In 2003, "persistent genital arousal" was considered for inclusion with regard to the International Consultation on Sexual Medicine (ICSM). In 2009, "persistent genital arousal dysfunction" was included in its third edition. [ 4 ]  PGAD is not included in the  Diagnostic and Statistical Manual of Mental Disorders  ( DSM-5 ) or the  International Classification of Diseases  ( ICD-10 ), which may be due to the disorder requiring further research. [ 4 ]


The condition has been characterized by a researcher as being a term with no scientific basis. [ 8 ]  There is concern that the title may be misleading because, since the genital arousal is unwanted, it is dubious to characterize it as arousal. [ 8 ]


Other researchers have suggested that the disorder be renamed "persistent genital  vasocongestion  disorder (PGVD)" [ 9 ]  or "restless genital syndrome (ReGS)." [ 9 ] [ 10 ]


Physical arousal caused by PGAD can be very intense and persist for extended periods, days, weeks or years at a time. [ 3 ] [ 4 ]  Symptoms may include pressure, pain, vibrating, pleasure, irritation,  clitoral  or penile [ 5 ]  tingling, throbbing, vaginal congestion, vaginal contractions, penile spasms, arousal, clitoral or penile erections, and prolonged spontaneous orgasms. [ 3 ]  Pressure, pleasure, discomfort, pounding, pulsating, throbbing or engorgement may include the clitoris, penis,  labia ,  vagina ,  perineum , or the  anus . [ 11 ]  The symptoms may result from sexual activity or from no identified stimulus, and are not relieved by a single orgasm; instead, multiple strong orgasms over hours, days, or weeks are needed for short term relief. [ 4 ]   The symptoms can impede home or work life. [ 3 ] [ 9 ]   Women and men [ 5 ]  may feel embarrassment or shame, and avoid sexual relationships, because of the disorder. [ 3 ] [ 4 ]  Stress can make the symptoms worse. [ 9 ] [ 11 ]


Researchers do not know the cause of PGAD, but assume that it has  neurological ,  vascular ,  pharmacological , and  psychological  causes. [ 1 ] [ 4 ]   Tarlov cysts  have been speculated as a cause. [ 3 ] [ 11 ]  PGAD has been associated with  clitoral priapism , [ 12 ]  and has been compared to priapism in men. [ 6 ] [ 7 ]  It is also similar to  vulvodynia , in that the causes for both are not well understood, both last for a long time, and women with either condition may be told that it is psychological rather than physical. [ 3 ]  It has been additionally associated with  restless legs syndrome  (RLS), but only in a minority of women, [ 9 ]  as well as men.


In some recorded cases, the syndrome was caused by or can cause a pelvic arterial-venous malformation with arterial branches to the  clitoris. [ 11 ] [ 13 ]  Surgical treatment was effective in this instance. [ 13 ]  There is evidence that some drugs such as SSRIs and SNRIs might induce or worsen PGAD. [ 14 ]


The following five criteria must be met by patients in order to be diagnosed with PGAD: [ 15 ] [ 16 ]


Because PGAD has only been researched since 2001, there is little documenting what may cure or remedy the disorder. [ 4 ]  Treatment may include extensive  psychotherapy , psycho-education, and pelvic floor physical therapy. [ 4 ] [ 9 ]  In one case, serendipitous relief of symptoms was concluded from treatment with  varenicline , a treatment for  nicotine  addiction. [ 4 ]  It was reported in a study that repeated masturbation (51%), strong or prolonged orgasms (50%), distraction (39%), intercourse (36%), exercise (25%), and cold compresses (13%) were the most relieving treatments that could be done without the help of a professional. [ 17 ]


Having a team of professionals such as a medical provider, a pelvic floor physical therapist, massage therapist and sex therapist has been shown to aid patients. One study found that, after working with professionals, patients felt validated, listened to, and that their sexual function had improved. [ 15 ]  Many patients felt practicing mindfulness allowed them to adjust to living with PGAD by recognizing thoughts and emotions corresponding to the symptoms and avoiding brooding over them. [ 17 ]  This treatment method focuses on reducing the anxiety that is caused by the condition and pushes the patient to develop effective distraction and relaxation techniques. [ 16 ]


PGAD is very rare and is believed to affect about 1% of women; [ 15 ]  it is considered even rarer in men. [ 5 ]  Although online surveys have indicated that hundreds of women and men [ 5 ]  may have PGAD, [ 4 ]  documented case studies have been limited. [ 18 ] [ 19 ] [ 20 ]


The earliest references to PGAD may be Greek descriptions of  hypersexuality  (previously known as "satyriasis" and "nymphomania"), which confused persistent genital arousal with sexual insatiability. [ 4 ]  While PGAD involves the absence of sexual desire, hypersexuality is characterized as heightened sexual desire. [ 1 ] [ 4 ]


The term  persistent sexual arousal syndrome  was coined by researchers Leiblum and Nathan in 2001. [ 1 ] [ 3 ]  In 2006, Leiblum renamed the condition to "persistent genital arousal disorder" to indicate that genital arousal sensations are different from those that result from true sexual arousal. [ 1 ]  The rename was also considered to give the condition a better chance of being classified as a dysfunction. [ 1 ]  Now PGAD is often called or termed Genito-Pelvic Dysesthesia. [ 21 ]


Women and men [ 21 ]  with PGAD report having unstable mental health with thoughts of suicide and difficulty completing daily activities. [ 22 ] [ 23 ]  Most people that suffer from PGAD report having to masturbate 6, 20 or even more times a day and may have to use many types of sexual devices to experience any type of relief from symptoms. [ 24 ]  Many people are afraid to leave their homes due to fears that PGAD symptoms may flare up while in public and they will not be able to wait until they are able to relieve themselves. [ 24 ]


Before the start of their PGAD, many women were seen to have higher stress scores as well as symptoms of depression and anxiety. [ 23 ]  Panic attacks (31.6%) and major depression (57.9%) were reported commonalities between patients occurring at least one year prior to the onset of PGAD symptoms. Up to 45% of women and men with the disorder have reported having a history with antidepressants. [ 17 ] [ 21 ]


A small study found that several women and men began to see symptoms of PGAD after discontinuing the use of their  selective serotonin reuptake inhibitors . [ 21 ]  It is not known whether reintroduction of the SSRIs would improve PGAD symptoms. [ 22 ]


Pupillary response  is a  physiological  response that varies the  size of the pupil , via the  optic  and  oculomotor  cranial nerve.


A  constriction response  ( miosis ), [ 1 ]  is the narrowing of the pupil, which may be caused by scleral buckles or drugs such as  opiates / opioids  or anti-hypertension medications. Constriction of the pupil occurs when the  circular muscle , controlled by the  parasympathetic nervous system  (PSNS), contracts, and also to an extent when the  radial muscle  relaxes.


A  dilation response  ( mydriasis ), is the widening of the pupil and may be caused by  adrenaline ;  anticholinergic  agents;  stimulant  drugs such as  MDMA ,  cocaine , and  amphetamines ; and some  hallucinogenics  (e.g.  LSD ). [ 2 ]  Dilation of the pupil occurs when the smooth cells of the  radial muscle , controlled by the sympathetic nervous system (SNS), contract, and also when the cells of the iris sphincter muscle relax.


The responses can have a variety of causes, from an  involuntary reflex reaction  to exposure or inexposure to light—in low light conditions a dilated pupil lets more light into the eye—or it may indicate  interest  in the subject of attention or  arousal ,  sexual stimulation , [ 3 ]   uncertainty , [ 4 ]  decision conflict, [ 5 ]  errors, [ 6 ]  physical activity [ 7 ]  or increasing  cognitive load [ 8 ]  or demand. The responses correlate strongly with activity in the  locus coeruleus   neurotransmitter  system. [ 9 ] [ 10 ] [ 11 ]  The pupils contract immediately before  REM sleep  begins. [ 12 ]  A pupillary response can be intentionally  conditioned  as a Pavlovian response to some stimuli. [ 13 ]


Some humans have the ability to exert direct and voluntary control over their  iris sphincter muscles  and  dilator muscles , granting them the ability to dilate and constrict their pupils on command, regardless of lighting condition and/or eye  accommodation  state. [ 14 ]  However, this ability is very rare, and its potential use or advantages are unclear.


The  latency  of pupillary response (the time in which it takes to occur) increases with age. [ 15 ]


In  ophthalmology , intensive studies of pupillary response are conducted via videopupillometry. [ 16 ]


Anisocoria  is the condition of one pupil being more dilated than the other.


Sensation play , also known as  sensual play  or  sensory play , is an act where senses are engaged in various ways to heighten  erotic  pleasure and induce  sensuality . As an activity, it is meant to impart pleasurable and  arousing  sensations upon a partner, usually during an  intimate  interaction. [ 2 ]


As opposed to mental forms of erotic play such as  power exchange  or  sexual roleplaying , a sensual play is generally pleasing and light, that deliberately engages the  five senses  to explore pleasure, thereby leading to intense sexual arousal or  orgasm . [ 3 ]


Sensation play  can be an  umbrella term , with the harsher " pain play " and gentler "general sensory play" being subtypes, where an individual may prefer one or the other. [ 3 ]


Many couples that would not consider themselves active in  BDSM  are familiar with sensual play: the use of silk scarves, feathers, blindfolding, tickling,  erotic music , ice,  massage oils , soft  spanking , and other similar implements. The sensation can come from just about anywhere, provided that the implement falls within the negotiated terms of the interaction or  relationship . Sensation play is meant to give arousing sensations to a partner's body. It is limited only by one's own  imagination  and a lot of variation can occur from one play scene to the next. [ 3 ]


Unlike BDSM, sensual play is soft and, according to Dr Celina Criss, "Pain never needs to be involved in sensual sensory play...Think gentle touches, delicious  flavors , delightful  scents , different kinds of light, and beautiful  soundtracks . The clothes we wear and the settings we create can be a big part of this sort of play." [ 3 ]  Other examples in sensual play include hand holding, talking dirty, a person's fingers running through their hair, and as well as the partner's scent, which can emphasize sexual arousal. [ 4 ]


Sensation play in  BDSM  can also involve  sadomasochistic  play or "pain play", involving the application of  carefully controlled  stimuli to the human body so that it reacts as if it were actually hurt. While this can involve the infliction of actual  pain , it is usually done in order to release pleasurable  endorphins , creating a sensation somewhat like  runner's high  or the afterglow of  orgasm . In BDSM play, the dom (or  dominant ) introduces and controls the sensation to the sub (or  submissive ). [ 5 ]


Note that safety and consent are of paramount importance in the practice of more intense forms of sensation play. People engaging in such activities should adhere to the principles of " safe, sane and consensual " or of " risk-aware consensual kink ".


