibition on several occasions in Australia in 2013. This included being part of  The Sydney Fringe [ 10 ]  and  Melbourne Fringe Festival . [ 11 ]   In 2014, it was officially launched in the US and Canada with a series of exhibitions. The tour included Los Angeles [ 12 ]  and Laguna Beach. [ 2 ]


In Sydney, the exhibition was visited by police responding to a complaint that the images were visible from the street. [ 13 ] [ 14 ]  Images were required to be censored as part of a group exhibition at The Sydney Fringe. [ 15 ]


Babeland , until 2005 known as  Toys in Babeland , is a  sex toy  boutique offering  erotic  toys,  books  and  pornographic films .  LGBTQ-owned [ 1 ]  Babeland has an online store and four retail stores (in  Seattle ,  Brooklyn ,  and two in  Manhattan ).


Claire Cavanah  and  Rachel Venning  founded Toys in Babeland in 1993, in response to the lack of women-friendly sex shops in Seattle.  The store's name is a  spoonerism  of  Babes in Toyland , a feminist riot grrrl punk band and  Babes in Toyland , the title of a 1934  Laurel & Hardy  film.  Committed to offering information and encouragement to women who wanted to explore their  sexuality , the owners focused on selling quality sex toys in a boutique-like setting. [ 2 ]


In 1995, Toys in Babeland started its  mail order  business with a small print catalog based out of their Seattle store.  Shortly thereafter, in 1996, the Toys in Babeland website followed.  In 1998, the owners opened their second Toys in Babeland store in New York City, on the  Lower East Side  of Manhattan.  In 2003, they opened another New York store, in  SoHo . In 2005, Babeland debuted its fourth store in Los Angeles, which has since closed.  In 2008, Babeland opened a new location in  Park Slope, Brooklyn , [ 3 ]  making a total of three stores in New York City.


In 2003, Venning and Cavanah published  Sex Toys 101: The Ultimate Guide to Choosing and Using Sex Toys . [ 4 ]


In 2008, Babeland ran a promotion in which they gave away a free sex toy to anyone who voted in that November's election. [ 5 ]


In January 2010, Venning and Cavanah, in association with Jessica Vitkus, published a second book:  Moregasm: Babeland's Guide to Mind-Blowing Sex [ 6 ]


In May 2016, the Babeland stores in New York City voted to be represented by the  Retail, Wholesale and Department Store Union , becoming the first U.S. sex shops to be unionized. [ 7 ]


In August 2017, Babeland was sold to rival sex shop  Good Vibrations . [ 8 ] [ 9 ]  Babeland continues to operate as a separate brand.


Queer erotica author  Dena Hankins  worked at Babeland as Web Operations Manager from 1998 to 2006. [ 10 ]


Babeland has received numerous  awards  over the years, including a 2006  Zagat 's Survey award as "the best shopping experience in New York." [ citation needed ]   In 2014, it was voted "Best Place to Buy Sex Toys" by  The Village Voice , [ 11 ]  Voted "Best Sex Shop" of 2016 & 2017 by the  Best of Seattle 2016 Reader Poll  in  Seattle Weekly   [ 12 ] [ 13 ]


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Baubo  ( Ancient Greek : Βαυβώ) is a minor figure in  Greek mythology  who does not appear in surviving sources before the fourth century CE. [ 1 ]  A fragment from  Asclepiades of Tragilus  states that she is the wife of Dysaules, who was said to be  autochthonous , that they had two daughters — Protonoe and  Misa  — and that the couple welcomed Demeter into their house. [ 2 ] [ 3 ]


The fifth century CE Greek grammarian  Hesychius  records the name Baubo in his  lexicon , stating that she was the nurse of Demeter, and that the word means 'hollow' or 'stomach' (κοιλίαν,  koilian ), citing the fifth century BCE philosopher  Empedocles  as a source for this meaning. [ 4 ] [ 5 ]


Baubo is mentioned in an  Orphic  fragment relating to the  Elusinian mysteries . [ 6 ]  Whilst the goddess  Demeter  is at  Eleusis , mourning the loss of her daughter  Persephone  who had been abducted by  Hades , Baubo makes her laugh through an act of  Anasyrma . In other sources such as the  Homeric Hymn  to Demeter  the role of cheering Demeter up is filled by a slave named  Iambe  who does so by making jokes. [ 7 ]


In a different Orphic fragment (Fr. 49) of a hymn relating the abduction of Persephone, Baubo is the name of the mother of  Demophon  — a mortal child whom Demeter unsuccessfully attempts to turn immortal by anointing him with ambrosia and placing him nightly in the fire. In other sources Demophon is the son of the King of Eleusis,  Celeus , and his queen,  Metanira . This suggests that in fragment 49 Baubo is the queen of Eleusis. [ 8 ]  In this fragment, when Baubo sees what Demeter is doing, she cries out in fear. In response Demeter burns the child to death [ 9 ]


Baubo was worshipped along with Demeter and Persephone on  Paros [ 10 ]  Evidence from inscriptions indicates that she had cult status at Naxos and in Dion (Macedonia) as well as in Paros in connection with Demeter and Kore. [ 11 ]


The fragment which mentions Baubo's anasyrma is from an Orphic hymn and is five  hexameters  in length. [ 12 ]  It is preserved in the  Protrepticus  of  Clement of Alexandria , written in the second century CE: [ 13 ]


This said, she drew aside her robes, and showed
A sight of shame; child Iacchus was there,
And laughing, plunged his hand below her breasts.
Then smiled the goddess, in her heart she smiled,
And drank the draught from out that glancing cup. [ 14 ]


Clement presents the fragment as proof of the depravity of the  Eleusinian Mysteries  and Greek religion more generally. The context he provides for the quote is that Demeter had rested at  Eleusis  during her search for her daughter, and Baubo, treating her as a guest, had offered her food and wine. Demeter refused these due to her mourning; the rejection of hospitality was perceived as a slight by Baubo who responded by showing her genitals. [ 15 ]


M. Marcovich interprets  Iacchus ' role in these verses as simply that of an innocent child who happens to have appeared at the same moment as Baubo is attempting to amuse Demeter, and who is reaching below her breast because he is hungry and she is his nurse (Marcovich assumes the verses belong to a tradition in which Iacchus is the son of Demeter and Baubo his nurse). [ 16 ]  Baubo's actions are usually interpreted as an attempt to cheer Demeter up, rather than a response to a slight, based on the fact that this is what happens in  The Homeric Hymn to Demeter . Ralph Rosen sees the act as an attempt to cheer Demeter up specifically by mocking her, as is also the case with Iambe. [ 17 ]  Ralph Rosen notes, however, that no one would have understood this as serious, or contemptuous mockery of the goddess. [ 18 ]


Around a hundred years later  Arnobius , in his  Adversus Nationes  (5.25–29), used Clement as a source for his material on Greek and Roman religion. He also includes the Orphic quote, but the text contains substantial differences: his reporting of the lines suggests that Baubo drew a face on her abdomen and shaved her pubic hair. These differences in Arnobius have been attributed by Marcovich to an unknown editor who misunderstood and redacted the text that Arnobius used, rather than to Arnobius himself. [ 19 ]


The Christian historian and polemicist  Eusebius  also recorded the fragment in his  Praeparatio evangelica  (2.3.30–5), written the early fourth century CE. The entirety of book two chapter three is a quote from Clement's  Protrepticus . His quote does not contain the deviations found in Arnobius.


It is very likely that, as with the myth of Iambe, the story of Baubo is an  etiological myth  explaining certain rites and rituals of the Eleusinian Mysteries. [ 20 ]


The name Baubo is given to several different types of figurine, most of them terracotta. [ 21 ]  The oldest type of figurine given this label is the Priene type, so named because of examples found at the Sanctuary of Demeter and Kore at  Priene . These date from the third to second century BCE and depict the naked lower part of a female body with a face where the abdomen should be, with the curve of the chin merging into the  vulva . The arms are placed at ear level and carry attributes (torches, lyre, basket of fruit carried on the head). [ 22 ]  These were probably votive offerings, and were made locally. [ 22 ]


The second type of Baubo figurine comes from Egypt, and is split into two groups. The first group depicts a woman seating frontally on a large pig, whilst holding a musical instrument. In some of these figurines her right hand is touching her genitalia. The second group depicts a woman crouching on the ground, holding her legs apart. The genitalia are always very apparent. Many of them were used as amulets [ 22 ]


Elements that appear on some of the figurines of this type, such as a lotus crown and  sistrum , along with the fact that they were produced in Egypt, has led scholars to suggest that these are votive offerings to Isis from women asking for fertility or from pregnant women wanting to give birth soon. [ 22 ]  Thus, despite the name, there is no reason to assume that these figures are supposed to depict the Baubo from Greek myth, though the connection cannot be ruled out. [ 23 ]


The  Beate Uhse Erotic Museum  ( German :  Beate Uhse Erotik-Museum ) (1996 – 2014) was a  sex museum  in the  Charlottenburg  district of  Berlin ,  Germany .