Sensual play acts range from light to gentle, such as:


To more pain-inducing or hazardous interactions:


The  Motion Picture Association film rating system  uses the descriptor "sensuality" for films that exhibit some  erotically suggestive  images or scenes. [ 10 ] [ 11 ]  The usage of "sensuality" has been met with some criticism because audiences confuse it with " sexuality ", another common descriptor in movie ratings. [ 12 ]


Sexual concordance  refers to the degree of  correlation  between subjective  sexual arousal  and physiological  genital  response. [ 1 ] [ 2 ]  This phenomenon is often studied within the fields of  sexology  and  psychology  to understand the complex relationship between the mind and body during  sexual activity .


Sexual concordance examines how closely an individual's reported feelings of sexual arousal align with measurable physical signs of arousal, such as genital blood flow. Research indicates that there is often a significant difference between subjective and physiological sexual arousal, which can vary based on factors such as gender, sexual orientation, and individual properties. Such difference is called  arousal non-concordance .


Sexual arousal can be measured through various subjective and objective methods:


Research has found differing patterns of sexual concordance among different groups:


Several hypotheses have been proposed to explain the phenomenon of sexual concordance and its greater variability in women compared to men:


Sexual arousal


Sexual dysfunction  is difficulty experienced by an individual or partners during any stage of normal  sexual activity , including physical pleasure,  desire , preference,  arousal , or  orgasm . The  World Health Organization  defines sexual dysfunction as a "person's inability to participate in a sexual relationship as they would wish". [ 1 ]  This definition is broad and is subject to many interpretations. [ 2 ]  A diagnosis of sexual dysfunction under the  DSM-5  requires a person to feel extreme distress and  interpersonal  strain for a minimum of six months (except for substance- or medication-induced sexual dysfunction). Sexual dysfunction can have a profound impact on an individual's perceived quality of sexual life. [ 3 ]  The term  sexual disorder  may not only refer to physical sexual dysfunction, but to  paraphilias  as well; this is sometimes termed  disorder of sexual preference .


A thorough sexual history and assessment of general health and other sexual problems (if any) are important when assessing sexual dysfunction, because it is usually correlated with other psychiatric issues, such as mood disorders, eating and anxiety disorders, and schizophrenia. [ 4 ] [ 5 ] [ 2 ]  Assessing performance anxiety,  guilt ,  stress , and  worry  are integral to the optimal management of sexual dysfunction. Many of the sexual dysfunctions that are defined are based on the  human sexual response cycle  proposed by  William H. Masters and Virginia E. Johnson , and modified by  Helen Singer Kaplan .


Sexual dysfunction can be classified into four categories:  sexual desire disorders ,  arousal disorders ,  orgasm disorders , and  pain disorders . Dysfunction among men and women are studied in the fields of  andrology  and  gynecology  respectively. [ 6 ]


Sexual desire  disorders or decreased  libido  are characterized by a lack of  sexual desire ,  libido  for  sexual activity , or  sexual fantasies  for some time. The condition ranges from a general lack of sexual desire to a lack of sexual desire for the current partner. The condition may start after a period of normal sexual functioning, or the person may always have had an absence or a lesser intensity of sexual desire.


The causes vary considerably but include a decrease in the production of normal  estrogen  in women, or  testosterone  in both men and women. Other causes may be aging, fatigue, pregnancy, medications (such as  SSRIs ), or psychiatric conditions, such as  depression  and  anxiety . While many causes of low sexual desire are cited, only a few of these have ever been the object of empirical research. [ 7 ]


Sexual arousal disorders were previously known as  frigidity  in women and  impotence  in men, though these have now been replaced with less judgmental terms. Impotence is now known as  erectile dysfunction , and frigidity has been replaced with a number of terms describing specific problems that can be broken down into four categories as described by the  American Psychiatric Association's   Diagnostic and Statistical Manual of Mental Disorders : lack of desire, lack of arousal, pain during intercourse, and lack of orgasm. [ 8 ]


For both men and women, these conditions can manifest themselves as an aversion to and avoidance of sexual contact with a partner. In men, there may be partial or complete failure to attain or maintain an erection, or a lack of sexual excitement and pleasure in sexual activity.


There may be physiological origins to these disorders, such as decreased blood flow or lack of vaginal lubrication. Chronic disease and the partners' relationship can also contribute to dysfunction.


Additionally,  postorgasmic illness syndrome  (POIS) may cause symptoms when aroused, including adrenergic-type presentation: rapid breathing,  paresthesia , palpitations, headaches,  aphasia , nausea, itchy eyes, fever, muscle pain and weakness, and fatigue.


From the onset of arousal, symptoms can persist for up to a week in patients.


The cause of this condition is unknown; however, it is believed to be a pathology of either the immune system or autonomic nervous systems. It is defined as a rare disease by the  National Institute of Health , but the prevalence is unknown. It is not thought to be psychiatric in nature, but it may present as anxiety relating to coital activities and may be incorrectly diagnosed as such. There is no known cure or treatment. [ 9 ]


Erectile dysfunction (ED), or impotence, is a sexual dysfunction characterized by the inability to develop or maintain an erection of the  penis . There are various underlying causes of ED, including damage to anatomical structures, psychological causes, medical disease, and drug use. Many of these causes are medically treatable.


Psychological ED can often be treated by almost anything that the patient believes in; there is a very strong  placebo  effect. Physical damage can be more difficult to treat. One leading physical cause of ED is continual or severe damage taken to the  nervi erigentes , which can prevent or delay erection. These nerves course beside the prostate arising from the  sacral plexus  and can be damaged in prostatic and  colorectal surgeries .


Diseases are also common causes of erectile dysfunction. Diseases such as  cardiovascular disease ,  multiple sclerosis ,  kidney failure ,  vascular disease , and  spinal cord  injury can cause erectile dysfunction. [ 10 ]  Cardiovascular disease can decrease blood flow to penile tissues, making it difficult to develop or maintain an erection.


Due to the shame and embarrassment felt by some with erectile dysfunction, the subject was  taboo  for a long time and is the focus of many urban legends.  Folk remedies  have long been advocated, with some being advertised widely since the 1930s. The introduction of perhaps the first pharmacologically effective remedy for impotence,  sildenafil  (trade name Viagra), in the 1990s caused a wave of public attention, propelled in part by the newsworthiness of stories about it and heavy  advertising .


It is estimated that around 30 million men in the United States and 152 million men worldwide have erectile dysfunction. [ 11 ] [ 12 ]  However,  social stigma ,  low health literacy , and social  taboos  lead to under reporting which makes an accurate prevalence rate hard to determine.


The Latin term  impotentia coeundi  describes the inability to insert the penis into the  vagina , and has been mostly replaced by more precise terms.


ED from  vascular disease  is seen mainly amongst older individuals who have  atherosclerosis . Vascular disease is common in individuals who smoke or have  diabetes ,  peripheral vascular disease , or  hypertension . Any time  blood flow  to the penis is impaired, ED can occur.


Drugs are also a cause of erectile dysfunction. Individuals who take drugs that lower  blood pressure ,  antipsychotics ,  antidepressants , sedatives, narcotics, antacids, or alcohol can have problems with  sexual function  and loss of libido. [ 13 ]


Hormone  deficiency is a relatively rare cause of erectile dysfunction. In individuals with testicular failure, as in  Klinefelter syndrome , or those who have had  radiation therapy ,  chemotherapy , or childhood exposure to the  mumps virus , the testes may fail to produce testosterone. Other hormonal causes of erectile failure include brain tumors,  hyperthyroidism ,  hypothyroidism , or  adrenal gland  disorders. [ 14 ]


Anorgasmia  is classified as persistent delays or absence of orgasm following a normal sexual excitement phase in at least 75% of sexual encounters. [ 15 ] : 368   The disorder can have physical, psychological, or pharmacological origins.  SSRI  antidepressants are a common pharmaceutical culprit, as they can delay orgasm or eliminate it entirely. A common physiological cause of anorgasmia is  menopause ; one in three women report problems obtaining an orgasm during sexual stimulation following menopause. [ 16 ]


Premature ejaculation is when ejaculation occurs before the partner achieves orgasm, or a mutually satisfactory length of time has passed during intercourse. There is no correct length of time for intercourse to last, but generally, premature ejaculation is thought to occur when ejaculation occurs in under two minutes from the time of the insertion of the penis. [ 17 ]  For a diagnosis, the patient must have a chronic history of premature ejaculation, poor ejaculatory control, and the problem must cause feelings of dissatisfaction as well as distress for the patient, the partner, or both. [ 18 ]


Premature ejaculation has historically been attributed to psychological causes, but newer theories suggest that premature ejaculation may have an underlying neurobiological cause that may lead to rapid ejaculation. [ 19 ]


Post-orgasmic disorders cause symptoms shortly after  orgasm  or  ejaculation .  Post-coital tristesse  (PCT) is a feeling of  melancholy  and  anxiety  after sexual intercourse that lasts for up to two hours.  Sexual headaches  occur in the skull and neck during sexual activity, including  masturbation , arousal or orgasm.


In men,  post orgasmic illness syndrome (POIS)  causes severe  muscle pain  throughout the body and other symptoms immediately following  ejaculation . These symptoms last for up to a week. [ 20 ] [ 21 ] [ 22 ]  Some doctors speculate that the frequency of POIS "in the population may be greater than has been reported in the academic literature", [ 23 ]  and that many with POIS are undiagnosed. [ 24 ]


POIS may involve adrenergic symptoms: rapid breathing,  paresthesia ,  palpitations ,  headaches ,  aphasia ,  nausea , itchy eyes,  fever ,  muscle pain  and  weakness , and  fatigue .


The etiology of this condition is unknown; however, it is believed to be a pathology of either the immune system or autonomic nervous systems. It is defined as a rare disease by the NIH, but the prevalence is unknown. It is not thought to be psychiatric in nature, but it may present as anxiety relating to coital activities and thus may be incorrectly diagnosed as such. There is no known cure or treatment. [ 9 ]


Dhat syndrome  is another condition which occurs in men: it is a  culture-bound syndrome  which causes anxious and  dysphoric  mood after sex. It is distinct from the low-mood and concentration problems (acute aphasia) seen in POIS.


Sexual pain disorders in women include  dyspareunia  (painful intercourse) and  vaginismus  (an involuntary spasm of the muscles of the vaginal wall that interferes with intercourse).