The museum was opened in 1996 near  Berlin Zoologischer Garten station  by  Beate Uhse , the early stunt  pilot  and  entrepreneur , who in 1962 started the world's first  sex shop . The collection features historic Asian and European  erotic art  including several lithographs by  Heinrich Zille  as well as early  pornographic films . It claims to be "the world's largest erotic museum".


The museum was closed in September 2014. [ 1 ] [ 2 ]  Initially the museum was looking for new premises, but due to the market development in Berlin the museum never reopened. For the exhibits, a loss in value of €1.2 million was recorded in the 2015 annual report. [ 3 ]


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This article about a museum in Germany is a  stub . You can help Wikipedia by  expanding it .


This article about a Berlin building or structure is a  stub . You can help Wikipedia by  expanding it .


Butch  is a  lesbian  who exhibits a  masculine  identity or  gender presentation . [ 1 ] [ 2 ]


Since the lesbian subculture of 1940s America, "butch" has been present as a way for lesbians to circumvent traditional  gender roles  of women in society and distinguish their masculine attributes and characteristics from feminine women. [ a ]


Starting in the 1940s and 1950s, butch became a central identity in the lesbian community. [ 5 ]  It was often understood in conjunction with  femme  identity, and  butch-femme  relations have been studied at great length. [ 6 ]  As a result, butch identity on its own remains somewhat ill-defined. [ 6 ]  Butch people are often described as sexually  dominant  lesbians who are interested in having sex with femmes. [ 6 ]   The Queen's Vernacular  claimed a butch was "a lesbian with  masculine  characteristics." [ 7 ]  In  Of Catamites and Kings , Rubin describes a butch as those lesbians who use masculine mannerisms, and/or who wear traditionally male clothing, and/or who experience  gender dysphoria . [ 8 ]  The defining characteristic that most scholars agree on is that butch people are lesbians who are to some degree aligned with masculine traits.


In the mid 20th century, butch people were usually limited to a few jobs, such as factory work and cab driving, that had no dress codes for women. [ 9 ]  During the 1950s with the anti-gay politics of the  McCarthy era , there was an increase in violent attacks on gay and bisexual women, while at the same time the increasingly strong and defiant bar culture became more willing to respond with force. [ citation needed ]  Although  femmes  also fought back, it became primarily the role of butches to defend against attacks and hold the bars as gay women's space. [ 10 ]  The prevailing butch image was severe but gentle, while it became increasingly tough and aggressive as violent confrontation became a fact of life. [ 11 ]   Leslie Feinberg's  novel  Stone Butch Blues  is a predominant piece of butch literature, and offers a window into butch bar culture,  police brutality  towards  transvestites  (both drag queens and butch people), and butch  eroticism  in the 1970s. [ 12 ]


One of the subcategories of the butch identity was and is people who experience gender dysphoria. [ 8 ]  In the mid 20th century, butch was a group that included most lesbians who identified with masculine characteristics; unsurprisingly, this was a space that included many  transmasculine  identities. [ 13 ]  In the words of butch, transgender man S. Bear Bergman, "butch and transgender are the same thing with different names, except that butch is not a trans identity, unless it is." [ 14 ]  However, there is something of a "border war" between butch and  FTM  identities, as renowned butch scholar  Jack Halberstam  put it in  Transgender Butch. [ 13 ]  Some butch people identify as women and undergo some amount of  medical transition , and some FTM individuals identify as butch men. [ 15 ]  The difference between the two groups is nuanced and has as many interpretations as there are butch people. [ 8 ]  Halberstam argues that in "making concrete distinctions between butch women and transsexual males, all too often such distinctions serve the cause of heteronormativity." [ 15 ]


Butch  and  femme  ( / f ɛ m / ;  French:   [fam] ; [ 1 ] [ 2 ]  from  French     femme  'woman') [ 3 ]  are  masculine  (butch) or  feminine  (femme) identities in the  lesbian  subculture [ 4 ]  that have associated traits, behaviors, styles, self-perception, and so on. [ 5 ] [ 6 ]  This concept has been called a "way to organize sexual relationships and gender and sexual identity". [ 7 ]   Butch – femme  culture is not the sole form of a lesbian  dyadic  system, as there are many women in butch–butch and femme–femme relationships. [ 8 ]


Both the expression of individual lesbians of butch and femme identities and the relationship of the lesbian community in general to the notion of butch and femme as an organizing principle for sexual relations varied over the course of the 20th century. [ 9 ]  Some  lesbian feminists  have argued that butch–femme is a replication of  heterosexual  relations, while other commentators argue that, while it resonates with heterosexual patterns of relating, butch–femme simultaneously challenges it. [ 10 ]  Research in the 1990s in the United States showed that "95% of lesbians are familiar with butch/femme codes and can rate themselves or others in terms of those codes, and yet the same percentage feels that butch/femme was 'unimportant in their lives ' ". [ 11 ]


The word  femme  is taken from the  French  word for woman. The word  butch , meaning "masculine", may have been coined by abbreviating the word  butcher , as first noted in George Cassidy's nickname,  Butch Cassidy . [ 12 ]  However, the exact origin of the word is still unknown.


Butch artist Daddy Rhon Drinkwater created a symbol of a black triangle intersecting a red circle to represent butch/femme "passion and love". [ 13 ]  The symbol was first used on their website  Butch-Femme.com [ 14 ]  (the website is now defunct).


There is debate about to whom the terms butch and femme can apply, and particularly whether transgender individuals can be identified in this way. For example,  Jack Halberstam  argues that  transgender men  cannot be considered butch, since it constitutes a conflation of  maleness  with butchness. Halberstam further argues that butch–femme is uniquely geared to work in lesbian relationships. [ 15 ]  Stereotypes and definitions of butch and femme vary greatly, even within tight-knit  LGBTQ  communities.  Jewelle Gomez  mused that butch and femme women in the earlier twentieth century may have been expressing their closeted transgender identity. [ 16 ] [ 17 ]   Antipathy  toward female butches and male femmes has been interpreted by some commentators as  transphobia , [ 18 ]  although female butches and male femmes are not always  transgender , and indeed some heterosexuals of both genders display these attributes. [ 19 ] [ 20 ]


Scholars such as  Judith Butler  and  Anne Fausto-Sterling  suggest that butch and femme are not attempts to take up "traditional" gender roles. Instead, they argue that gender is socially and historically constructed, rather than essential, "natural", or biological. The femme lesbian historian  Joan Nestle  argues that femme and butch may be seen as distinct genders in and of themselves. [ 21 ]


"Butch" can be used as an adjective or a noun [ 22 ]  to describe an individual's  gender performance . [ 23 ]  The term butch tends to denote a degree of masculinity displayed by a female individual beyond what would be considered typical of a  tomboy . It is not uncommon for women with a butch appearance to face harassment or violence. [ 24 ]  A 1990s survey of butches showed that 50% were primarily attracted to femmes, while 25% reported being usually attracted to other butches. [ 25 ]  Feminist scholar  Sally Rowena Munt  described butches as "the recognizable public form of lesbianism" and an outlaw figure within lesbian culture. [ 26 ]  In the novel  Stone Butch Blues , author  Leslie Feinberg  explored the working-class roots in America and the concept of  transmasculine  and  stone butches . [ 27 ]  A stone butch is a " top " who does not want to be touched during sex. [ 28 ]


BUTCH Voices, a national conference for "individuals who are  masculine of center ," including  gender variant , was founded in 2008. [ 29 ] [ 30 ]


Like the term "butch," femme can be used as an adjective or a noun. [ 22 ]  Femmes are not "read" as lesbians unless they are with a butch partner, because they conform to traditional standards of femininity. Because they do not express masculine qualities, femmes were particularly vexing to sexologists and psychoanalysts who wanted to argue that all lesbians wished to be men. [ 31 ]  Traditionally, the femme in a butch–femme couple was expected to act as a stereotypical feminine woman and provide emotional support for her butch partner.  In the first half of the twentieth century, when butch–femme gender roles were constrained to the underground bar scene, femmes were considered invisible without a butch partner – that is, they could  pass as  straight because of their gender  conformity . [ 32 ]   However,  Joan Nestle  asserts that femmes in a butch–femme couple make both the butch and the femme exceedingly visible.  By daring to be publicly attracted to butch women, femmes reflected their own sexual difference and made the butch a known subject of desire. [ 33 ]