Dyspareunia may be caused by  vaginal dryness . Poor lubrication may result from insufficient excitement and stimulation, or from hormonal changes caused by  menopause ,  pregnancy , or breastfeeding. Irritation from contraceptive creams and foams can also cause dryness, as can fear and anxiety about sex.


It is unclear exactly what causes vaginismus, but it is thought that past sexual trauma (such as  rape  or  abuse ) may play a role. Another female sexual pain disorder is  vulvodynia , or  vulvar vestibulitis  when localized to the  vulval vestibule . In this condition, women experience burning pain during sex, which seems to be related to problems with the skin in the vulvar and vaginal areas. Its cause is unknown.


In men, structural abnormalities of the penis like  Peyronie's disease  can make sexual intercourse difficult and/or painful. The disease is characterized by thick fibrous bands in the penis that lead to excessive curvature during erection. [ 25 ] [ unreliable medical source? ]  It has an incidence estimated at 0.4–3% or more, [ 26 ]  is most common in men 40–70, [ 26 ]  and has no certain cause. Risk factors include genetics, minor trauma (potentially during  cystoscopy  or  transurethral resection of the prostate ), chronic systemic vascular diseases, smoking, and alcohol consumption. [ 27 ]


Priapism  is a painful erection that occurs for several hours and occurs in the absence of  sexual stimulation . This condition develops when blood is trapped in the penis and is unable to drain. If the condition is not promptly treated, it can lead to severe scarring and permanent loss of erectile function. The disorder is most common in young men and children. Individuals with  sickle-cell disease  and those who use certain medications can often develop this disorder. [ 28 ]


There are many factors which may result in a person experiencing a sexual dysfunction. These may result from emotional or physical causes. Emotional factors include interpersonal or psychological problems, which include  depression , sexual fears or guilt, past sexual trauma, and sexual disorders. [ 29 ]


Sexual dysfunction is especially common among people who have  anxiety disorders . [ 2 ] [ 30 ] [ 31 ] [ 5 ]  Ordinary anxiety can cause erectile dysfunction in men without psychiatric problems, but clinically diagnosable disorders such as  panic disorder  commonly cause avoidance of intercourse and premature ejaculation. [ 32 ]  Pain during intercourse is often a comorbidity of anxiety disorders among women. [ 33 ]


Physical factors that can lead to sexual dysfunctions include the use of drugs, such as alcohol,  nicotine ,  narcotics , stimulants,  antihypertensives ,  antihistamines , and some psychotherapeutic drugs. [ 34 ]  For women, almost any physiological change that affects the reproductive system— premenstrual syndrome , pregnancy and the postpartum period, and menopause—can have an adverse effect on libido. [ 34 ]  Back injuries may also impact sexual activity, as can problems with an enlarged prostate gland, problems with blood supply, or nerve damage (as in  sexual dysfunction after spinal cord injuries ). Diseases such as  diabetic neuropathy ,  multiple sclerosis ,  tumors , and, rarely, tertiary  syphilis  may also impact activity, as can the failure of various organ systems (such as the heart and lungs),  endocrine  disorders ( thyroid ,  pituitary , or  adrenal gland  problems), hormonal deficiencies (low  testosterone , other  androgens , or  estrogen ), and some  birth defects .


In the context of heterosexual relationships, one of the main reasons for the decline in sexual activity among these couples is the male partner experiencing erectile dysfunction. This can be very distressing for the male partner, causing poor body image, and it can also be a major source of low desire for these men. [ 35 ]  In aging women, it is natural for the vagina to  narrow and atrophy . If a woman does not participate in sexual activity regularly (in particular, activities involving vaginal penetration), she will not be able to immediately accommodate a penis without risking pain or injury if she decides to engage in penetrative intercourse. [ 35 ]  This can turn into a vicious cycle that often leads to female sexual dysfunction. [ 35 ]


According to Emily Wentzell, American culture has anti-aging sentiments that have caused sexual dysfunction to become "an illness that needs treatment" instead of viewing it as a natural part of the aging process. Not all cultures seek treatment; for example, a population of men living in Mexico often accept ED as a normal part of their maturing sexuality. [ 36 ]


Sexual problems are common with SSRIs, [ 37 ]  which can cause  anorgasmia ,  erectile dysfunction , diminished  libido , genital numbness, and  sexual anhedonia  (pleasureless orgasm). [ 38 ]   Poor sexual function is also one of the most common reasons people stop the medication. [ 39 ]  In some cases, symptoms of sexual dysfunction may persist after discontinuation of SSRIs. [ 38 ] [ 40 ] [ 41 ] : 14  [ 42 ] [ 43 ]  This combination of symptoms is sometimes referred to as  post-SSRI sexual dysfunction . [ 44 ] [ 45 ]


Pelvic floor dysfunction can be an underlying cause of sexual dysfunction in both women and men, and is treatable by  pelvic floor physical therapy , a type of physical therapy designed to restore the health and function of the pelvic floor and surrounding areas. [ 46 ] [ 47 ] [ 48 ] [ 49 ] [ 50 ]


Several theories have looked at female sexual dysfunction, from medical to psychological perspectives. Three social psychological theories include: the self-perception theory, the overjustification hypothesis, and the insufficient justification hypothesis:


The prevalence of sexual dysfunction in women is not well known due to a paucity of epidemiological studies, inconsistent criteria for sexual dysfunction across different studies and incomplete recruitment, with studies often excluding women who were without a partner or who were sexually inactive. However, based on incomplete population based studies from the United States, Europe and Australia, unspecified arousal dysfunction (in which a woman is unable to achieve desirable genital or non-genital sexual arousal despite adequate stimulation and desire) was present in 3-9% of women aged 18–44, 5-7.5% aged 45–64 and 3-6% in women older than 65. [ 51 ]  Anorgasmia with distress (in which women were unable to achieve an orgasm) was present in 7-8% of women younger than 40, 5-7% aged 40–64 and 3-6% of those older than 65. [ 51 ]  Poor sexual self image leading to distress was seen in 13.4% of women younger than 40 in an Australian population based study. [ 51 ]


The importance of how a woman perceives her behavior should not be underestimated. Many women perceive sex as a chore as opposed to a pleasurable experience, and they tend to consider themselves sexually inadequate, which in turn does not motivate them to engage in sexual activity. [ 35 ]  Several factors influence a women's perception of her sexual life. These can include race, gender, ethnicity, educational background, socioeconomic status, sexual orientation, financial resources, culture, and religion. [ 35 ]  Cultural differences are also present in how women view menopause and its impact on health, self-image, and sexuality. A study found that African American women are the most optimistic about menopausal life; Caucasian women are the most anxious, Asian women are the most inhibited about their symptoms, and Hispanic women are the most stoic. [ 35 ]


Since these women have sexual problems, their sexual lives with their partners can become a burden without pleasure, and may eventually lose complete interest in sexual activity. Some of the women found it hard to be aroused mentally, while others had physical problems. Several factors can affect female dysfunction, such as situations in which women do not trust their sex partners, the environment where sex occurs being uncomfortable, or an inability to concentrate on the sexual activity due to a bad mood or burdens from work. Other factors include physical discomfort or difficulty in achieving arousal, which could be caused by aging or changes in the body's condition. [ 52 ]


Sexual assault  has been associated with excessive menstrual bleeding, genital burning, and painful intercourse (attributable to disease, injury, or otherwise), medically unexplained dysmenorrhea, menstrual irregularity, and lack of sexual pleasure. [ citation needed ]  Physically violent assaults and those committed by strangers were most strongly related to reproductive symptoms. Multiple assaults, assaults accomplished by persuasion, spousal assault, and completed intercourse were most strongly related to sexual symptoms. [ citation needed ]  Assault was occasionally associated more strongly with reproductive symptoms among women with lower income or less education, possibly because of economic stress or differences in assault circumstances. Associations with unexplained menstrual irregularity were strongest among African American women; ethnic differences in reported circumstances of assault appeared to account for these differences. Assault was associated with sexual indifference only among Latinas. [ 53 ]


The most prevalent of female sexual dysfunctions that have been linked to menopause include lack of desire and libido; these are predominantly associated with hormonal physiology. Specifically, the decline in serum estrogens causes these changes in sexual functioning. Androgen depletion may also play a role, but current knowledge about this is less clear. The hormonal changes that take place during the menopausal transition have been suggested to affect women's sexual response through several mechanisms, some more conclusive than others.


Whether or not aging directly affects women's sexual functioning during menopause is controversial. However, many studies have demonstrated that aging has a powerful impact on sexual function and dysfunction in women, specifically in the areas of desire, sexual interest, and frequency of orgasm. [ 3 ] [ 35 ] [ 54 ]  The primary predictor of sexual response throughout menopause is prior sexual functioning, [ 3 ]  which means that it is important to understand how the physiological changes in men and women can affect sexual desire. [ 35 ]  Despite the apparent negative impact that menopause can have on sexuality and sexual functioning, sexual confidence and well-being can improve with age and menopausal status. [ 3 ]


Testosterone, along with its metabolite  dihydrotestosterone , is important to normal sexual function in men and women. Dihydrotestosterone is the most prevalent androgen in both men and women. [ 35 ]  Testosterone levels in women at age 60 are on average about half of what they were before the women were 40. Although this decline is gradual for most women, those who have undergone  bilateral oophorectomy  experience a sudden drop in testosterone levels, as the ovaries produce 40% of the body's circulating testosterone. [ 35 ]


Sexual desire has been related to three separate components: drive, beliefs and values, and motivation. [ 35 ]  Particularly in postmenopausal women, drive fades and is no longer the initial step in a woman's sexual response. [ 35 ]


The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders lists the following sexual dysfunctions:


Additional DSM sexual disorders that are not sexual dysfunctions include:


Several decades ago, the medical community believed most sexual dysfunction cases were related to psychological issues.  Although this may be true for a portion of men, the vast majority of cases have now been identified to have a physical cause or correlation. [ 61 ]  If the sexual dysfunction is deemed to have a psychological component or cause,  psychotherapy  can help. Situational anxiety arises from an earlier bad incident or lack of experience, and often leads to development of fear towards sexual activity and avoidance which enters a cycle of increased anxiety and  desensitization  of the penis. In some cases, erectile dysfunction may be due to marital disharmony. Marriage  counseling  sessions are recommended in this situation.


Lifestyle changes such as discontinuing  tobacco smoking  or substance use can also treat some types of ED. [ 62 ]  Several oral medications like  Viagra ,  Cialis , and  Levitra  have become available to alleviate ED and have become first line therapy. These medications provide an easy, safe, and effective treatment solution for approximately 60% of men. In the rest, the medications may not work because of wrong diagnosis or  chronic  history. [ citation needed ]


Another type of medication that is effective in roughly 85% of men is called intracavernous pharmacotherapy, which involves injecting a vasodilator drug directly into the penis to stimulate an erection. [ 63 ]  This method has an increased risk of priapism if used in conjunction with other treatments, and localized pain. [ 18 ]


Premature ejaculations  are treated by behavioural techniques Squeeze technique and Stop Start Technique. In Squeeze technique the area between head and shaft of penis is pressed using index finger and thumb just before ejaculation. In Stop Start Technique the male partner stops having sexual intercourse just before ejaculation and waits for the sense of ejaculation to pass away. Both Techniques are repeated many times. [ 64 ]


When conservative therapies fail, are an unsatisfactory treatment option, or are contraindicated for use, the insertion of a  penile implant  may be selected by the patient. Technological advances have made the insertion of a penile implant a safe option for the treatment of ED, which provides the highest patient and partner satisfaction rates of all available ED treatment options. [ 65 ]


Pelvic floor physical therapy has been shown to be a valid treatment for men with sexual problems and pelvic pain. [ 66 ]


The 2020 guidelines from the  American College of Physicians  support the discussion of  testosterone  treatment in adult men with age-related  low levels of testosterone  who have sexual dysfunction. They recommend yearly evaluation regarding possible improvement and, if none, to discontinue testosterone; intramuscular treatments should be considered rather than transdermal treatments due to costs and since the effectiveness and harm of either method is similar. Testosterone treatment for reasons other than possible improvement of sexual dysfunction may not be recommended. [ 67 ] [ 68 ]


In 2015,  flibanserin  was approved in the US to treat decreased sexual desire in women. While it is effective for some women, it has been criticized for its limited efficacy, and has many warnings and contraindications that limit its use. [ 69 ]  Flibanserin was found to increase pleasurable sexual experiences by 0.5 events per month in trials. Possible side effects include dizziness, drowsiness, nausea and fatigue. [ 51 ]  Flibanserin should not be taken with alcohol. [ 51 ]   Bremelanotide  has been shown to modestly increase sexual desire in women, but it has not shown evidence of increasing the number of satisfactory sexual experiences per month. Possible side effects include nausea, flushing and headaches. [ 51 ]  Women experiencing pain with intercourse are often prescribed pain relievers or desensitizing agents; others are prescribed  vaginal lubricants . Many women with sexual dysfunction are also referred to a  counselor  or  sex therapist . [ 70 ]  Counselling for female sexual dysfunction, including  sexual counselling ,  cognitive behavioral therapy , body awareness counselling, and  couples counselling  have been found to be helpful. [ 51 ]


Estrogen replacement therapy, outside of the indicated use for menopausal symptoms, is not recommended for the treatment of sexual dysfunction in women. [ 51 ]


Estrogens are responsible for the maintenance of collagen, elastic fibers, and vasculature of the urogenital tract, all of which are important in maintaining vaginal structure and functional integrity; they are also important for maintaining vaginal pH and moisture levels, both of which help to keep the tissues lubricated and protected. [ 3 ]  Prolonged estrogen deficiency leads to atrophy, fibrosis, and reduced blood flow to the urogenital tract, which cause menopausal symptoms such as vaginal dryness and pain related to sexual activity and/or intercourse. [ 3 ]  Women experiencing vaginal dryness who cannot use commercial lubricants may be able to use coconut oil as an alternative. [ 71 ]


Androgen therapy for hypoactive sexual desire disorder has a small benefit but its safety is not known. [ 72 ]  It is not approved as a treatment in the United States. [ 72 ]  It is more commonly used among women who have had an oophorectomy or are in a postmenopausal state. However, like most treatments, this is also controversial. One study found that after a 24-week trial, women taking androgens had higher scores of sexual desire compared to a placebo group. [ 3 ]  As with all pharmacological drugs, there are side effects in using androgens, which include  hirsutism , acne,  polycythaemia , increased high-density lipoproteins, cardiovascular risks, and  endometrial hyperplasia . [ 3 ]  Alternative treatments include topical estrogen creams and gels that can be applied to the vulva or vagina area to treat vaginal dryness and atrophy. [ 3 ]


In modern times, clinical study of sexual problems is usually dated back no earlier than 1970 when  Masters and Johnson's   Human Sexual Inadequacy  was published. It was the result of over a decade of work at the Reproductive Biology Research Foundation in St. Louis, involving 790 cases. The work grew from Masters and Johnson's earlier  Human Sexual Response  (1966).


Prior to Masters and Johnson, the clinical approach to sexual problems was largely derived from  Sigmund Freud . It was held to be  psychopathology  and approached with a certain pessimism regarding the chance of help or improvement. Sexual problems were merely symptoms of a deeper malaise, and the diagnostic approach was from the psychopathological viewpoint. There was little distinction between difficulties in function and variations nor between perversion and problems. Despite work by psychotherapists such as Balint sexual difficulties were crudely split into frigidity or impotence, terms which acquired negative connotations in popular culture.


Human Sexual Inadequacy  moved thinking from psychopathology to learning; psychopathological problems would only be considered if a problem did not respond to educative treatment. Treatment was directed at couples, whereas before partners would be seen individually. Masters and Johnson believed that sex was a joint act, and that sexual communication was the key issue to sexual problems, not the specifics of an individual problem. They also proposed  co-therapy , with a pair of therapists to match the clients, arguing that a lone male therapist could not fully comprehend female difficulties.


The basic Masters and Johnson treatment program was an intensive two-week program to develop efficient sexual communication. The program is couple-based and therapist-led, and began with discussion and sensate focus between the couple to develop shared experiences. From the experiences, specific difficulties could be determined and approached with a specific therapy. In a limited number of male-only cases (41) Masters and Johnson developed the use of a female surrogate, which was abandoned over the ethical, legal, and other problems it raised.


In defining the range of sexual problems, Masters and Johnson defined a boundary between dysfunction and deviations. Dysfunctions were transitory and experienced by most people, and included male primary or secondary impotence, premature ejaculation, and  ejaculatory incompetence ; female primary  orgasmic dysfunction  and situational orgasmic dysfunction; pain during intercourse (dyspareunia) and vaginismus. According to Masters and Johnson,  sexual arousal  and  climax  are a normal physiological process of every functionally intact adult, but they can be inhibited despite being autonomic responses. Masters and Johnson's treatment program for dysfunction was 81.1% successful.


Despite Masters and Johnson's work, sexual therapy in the US was overrun by enthusiastic rather than systematic approaches, blurring the space between "enrichment" and therapy.


Vasocongestion ,  vascular congestion  or  vascular engorgement  is the swelling of bodily tissues caused by increased  vascular   blood  flow and a localized increase in  blood pressure . Typical causes of vasocongestion in humans includes  menstruation ,  sexual arousal ,  REM sleep , strong  emotions ,  illnesses ,  deep venous thrombosis  (DVT) and  allergic reactions .


Menstrual cramps  are one of the most common side effects of vasocongestion in adult females. Although pain and discomfort varies among individuals, vasocongestion is an essential part of the shedding of the lining of the  uterus . Abnormal vasocongestion during the menstrual cycle can lead to irregular bleeding, severe and debilitating cramps and  anemia  caused by increased menstrual flow.


The temporary vasocongestion of the  cheeks  of the  face  is called  blushing . It may be caused by the emotions of  anger  or  embarrassment . The illness of  rosacea  is a chronic vasocongestion condition of the face that primarily affects the cheeks and nose, but may include other areas such as the eyes and chin.


Vasocongestion of the area around the  human anus  can lead to the formation of  hemorrhoids . [ medical citation needed ]


Vasocongestion is essential for  sexual procreation in mammals  since this is the force that causes the hardening of a  penis  during an  erection . The same force leads to the  hardening of the clitoris  and  vaginal lubrication  during sexual arousal. [ 1 ]  The decrease in vasocongestion in post- menopausal  women may require some women to use artificial  sexual lubricant  to avoid pain during  sexual intercourse . If there is pain however, sexual drive is typically diminished or absent.


Other forms of vasocongestion during human sexual activity include  sex flush  and the swelling of  nipples  in both men and women. [ 2 ]


Unpleasant side effects of sex-related vasocongestion accompanied by sexual inactivity may lead to the  cramp -like pain of " blue balls " [ 3 ]  in males and an unpleasant  pelvic  "heaviness" in women, [ 4 ]  similar to the start of the menstruation cycle.


Human  sexual reproduction , to produce  offspring , begins with  fertilization . Successful reproduction typically involves  sexual intercourse  between a healthy,  sexually mature  and  fertile   male  and  female . [ 1 ]  During sexual intercourse, sperm cells are  ejaculated  into the  vagina  through the  penis , resulting in fertilization of an  ovum  to form a  zygote . [ 1 ]


While normal cells contain 46  chromosomes  (23 pairs),  gamete  cells contain only half that number, and it is when these two cells merge into one combined zygote cell that  genetic recombination  occurs. [ 2 ]  The zygote then undergoes a defined development process that is known as human  embryogenesis , and this starts the typical 38-week  gestation period [ a ]  for the  embryo  (and eventually  foetus ) that is followed by  childbirth .


Assisted reproductive technology  also exists, like  IVF , some of which involve alternative methods of fertilization, which do not involve sexual intercourse; the fertilization of the ovum may be achieved by  artificial insemination  methods. [ 3 ]


In order for human reproduction to be achieved, an individual must have undergone  puberty  first, requiring  ovulation  in females and the  spermarche  in males to have occurred prior to engaging in  sexual intercourse  or achieving  pregnancy  through non-penetrative means. Before puberty, humans are  infertile , as their genitals lack reproductive function (only being able to discharge  urine ).


Legal factors also play a vital role in the achievement of human reproduction: a  minor  under the  age of consent  cannot give legal consent to sexual intercourse or artificial alternatives to reproduction, the former case of which is liable to have the older party charged with  statutory rape , depending on jurisdictions. [ 4 ] [ 5 ]  Even for minors above the age of consent,  comprehensive sex education  advises both consenting parties to use  contraception  to avoid both  sexually transmitted infections  and  early, unplanned/unwanted pregnancies . Pregnancy in girls under the age of 15 is especially discouraged due to their reproductive systems having yet to reach full maturity. [ 6 ]


The male reproductive system contains two main divisions: the  testicles  where  sperm  are produced, and the  penis  where  semen  is  ejaculated  through the  urethra . In humans, both of these organs are outside the  abdominal cavity . Having the testicles outside the abdomen facilitates temperature regulation of the sperm, which require specific temperatures to survive about 2-3 °C less than the normal body temperature i.e. 37 °C. In particular, the extraperitoneal location of the testicles may result in a 2-fold reduction in the heat-induced contribution to the spontaneous mutation rate in male germinal tissues compared to tissues at 37 °C. [ 7 ]  If the testicles remain too close to the body, it is likely that the increase in temperature will harm the spermatozoa formation, making conception more difficult. This is why the testes are carried in an external  scrotum  rather than within the abdomen; they normally remain slightly cooler than body temperature, facilitating sperm production.