The  separatist feminist  movement of the late 1960s and 1970s forced butches and femmes underground, as radical lesbian feminists found lesbian gender roles to be a disappointing and oppressive replication of heterosexual lifestyle. [ 34 ]  However, the 1980s saw a resurgence of butch and femme gender roles.  In this new configuration of butch and femme, it was acceptable, even desirable, to have femme–femme sexual and romantic pairings. Femmes gained value as their own lesbian gender, making it possible to exist separately from butches.  For example,  Susie Bright , the founder of  On Our Backs , the first lesbian sex periodical of its kind, identifies as femme. [ 35 ]  Beyond depictions in pornography, the neo-butch and neo-femme aesthetic in day-to-day life helped add a sense of visual identity to lesbians who had abandoned these roles in the name of political correctness. [ 36 ]


In "Negotiating Dyke Femininity," lesbian scholar  Wendy Somerson  explains that women in the lesbian community who are more feminine and do not fit into the "butch" stereotype can pass as straight. She believes the link between appearance and gender performance and one's sexuality should be disrupted, because the way someone looks should not define their sexuality. In her article, Somerson also clearly talks about how within the lesbian community some are considered more masculine than others. [ 37 ]


Femmes still combat the invisibility their presentation creates and assert their sexuality through their femininity. [ 38 ]  The dismissal of femmes as illegitimate or invisible also happens within the LGBT community itself, which creates the push for femmes to self-advocate as an empowered identity not inherently tied to butches. [ 39 ]


The term "kiki" came into existence in the 1940s to describe a lesbian who did not identify as either butch or femme, and was used disparagingly. [ 40 ] [ 41 ] [ 42 ]


Labels have been tailored to be more descriptive of an individual's characteristics, such as "hard butch," "gym queen," "tomboy femme," and "soft stud." " Lipstick lesbians " are feminine lesbians. A butch woman may be described as a " dyke ," "stone butch," "diesel dyke," [ 43 ]  "bulldyke," "bull bitch," or "bulldagger." [ 44 ]  A woman who likes to receive and not give sexually is called a "pillow queen," or a "pillow princess." [ 45 ]


A "stud" is a dominant lesbian in the LGBT community. The term originated with  construction  and  animal breeding , before being associated with promiscuous or  attractive  men. [ 46 ]  The word made its way into AAVE through jive in the 1940s.  [ 47 ] [ 48 ]  The African-American lesbian community then adopted the word, meaning " masculine African-American lesbian ." [ 49 ] [ 50 ]  Studs tend to be influenced by urban and  hip-hop  cultures. [ citation needed ]  In the  New York City  lesbian community, a butch may identify herself as AG (aggressive) or as a stud. [ citation needed ]  In 2005, filmmaker  Daniel Peddle  chronicled the lives of AGs in his documentary  The Aggressives , following six women who went to lengths like  binding their breasts  to pass as men. But Peddle says that today, very young lesbians of color in New York are creating a new, insular scene that is largely cut off from the rest of the gay and lesbian community: "A lot of it has to do with this kind of pressure to articulate and express your masculinity within the confines of the hip-hop paradigm." [ 51 ]  Black lesbian filmmaker  Dee Rees  represented the AG culture in her 2011 film  Pariah . [ 52 ]


There is also an emerging usage of the terms  soft butch , "stem" (stud-femme), "futch" (feminine butch), [ 53 ]  or "chapstick lesbian" as terms for women who have characteristics of both butch and femme. Lesbians who are neither butch nor femme are called "androgynous" or "andros." [ 43 ]  The term  boi  is typically used by younger LGBT women. Defining the difference between a butch and a boi, one boi told a reporter: "that sense of play – that's a big difference from being a butch. To me, butch is like an adult...You're the man of the house." [ 54 ]  Comedian  Elvira Kurt  contributed the term "fellagirly" as a description for LGBT women who are not strictly either femme or butch, but a combination. [ citation needed ]


Those who identify as butch and femme today often use the words to define their presentation and gender identity rather than strictly the role they play in a relationship, and in a departure from the historic norm, not all butches are attracted exclusively to femmes and not all femmes are exclusively attracted to butches. Besides the terms "butch" and "femme," there are a number of other terms used to describe the dress codes, the sexual behaviours, and/or the gender identities of the sexual subcultures who use them. The meanings of these terms vary and can evolve over time.