Male  germ cells  produced in the testes are able to perform special  DNA repair  processes during meiosis that act to repair DNA damages and to maintain the integrity of the  genomes  that are to be passed on to progeny. [ 8 ]   Two of these DNA repair processes are  homologous recombinational  repair and  non-homologous end joining . [ 8 ]


The female reproductive system likewise contains two main divisions: the external genitalia (the  vulva ) and the internal genitalia.


The  ovum  meets with the  sperm cell : a sperm may penetrate and merge with the egg, fertilizing it with the help of certain hydrolytic enzymes present in the acrosome. The fertilization usually occurs in the  fallopian tubes , but can happen in the uterus itself. The  zygote  then becomes  implanted  in the lining of the uterus, where it begins the processes of  embryogenesis  and  morphogenesis . When the  fetus  is developed enough to survive outside of the  uterus , the cervix dilates and contractions of the uterus propel it through the birth canal, which is the  vagina , and thereby gives external life to the newborn  infant . This process is called  childbirth .


The ova, which are the female sex cells, are much larger than the spermatozoon and are normally formed within the  ovaries  of the female fetus before birth. They are mostly fixed in location within the ovary until their transit to the uterus, and contain nutrients for the later  zygote  and  embryo . Over a regular interval known as the  menstrual cycle , in response to hormonal signals, a process of  oogenesis  matures one ovum which is released and sent down the fallopian tube. If not fertilized, this egg is flushed out of the system through  menstruation .


Oocytes  (female germ cells) located in the  primordial follicle  of the ovary are in a non-growing  prophase  arrested state, but are able to undergo highly efficient  homologous recombinational  repair of  DNA damages  including double-strand breaks. [ 9 ]   This capability allows the maintenance of  genome  integrity and protection of the health of offspring. [ 9 ]


Human reproduction normally begins with copulation, though it may be achieved through  artificial insemination , and is followed by nine months of pregnancy before childbirth. Pregnancy can be avoided with the use of contraceptives such as  condoms  and  intrauterine devices . [ 10 ]


Human reproduction naturally takes place as  internal fertilization  by sexual intercourse. During this process, the man inserts his erect  penis  into the woman's  vagina  and then either partner initiates rhythmic  pelvic thrusts  until the man achieves  orgasm , which leads to  ejaculation  of  semen  containing sperm into the vaginal canal. The sperm and the ovum are known as the  gametes  (each containing half the genetic information of the parent, created through  meiosis ). [ 2 ]  The sperm (being one of approximately 250 million sperm in a typical ejaculation) travels through the vagina and cervix into the uterus or fallopian tubes. Only 1 in 14 million of the ejaculated sperm will reach the fallopian tube. The egg simultaneously moves through the fallopian tube away from the ovary. One of the sperm encounters, penetrates and fertilizes the ovum, creating a  zygote . Upon  fertilization  and  implantation , gestation of the fetus then occurs within the uterus. [ 11 ] [ 12 ] [ 13 ] [ 14 ]


Pregnancy rates for sexual intercourse  are highest during the  menstrual cycle  time from some 5 days before until 1 to 2 days after ovulation. [ 16 ]  For optimal pregnancy chance, there are recommendations of sexual intercourse every 1 or 2 days, [ 17 ]  or every 2 or 3 days. [ 18 ]  Studies have shown no significant difference between different  sex positions  and pregnancy rate, as long as it results in  ejaculation  into the vagina. [ 19 ]


As an alternative to natural sexual intercourse, there exists  artificial insemination , where sperm is introduced into the female reproductive system without the insertion of the penis. [ 3 ]  There are also many methods of  assisted reproductive technology , such as  in vitro fertilization , where one or more  egg cells  are retrieved from a woman's ovaries and co-incubated with sperm outside the body. The resulting embryo can then be reinserted into the womb of the woman. [ citation needed ]


Pregnancy is the period of time during which the fetus develops, dividing via  mitosis  inside the uterus. During this time, the fetus receives all of its  nutrition  and oxygenated blood from the mother, filtered through the  placenta , which is attached to the fetus'  abdomen  via an  umbilical cord . This drain of  nutrients  can be quite taxing on the mother, who is required to ingest slightly higher levels of  calories . In addition, certain  vitamins  and other nutrients are required in greater quantities than normal, often creating abnormal eating habits. Gestation period is about 266 days in humans. While in the uterus, the baby first endures a very brief zygote stage, then the embryonic stage, which is marked by the development of major organs and lasts for approximately eight weeks, then the fetal stage, which revolves around the development of bone cells while the fetus continues to grow in size. [ 20 ]  It is estimated that about 3-5% of couples are infertile and the fecunditity of couples is around 30% for each menstrual cycle. [ 21 ]


Labor is separated into 4 stages. The first stage involves latent phase and active phase separated by the dilation of the cervix for 6 to 10 cm. The second stage is the pushing stage. The third stage involves the delivery of the placenta. And the last stage is the contraction of the uterus. [ 22 ]  Once the fetus is sufficiently developed, chemical signals begin the process of birth, which begins with the fetus being pushed out of the birthing canal. The newborn, which is called an  infant  in humans, should typically begin  respiration  on its own shortly after birth. Not long after, the placenta eventually falls off on its own. The person assisting the birth may also sever the umbilical cord.


While most ancient human societies believed that  sexual intercourse  was necessary for reproduction, the reasons some sex did not result in children, and the mechanism by which mating produced children were not understood. The theory of  preformationism  was popular in  Ancient Greece  and  Christendom  for centuries. Because they are too small to see with the naked eye, it was only after his invention of the microscope that  Antonie van Leeuwenhoek  discovered  spermatozoa  in 1677.  Mitosis  and  meiosis  were not discovered until the late 1800s.


Altrui - The Human Egg Cell Explained


Assisted reproductive technology  ( ART ) includes medical procedures used primarily to address  infertility . This subject involves procedures such as  in vitro fertilization  (IVF),  intracytoplasmic sperm injection  (ICSI),  cryopreservation  of gametes or embryos, and/or the use of  fertility medication . When used to address infertility, ART may also be referred to as  fertility treatment.  ART mainly belongs to the field of  reproductive endocrinology and infertility . Some forms of ART may be used with regard to fertile couples for genetic purpose (see  preimplantation genetic diagnosis ). ART may also be used in  surrogacy  arrangements, although not all surrogacy arrangements involve ART.
The existence of sterility will not always require ART to be the first option to consider, as there are occasions when its cause is a mild disorder that can be solved with more conventional treatments or with behaviors based on promoting health and reproductive habits.


With ART, the process of  sexual intercourse  is bypassed and fertilization of the  oocytes  occurs in the laboratory environment (i.e.,  in vitro fertilization ). [ citation needed ]


In the US, the  Centers for Disease Control and Prevention  (CDC) defines ART to include "all fertility treatments in which both eggs and sperm are handled. In general, ART procedures involve surgically removing eggs from a woman's ovaries, combining them with sperm in the laboratory, and returning them to the woman's body or donating them to another woman." According to CDC, "they do not include treatments in which only sperm are handled (i.e., intrauterine—or artificial—insemination) or procedures in which a woman takes medicine only to stimulate egg production without the intention of having eggs retrieved." [ 1 ]


In Europe, ART also excludes artificial insemination and includes only procedures where oocytes are handled. [ 2 ] [ 3 ]


The  World Health Organization  (WHO), also defines ART this way. [ 4 ]


Ovulation induction  is usually used in the sense of stimulation of the development of  ovarian follicles [ 5 ] [ 6 ] [ 7 ]  by  fertility medication  to reverse  anovulation  or  oligoovulation . These medications are given by injection for 8 to 14 days. A health care provider closely monitors the development of the eggs using transvaginal ultrasound and blood tests to assess follicle growth and estrogen production by the ovaries. When follicles have reached an adequate size and the eggs are mature enough, an injection of the hormone hCG initiates the ovulation process. Egg retrieval should occur 36 hours before ovulation.


In vitro fertilization  is the technique of letting  fertilization  of the male and female  gametes  (sperm and egg) occur outside the female body.


Techniques usually used in in vitro fertilization include:


Less commonly used techniques in in vitro fertilization are:


A  pre-implantation genetic diagnosis  procedure may be conducted on  embryos  prior to  implantation  (as a form of  embryo profiling ), and sometimes even of  oocytes  prior to  fertilization . PGD is considered in a similar fashion to  prenatal diagnosis . PGD is an adjunct to ART procedures, and requires in vitro fertilization to obtain  oocytes  or  embryos  for evaluation. Embryos are generally obtained through blastomere or blastocyst biopsy. The latter technique has proved to be less deleterious for the embryo, therefore it is advisable to perform the biopsy around day 5 or 6 of development. [ 9 ]   Sex selection  is the attempt to control the sex of offspring to achieve a desired sex in case of X chromosome linked diseases. It can be accomplished in several ways, both pre- and post-implantation of an embryo, as well as at birth. Pre-implantation techniques include PGD, but also  sperm sorting . [ citation needed ]


Other assisted reproduction techniques include:


The majority of IVF-conceived infants do not have  birth defects . [ 13 ]
However, some studies have suggested that assisted reproductive technology is associated with an increased risk of birth defects. [ 14 ] [ 15 ]
Artificial reproductive technology is becoming more available. Early studies suggest that there could be an increased risk for medical complications with both the mother and baby. Some of these include low birth weight, placental insufficiency, chromosomal disorders, preterm deliveries, gestational diabetes, and  pre-eclampsia  (Aiken and Brockelsby). [ 16 ]


In the largest U.S. study, which used data from a statewide registry of birth defects, [ 17 ]
6.2% of IVF-conceived children had major defects, as compared with 4.4% of naturally conceived children matched for  maternal age  and other factors ( odds ratio , 1.3; 95%  confidence interval , 1.00 to 1.67). [ 13 ]  ART carries with it a risk for  heterotopic pregnancy  (simultaneous intrauterine and extrauterine pregnancy). [ 18 ]
The main risks are:


Sperm donation  is an exception, with a birth defect rate of almost a fifth compared to the general population. It may be explained by that sperm banks accept only people with high sperm count.


Germ cells  of the mouse normally have a frequency of spontaneous point  mutations  that is 5 to 10-fold lower than that in  somatic cells  from the same individual. [ 22 ]   This low frequency in the  germline  leads to  embryos  that have a low frequency of point mutations in the next generation.  No significant differences were observed in the frequency or spectrum of mutations between naturally conceived fetuses and assisted-conception fetuses. [ 22 ]   This suggests that with respect to the maintenance of genetic integrity assisted conception is safe. [ 22 ]


Current data indicate little or no increased risk for  postpartum depression  among women who use ART. [ 23 ]


Study results indicate that ART can affect both women and men's sexual health negatively. [ 24 ]


Usage of assisted reproductive technology including  ovarian stimulation  and  in vitro fertilization  have been associated with an increased overall risk of  childhood cancer  in the offspring, which may be caused by the same original disease or condition that caused the infertility or subfertility in the mother or father. [ 25 ]


That said, In a landmark paper by Jacques Balayla et al. it was determined that infants born after ART have similar neurodevelopment than infants born after natural conception. [ 26 ]


ART may also pose risks to the mother. A large US database study compared pregnancy outcomes among 106,000 assisted conception pregnancies with 34 million natural conception pregnancies. It found that assisted conception pregnancies were associated with an increased risk of  cardiovascular diseases , including  acute kidney injury  and  arrhythmia . Assisted conception pregnancies were also associated with a higher risk of  caesarean delivery  and  premature birth . [ 27 ] [ 28 ]


In theory, ART can solve almost all reproductive problems, except for severe pathology or the absence of a uterus (or womb), using specific gamete or embryo donation techniques. However, this does not mean that all women can be treated with assisted reproductive techniques, or that all women who are treated will achieve pregnancy.


As a result of the 1992 Fertility Clinic Success Rate and Certification Act, the CDC is required to publish the annual ART success rates at U.S. fertility clinics. [ 29 ]  Assisted reproductive technology procedures performed in the U.S. has over than doubled over the last 10 years, with 140,000 procedures in 2006, [ 30 ]  resulting in 55,000 births. [ 30 ]


In  Australia , 3.1% of births in the late 2000's are a result of ART. [ 31 ]


The most common reasons for discontinuation of fertility treatment have been estimated to be: postponement of treatment (39%), physical and psychological burden (19%), psychological burden (14%), physical burden (6.32%), relational and personal problems (17%), personal reasons (9%), relational problems (9%), treatment rejection (13%) and organizational (12%) and clinic (8%) problems. [ 32 ]


Many Americans do not have  insurance  coverage for fertility investigations and treatments. Many states are starting to mandate coverage, and the rate of use is 278% higher in states with complete coverage. [ 33 ]


There are some health insurance companies that cover diagnosis of infertility, but frequently once diagnosed will not cover any treatment costs. [ citation needed ]


Approximate treatment/diagnosis costs in the United States, with inflation, as of 2023 (US$):


Another way to look at costs is to determine the expected cost of establishing a pregnancy. Thus, if a clomiphene treatment has a chance to establish a pregnancy in 8% of cycles and costs $780, the expected cost is $9,400 to establish a pregnancy, compared to an IVF cycle (cycle fecundity 40%) with a corresponding expected cost of $46,800 ($18,700 × 40%). [ citation needed ]


For the community as a whole, the cost of IVF on average pays back by 700% by tax from future employment by the conceived human being. [ 34 ]


In  Europe , 157,500 children were born using assisted reproductive technology in 2015, according to the  European Society of Human Reproduction and Embryology  (ESHRE). [ 35 ]  But there are major differences in legislation across the Old Continent.
A  European directive  fixes standards concerning the use of human tissue and cells, [ 37 ]  but all ethical and legal questions on ART remain the prerogative of  EU member states .


Across Europe, the legal criteria per availability vary somewhat. [ 39 ]  In 11 countries all women may benefit; in 8 others only heterosexual couples are concerned; in 7 only single women; and in 2 ( Austria  and  Germany ) only lesbian couples.
 Spain  was the first European country to open ART to all women, in 1977, the year the first sperm bank was opened there. In  France , the right to ART is accorded to all women since 2019. In the last 15 years, legislation has evolved quickly. For example,  Portugal  made ART available in 2006 with conditions very similar to those in France, before amending the law in 2016 to allow lesbian couples and single women to benefit.  Italy  clarified its uncertain legal situation in 2004 by adopting Europe's strictest laws: ART is only available to heterosexual couples, married or otherwise, and sperm donation is prohibited.


Today, 21 countries provide partial public funding for ART treatment. The seven others, which do not, are  Ireland ,  Cyprus ,  Estonia ,  Latvia ,  Luxembourg ,  Malta , and  Romania .
Such subsidies are subject to conditions, however. In  Belgium , a fixed payment of €1,073 is made for each full cycle of the IVF process. The woman must be aged under 43 and may not carry out more than six cycles of ART. There is also a limit on the number of transferable embryos, which varies according to age and the number of cycles completed.
In France, ART is subsidized in full by national health insurance for women up to age 43, with limits of 4 attempts at IVF and 6 at artificial insemination.
 Germany  tightened its conditions for public funding in 2004, which caused a sharp drop in the number of ART cycles carried out, from more than 102,000 in 2003 to fewer than 57,000 the following year. Since then the figure has remained stable.


17 countries limit access to ART according to the age of the woman. 10 countries have established an upper age limit, varying from 40 ( Finland ,  Netherlands ) to 50 (including Spain,  Greece  and Estonia).
Since 1994, France is one of a number of countries (including Germany, Spain, and the UK) which use the somewhat vague notion of "natural age of procreation". In 2017, the steering council of France's Agency of Biomedicine established an age limit of 43 for women using ART.
10 countries have no age limit for ART. These include Austria,  Hungary , Italy and  Poland .


Most European countries allow donations of gametes by third parties. But the situations vary depending on whether sperm or eggs are concerned. Sperm donations are authorized in 20 EU member states; in 11 of them anonymity is allowed. Egg donations are possible in 17 states, including 8 under anonymous conditions.
On 12 April, the  Council of Europe  adopted a recommendation which encourages an end to anonymity. [ 40 ]  In the UK, anonymous sperm donations ended in 2005 and children have access to the identity of the donor when they reach adulthood.
In France, the principle of anonymous donations of sperm or embryos is maintained in the law of bioethics of 2011, but a new bill under discussion may change the situation. [ 41 ]


In the United Kingdom, all patients have the right to preliminary testing, provided free of charge by the  National Health Service  (NHS). However, treatment is not widely available on the NHS and there can be long waiting lists. Many patients therefore pay for immediate treatment within the NHS or seek help from private clinics.


In 2013, the  National Institute for Health and Care Excellence  (NICE) published new guidelines about who should have access to IVF treatment on the NHS in England and Wales. [ 42 ]


The guidelines say women aged between 40 and 42 should be offered one cycle of IVF on the NHS if they have never had IVF treatment before, have no evidence of low ovarian reserve (this is when eggs in the ovary are low in number, or low in quality), and have been informed of the additional implications of IVF and pregnancy at this age. However, if tests show IVF is the only treatment likely to help them get pregnant, women should be referred for IVF straight away.


This policy is often modified by local  Clinical Commissioning Groups , in a fairly blatant breach of the  NHS Constitution for England  which provides that patients have the right to drugs and treatments that have been recommended by NICE for use in the NHS. For example, the Cheshire, Merseyside and West Lancashire Clinical Commissioning Group insists on additional conditions: [ 43 ]


Some treatments are covered by  OHIP  (public health insurance) in Ontario and others are not. Women with bilaterally blocked fallopian tubes and are under the age of 40 have treatment covered but are still required to pay test fees (around CA$3,000–4,000). Coverage varies in other provinces. Most other patients are required to pay for treatments themselves. [ 44 ]


Israel's national health insurance, which is mandatory for all Israeli citizens, covers nearly all fertility treatments. IVF costs are fully subsidized up to the birth of two children for all Israeli women, including single women and lesbian couples. Embryo transfers for purposes of gestational surrogacy are also covered. [ 45 ]


On 27 January 2009, the  Federal Constitutional Court  ruled that it is unconstitutional, that the health insurance companies have to bear only 50% of the cost for IVF. [ 46 ]  On 2 March 2012, the  Federal Council  has approved a draft law of some federal states, which provides that the federal government provides a subsidy of 25% to the cost. Thus, the share of costs borne for the pair would drop to just 25%. [ 47 ]  Since July 2017, assisted reproductive technology is also allowed for married lesbian couples, as German parliament allowed  same-sex marriages in Germany .


In July 2020, the  French Parliament  allowed assisted reproductive technology also for lesbian couples and single women. [ 48 ] [ 49 ]


Cuban sources mention that assisted reproduction is completely legal and free in the country. [ 50 ] [ 51 ]


The Government of India has notified the Surrogacy (Regulation) Act 2021 and the Assisted Reproductive Technology (Regulation) Act 2021 [ 52 ]  to regulate the practice of ART. Prior to that, the National Guidelines for Accreditation, Supervision and Regulation of ART Clinics in India published by the Ministry for Health and Family Welfare, Government of India in the year 2005 was governing the field. [ 53 ]  Indian law recognises the right of a single woman, who is a major, to have children through ART. [ 54 ]


Some couples may find it difficult to stop treatment despite very bad prognosis, resulting in futile therapies. This has the potential to give ART providers a difficult decision of whether to continue or refuse treatment. [ 55 ]


Some assisted reproductive technologies have the potential to be harmful to both the mother and child, posing a psychological and/or physical health risk, which may impact the ongoing use of these treatments.


In Israel, there is research supporting using ART, including recycled lab materials from the IVF process, to help women work through some of these mixed emotions. [ 56 ] [ 57 ] [ 58 ] [ 59 ]


Films and other fiction depicting emotional struggles of assisted reproductive technology have had an upswing in the latter part of the 2000s decade, although the techniques have been available for decades. [ 60 ]  As ART becomes more utilized, the number of people that can relate to it by personal experience in one way or another is growing. [ 60 ]


For specific examples, refer to the fiction sections in individual subarticles, e.g.  surrogacy ,  sperm donation  and  fertility clinic .


In addition,  reproduction and pregnancy in speculative fiction  has been present for many decades.


25 July 1978,  Louise Brown  was born; this was the first successful birth of a child after  IVF  treatment. The procedure took place at Dr Kershaw's Cottage Hospital (now Dr Kershaw's Hospice) in Royton, Oldham, England.  Patrick Steptoe  (gynaecologist) and  Robert Edwards (physiologist)  worked together to develop the IVF technique. [ 61 ]  Steptoe described a new method of egg extraction and Edwards were carrying out a way to fertilise eggs in the lab. Robert G. Edwards was awarded the  Nobel Prize in Physiology or Medicine  in 2010, but not Steptoe because the Nobel Prize is not awarded posthumously. [ 62 ]


The first successful birth by ICSI ( Intracytoplasmic sperm injection ) took place on 14 January 1992. The technique was developed by  Gianpiero D. Palermo  at the  Vrije Universiteit Brussel , in the Center for Reproductive Medicine in Brussels. Actually, the discovery was made by a mistake when a spermatozoid was put into the cytoplasm. [ 63 ]


This article incorporates text from a  free content  work. Licensed under CC BY 4.0. Text taken from  How does assisted reproductive technology work in Europe? , Orlane Jézéquélou/Alternatives Economiques, EDJNet.


Child harvesting  or  baby harvesting  refers to the systematic sale of  human children , typically for  adoption  by families in the  developed world , but sometimes for other purposes, including  trafficking . The term covers a wide variety of situations and degrees of economic, social, and physical coercion. Child harvesting programs or the locations at which they take place are sometimes referred to as  baby factories  or  baby farms .


After a child is obtained through differing methods mentioned below, the identity of the child or the parent or both are altered in a process known as  child laundering .


Women can become pregnant with the intent of selling their babies, willingly or forcibly. The facilities where the babies are delivered and sold are known as "baby factories" or "baby breeding farms". They might be disguised as maternity homes, orphanages, clinics and small scale factories. [ 1 ]  The practice is often driven by poverty. In some cases there is overlap with  commercial surrogacy , where the male partner buying the baby also provides the sperm. [ 2 ]  Illegal street clinics such as this exist in  Kenya . [ 3 ]  A company called Baby101 had a baby factory in Thailand busted by police in 2011. [ 2 ]  Baby factories operating through social media were documented in Malaysia in 2016. [ 4 ]  Most of the discovered baby factories are found in Southern Nigeria, with high incidence in  Ondo ,  Ogun ,  Imo ,  Akwa Ibom   Abia  and  Anambra . [ 5 ]


Baby factories have sometimes tricked or abducted women to be raped in order to sell their babies. [ 6 ] [ 7 ]  In 2008, a network of baby factories claiming to be  orphanages , was revealed in  Enugu ,  Enugu State  ( Nigeria ), by police raids. [ 8 ] [ 9 ] [ 10 ]  In June 2011, in  Aba, Nigeria , 32 pregnant girls were freed from a baby farm that claimed to help pregnant teenagers but would then force them to give their babies. [ 11 ] [ 12 ] [ 13 ] [ 14 ]  In October 2011, seventeen pregnant women (thirty according to some sources [ 15 ] [ 16 ] ) were found in  Ihiala ,  Anambra , in a hospital of the  Iheanyi Ezuma Foundation . [ 17 ]  Five more baby factories were discovered in 2013, and eight more were discovered in 2015. [ 5 ]


Organized rings in  Nairobi  are known to abduct the children of  homeless  mothers. This is usually while the families are sleeping on the street but also through gaining the trust of the mother. [ 3 ]  In 1990s, it was rumored that child snatchers commonly roamed the country in Guatemala, which has lax laws regulating adoption. [ 18 ]  In the 1980s, staff in some hospitals in  Sri Lanka  were involved in rackets of kidnapping newborns for international adoptions. They informed the biological mothers that the newborns had died and paid other women to act as the real mothers. [ 19 ]  The state can also be involved in such schemes. During the  One Child Policy  in China, when women were only allowed to have one child, local governments would often allow the woman to give birth and then they would take the baby away. Child traffickers, often paid by the government, would sell the children to orphanages that would arrange international adoptions worth tens of thousands of dollars, turning a profit for the government. [ 20 ]


Women who have a child or are  pregnant  with a child which they feel they are unable or unwilling to care for have been approached to instead deliver the baby to be sold to those looking for a child. The stigmatization of teenage pregnancy and lack of abortion access [ 5 ]  have been cited as driving factors.  Immigrant   sex workers  in  Malaysia  who get pregnant have entered into such exchanges as it is illegal for them to bear children. [ 4 ]  Those approaching them are often healthcare professionals. Police broke such a scheme in a hospital in  Gwailor  in India in 2016. [ 21 ]  Police broke such a scheme in a hospital in Egypt in 2012. [ 22 ]


Child harvesting is particularly associated with and prevalent in some  international adoption  markets. [ 23 ] [ 24 ] [ 25 ]  Cited factors driving this are a stigmatization of childless couples, the costs of  assisted reproductive technology  such as  in vitro fertilization , and difficulties in adoption such as cultural acceptance, legality,  [ 22 ]  or administrative difficulty. [ 26 ]


Child harvesting may also be involved in situations in which children are trafficked to provide  slave labor . [ 14 ] [ 8 ]  This could include in  begging  syndicates, [ 4 ]   plantations ,  mines ,  factories , as  domestic workers , or as  sex workers . [ 14 ] [ 8 ]


There have been relatively few allegations that some child harvesting programs provide infants to be  tortured  or  sacrificed  in  black magic  or  witchcraft  rituals; this seems to be a concern in Nigeria. [ 12 ] [ 17 ] [ 13 ] [ 27 ]


Childlessness  is the state of not having  children . Childlessness may have personal, social or political significance.


Childlessness, which may be by choice or circumstance, is distinguished from  voluntary childlessness , also called being "childfree", which is voluntarily having no children, and from  antinatalism , wherein childlessness is promoted.


Types of childlessness can be classified into several categories: [ 1 ]


The first three categories are often grouped under the label "involuntary childlessness". The latter category is often called " voluntary childlessness ", also described as being "childfree", occurring when one decides not to reproduce.


The analysis of the three broad categories of childlessness (natural sterility, social sterility, voluntary childlessness) outlined above helps to understand how it has changed over the last century in the United States. [ 2 ]  At the end of the 19th century, income and education levels were low. This made levels of social sterility very high. In addition to the causes mentioned above, the  Spanish Influenza  epidemics meant that pregnant women who were infected were particularly vulnerable to miscarriages. The  Great Depression  also impoverished these generations, for whom voluntary childlessness was almost absent. On the whole, the rates of childlessness for married women born between 1871 and 1915 fluctuated between 15 and 20 percent. The rise in both education and overall income allowed subsequent generations to escape from situations where couples were “constrained” from having children, and rates of childlessness began to fall. Over time, the nature of childlessness changed, becoming more and more the chosen outcome of some educated women. A low level of childlessness of 7% was achieved by the generation of the baby boom. It started to rise again for the subsequent generations, with 12 percent of women born in 1964-68 remaining childless.


From 2007 to 2011, the fertility rate in the U.S. declined 9%, the  Pew Research Center  reporting in 2010 that the birth rate was the lowest in U.S. history and that childlessness rose across all racial and ethnic groups to about 1 in 5 versus 1 in 10 in the 1970s. [ 5 ]  The  CDC  released statistics in the first quarter of 2016 confirming that the U.S. fertility rate had fallen to its lowest point since record keeping started in 1909: 59.8 births per 1,000 women, half its high of 122.9 in 1957. [ 6 ]  Even taking the falling fertility rate into account, the  U.S. Census Bureau  still projected that the U.S. population would increase from 319 million (2014) to 400 million by 2051. [ 6 ]


In a paper presented at a 2013  United Nations Economic Commission for Europe  work session on Demographic Projections, Swedish statisticians reported that since the 2000s, childlessness had decreased in Sweden and marriages had increased. It had also become more common for couples to have a third child suggesting that the nuclear family was no longer in decline in Sweden. [ 7 ] : 10


The number of people over 50 in the UK without adult children in 2023 was reported to be 20 percent. [ 8 ]


Reasons for childlessness include, but are not limited to, the following:


Personal choice, that is, having the physical, mental, and financial capability to have children but choosing not to (that is,  voluntary childlessness ), also called being "childfree".


Infertility , the inability of a person or persons to conceive, due to complications related to either or both a woman or a man. This is regarded as the most prominent reason for involuntary childlessness. Biological causes of infertility vary because many organs of both sexes must function properly for conception to take place. Infertility also affects people who are unable to conceive a second or subsequent pregnancy. This is called secondary infertility. [ 9 ]


Obstetric or gynaecological problems , including physical injury caused by a previous pregnancy. [ 10 ]


Mental-health  difficulties, such as impairment of  executive functioning , that prevent a would-be parent from being able to properly raise a child.


Chronic illness/disability: Many serious chronic health conditions put the health of the mother and baby at undue risk if she were to become pregnant. These women are advised not to become pregnant. Some chronic health issues/disabilities obviate a parent from being able to care for a child.


Practical difficulties involving features of one's environment:


Unwillingness of one's partner, where existent, to conceive or raise children (includes partners who are unwilling to adopt children despite being biologically infertile, of the same biological sex, or physically absent).


The death of all of a person's already-conceived children either before birth (as with  miscarriage  and  stillbirth ) or after birth (as with  infant  and  child mortality ) coupled with a person's not having yet had other children for reasons ranging from physical or  emotional exhaustion  to having passed childbearing age. Infant and child death can happen for any number of reasons, usually medical or environmental, such as biological malformations, maternal complications, accident or other injury, and disease. Both the existence of many of these causes and the severity of their harm when present can be mitigated by ensuring that the infant's or child's environment features resources ranging from parenting and safety information to pre-, peri-, and postnatal medical care for mother and child.


Medical interventions may be available to some individuals or couples to treat involuntary childlessness. Some options include  artificial insemination ,  intracytoplasmic sperm injection  (ICSI) and  in vitro fertilization . Artificial insemination is the process in which sperm is collected via  masturbation  and inserted into the uterus immediately after ovulation. Intracytoplasmic sperm injection is a more recent technique that involves injecting a single sperm directly into an egg, the egg is then placed in the uterus by  in vitro fertilization . In vitro fertilization (IVF) is the process in which a mature  ovum  is surgically removed from a women's ovary, placed in a medium with sperm until fertilization occurs and then placed in the women's uterus. About 50,000 babies in the United States are conceived this way and are sometimes referred to as "test-tube babies." [ 13 ]  Other forms of assisted reproductive technology include, gamete intrafallopian transfer (GIFT) and  zygote intrafallopian transfer  (ZIFT).
Fertility drugs also may improve the chances of conception in women.


For those facing social infertility (such as single individuals or same-sex couples) as well as heterosexual couples with medical infertility, other options include surrogacy and adoption.  Surrogacy , in this case a surrogate mother, is the process in which a woman becomes pregnant (usually by artificial insemination or surgical implantation of a fertilized egg) for the purpose of carrying the fetus to term for another individual or couple. Another option may be  adoption ; to adopt is to take voluntarily (a child of other parents) as one's own child.


All forms of contraception have played a role in voluntary childlessness over time, but the invention of reliable oral contraception contributed profoundly to changes in societal ideas and norms. Voluntary childlessness, resulting from contraception has influenced women's health, laws and policies, interpersonal relationships, feminist issues, and sexual practices among adults and adolescents. [ 14 ]


The availability of oral contraception during the late 1900s was directly related to the women's rights movement by establishing, for the first time, a mass distribution of a way to control fertility. The so-called " pill " gave women the opportunity to make different life choices they may not previously have been able to make, such as for example, furthering their career. This led to monumental changes in the current gender and family roles. [ citation needed ]


Margaret Sanger , an activist in 1914, was an important figure during the reproductive rights movement. She coined the term "birth control" and opened the first birth control clinic in the U.S. Sanger collaborated with many others to make the first oral contraception possible, these persons include:  Gregory Pincus ,  John Rock ,  Frank Colton , and  Katherine McCormick . The pill was approved by the  FDA  (Food and Drug Administration) for contraceptive use in the year 1960 and although it was controversial, it remained the most popular form of birth control in the U.S. until 1967 when there was a rise in publicity about the possible health risks associated with the pill; consequently sales dropped twenty-four percent. In the year 1988 the original high-dose pill was taken off the market and replaced with a low-dose pill that was considered to have less risks and some health benefits. [ 15 ]


Before conception was well understood, childlessness was usually blamed on the woman and this in itself added to the high level of negative emotional and social effects of childlessness. “Some wealthy families also adopted children, as a means of providing heirs in cases of childlessness or where no sons had been born.” [ 16 ]  The monetary incentives offered by Westerners' desire for children is so strong that a commercial market in  child laundering  exists.


People trying to cope with involuntary childlessness may experience symptoms of distress that are similar to those experienced by bereaved people, such as health problems, anxiety and depression. [ 17 ]


Specific instances of childlessness, especially in cases of  royal succession , but more generally for people in positions of power or influence, have had enormous impacts on politics, culture and society. In many cases, a lack of a male child was also considered a type of childlessness, since male children were needed as heirs to property and titles. Examples of historical impacts of actual or potential childlessness include:


Socially, childlessness has also resulted in financial stress and sometimes ruin in societies which depend on their offspring to contribute economically and to support other members of the family or tribe. “In agricultural societies about 20 per cent of all couples would not have children because of problems for at least one of the partners. Worry about assuring the desired birth rate could become an important part of family life … even after a first child was born. … In agricultural societies up to half of all children born would die within two years … (Excess surviving children could among other things, be sent to childless families to provide labour there, reducing upkeep demands at home.) When a population disaster hit – like war or major disease – higher birth rates might briefly be feasible to fill out community ranks.” [ 20 ]


In the 20th and 21st centuries, when control over conception became reliable in some countries, childlessness is having an enormous impact on national planning and financial planning. [ 21 ]  In societies where child-bearing is a sign of a high libido, childlessness may be viewed as a sign of low libido. [ 22 ]  They may also be disparaged with terms like  genetic dead end . [ 23 ]


In some countries, even those with state health and social care services, children often support elderly family members either by becoming their full or part time carers, or by, for example, accompanying them to medical appointments, helping with cleaning and shopping, taking care of intimate personal care tasks or by looking after their finances. If national health and care services dwindle due to decreased funding or lack of staff, and if the numbers of people without children nearby increase, the statistics for those left without help and support as they age, are set to soar. [ 8 ]


In a society that encourages and promotes parenthood, with its current social norms and culture, childlessness can be stigmatizing. Pronatalism, the idea couples should reproduce and want to reproduce remains widespread in North America, contrary to most European cultures. [ 24 ]  Women in Australia, [ 25 ]  and both men and women in the UK [ 26 ]  have reported facing stigma and  social exclusion  because of their childlessness.


Childlessness may be considered deviant behavior in marriage and this may lead to adverse effects on the relationship of the couple, as well as their individual identities when pertaining to the lack of children being involuntary. For persons that consider that becoming parents was a critical process of their adult family life, a "transition" as Rossi deems it must take place. This transition is from the anticipated parenthood to an unwanted status of non-parenthood. Such a transition may require the individual to readjust their perspective of self or relationship role with their significant other. [ 27 ]


The  dartos fascia ,  dartos tunic  or simply  dartos  is a layer of  connective tissue  found in the  penile shaft ,  foreskin  and  scrotum . [ 1 ]  The penile portion is referred to as the  superficial fascia of penis  or the  subcutaneous tissue of penis , [ 2 ]  while the scrotal part is the dartos proper. In addition to being continuous with itself between the scrotum and the penis, it is also continuous with  Colles' fascia  of the perineum and  Scarpa's fascia  of the abdomen. [ 1 ]


The dartos lies just below the skin, which places it just superficial to the external spermatic fascia in the scrotum and to  Buck's fascia  in the penile shaft. In the scrotum, it consists mostly of  smooth muscle . [ 3 ]  The tone of this smooth muscle is responsible for the wrinkled (rugose) appearance of the scrotum. [ 1 ]  In females, the same muscle fibers are less well developed and termed  dartos muliebris , lying beneath the skin of the  labia majora . The dartos fascia receives innervation from  postganglionic sympathetic nerve fibers  arriving via the  ilioinguinal nerve  and the  posterior scrotal nerve .


In the penis, the loose attachment of the dartos fascia to Buck's fascia is responsible for the high degree of mobility of the penile skin over the underlying tissue. [ 1 ]  It is also responsible for carrying the blood supply of the penile skin, a longitudinally-coursing anastomotic network of vessels that arise from the external pudendal vessels. [ 1 ]


In the scrotum, the dartos fascia acts to regulate the  temperature  of the  testicles , which promotes  spermatogenesis . It does this by expanding or contracting to wrinkle the scrotal skin.


The dartos muscle works in conjunction with the  cremaster muscle  to elevate the  testis  but should not be confused with the  cremasteric reflex .


The dartos fascia keeps the foreskin close to the glans penis throughout life. In infancy, the dartos fascia operates as a one-way check valve at the tip of the foreskin, allowing urine to pass out, but prohibiting the entry of foreign matter and pathogens.


There is an increase in elastic fibers with increasing maturity that allows the foreskin to become retractable by adulthood and glide freely back and forth.


Etymology:


Some dartos-related terms:


A  designer baby  is a baby whose  genetic makeup  has been selected or altered, often to exclude a particular  gene  or to remove genes associated with disease. [ 1 ] [ 2 ]  This process usually involves analysing a wide range of human  embryos  to identify genes associated with particular  diseases  and characteristics, and selecting embryos that have the desired genetic makeup; a process known as  preimplantation genetic diagnosis . [ 3 ]  Screening for single genes is commonly practiced, and polygenic screening is offered by a few companies. [ 4 ]  Other methods by which a baby's genetic information can be altered involve directly  editing the genome  before birth, which is not routinely performed and only one instance of this is known to have occurred as of 2019, where Chinese twins  Lulu and Nana  were edited as embryos, causing widespread criticism. [ 5 ]


Genetically altered embryos can be achieved by introducing the desired genetic material into the embryo itself, or into the  sperm  and/or  egg  cells of the parents; either by  delivering the desired genes directly into the cell  or using gene-editing technology. This process is known as  germline engineering  and performing this on embryos that will be brought to term is typically prohibited by law. [ 6 ]  Editing embryos in this manner means that the genetic changes can be  carried down to future generations , and since the technology concerns editing the genes of an unborn baby, it is considered controversial and is subject to ethical debate. [ 7 ]  While some scientists condone the use of this technology to treat disease, concerns have been raised that this could be translated into using the technology for cosmetic purposes and  enhancement of human traits . [ 8 ]


Pre-implantation genetic diagnosis (PGD or PIGD) is a procedure in which embryos are screened prior to  implantation . The technique is used alongside  in vitro  fertilisation  (IVF) to obtain embryos for evaluation of the genome – alternatively, ovocytes can be screened prior to  fertilisation . The technique was first used in 1989. [ 9 ]


PGD is used primarily to select embryos for implantation in the case of possible  genetic defects , allowing identification of  mutated  or disease-related  alleles  and selection against them. It is especially useful in embryos from parents where one or both carry a  heritable disease . PGD can also be used to select for embryos of a certain sex, most commonly when a disease is more strongly associated with one sex than the other (as is the case for  X-linked disorders  which are more common in males, such as  haemophilia ). Infants born with traits selected following PGD are sometimes considered to be designer babies. [ 10 ]


One application of PGD is the selection of ' saviour siblings ', children who are born to provide a  transplant  (of an organ or group of cells) to a sibling with a usually life-threatening disease. Saviour siblings are conceived through IVF and then screened using PGD to analyze genetic similarity to the child needing a transplant, to reduce the risk of  rejection . [ 11 ]


Embryos for PGD are obtained from IVF procedures in which the oocyte is artificially fertilised by sperm.  Oocytes  from the woman are harvested following  controlled ovarian hyperstimulation  (COH), which involves fertility treatments to induce production of multiple oocytes. After harvesting the oocytes, they are fertilised  in vitro , either during incubation with multiple sperm cells in culture, or  via   intracytoplasmic sperm injection  (ICSI), where sperm is directly injected into the oocyte. The resulting embryos are usually cultured for 3–6 days, allowing them to reach the  blastomere  or  blastocyst  stage. [ 12 ]


Once embryos reach the desired stage of development, cells are biopsied and genetically screened. The screening procedure varies based on the nature of the disorder being investigated.


Polymerase chain reaction  (PCR) is a process in which  DNA  sequences are amplified to produce many more copies of the same segment, allowing screening of large samples and identification of specific genes. [ 13 ]  The process is often used when screening for  monogenic disorders , such as  cystic fibrosis .


Another screening technique,  fluorescent  in situ  hybridisation  (FISH) uses fluorescent probes which specifically bind to highly  complementary sequences  on  chromosomes , which can then be identified using  fluorescence microscopy . [ 14 ]  FISH is often used when screening for chromosomal abnormalities such as  aneuploidy , making it a useful tool when screening for disorders such as  Down syndrome .


Following the screening, embryos with the desired trait (or lacking an undesired trait such as a mutation) are transferred into the mother's  uterus , then allowed to  develop naturally .


PGD regulation is determined by individual countries' governments, with some prohibiting its use entirely, including in  Austria ,  China , and  Ireland . [ 15 ]