There are many determinants of the intention to have children, including:


The  Preference Theory  suggests that a woman's attitudes towards having children are shaped early in life.  Furthermore, these attitudes tend to hold across the life course, and boil down to three main types: career-oriented, family-oriented, and a combination of both work and family. Research shows that family-oriented women have the most children, and work-oriented women have the least, or none at all, although causality remains unclear. [ 1 ]


Preferences can also apply to the sex of the children born, and can therefore influence the decisions to have more children.  For instance, if a couple's preference is to have at least one boy and one girl, and the first two children born are boys, there is a significantly high likelihood that the couple will opt to have another child. [ 1 ]


A survey taken place in 2002 in the United States found that women who reported  religion  as "very important" in their everyday lives had a higher fertility than those reporting it as "somewhat important" or "not important". [ 2 ]


For many religions, religiosity is directly associated with an increase in the intention to have children. [ 2 ]  This appears to be the main means by which religion increases fertility. [ 21 ]  For example, as of 1963,  Catholic  couples generally had intentions to have more children than  Jewish  couples, who in turn, tended to have more children than  Protestant  couples. [ 21 ]  Among Catholics, increased religiosity is associated with the intention to have more children, while on the other hand, increased religiousness among Protestants is associated with the intention to have fewer children. [ 21 ]


It has also been suggested that religions generally encourage lifestyles with fertility factors that, in turn, increase fertility. [ 22 ]  For example,  religious views on birth control  are, in many religions, more restrictive than secular views, and such religious restrictions have been associated with increased fertility. [ 23 ]


Religion sometimes modifies the fertility effects of education and income.  Catholic education  at the university level and the secondary school level is associated with higher fertility, even when accounting for the confounding effect that higher religiosity leads to a higher probability of attending a religiously affiliated school. [ 21 ]  Higher income is also associated with slightly increased fertility among Catholic couples, however, is associated with slightly decreased fertility among Protestant couples. [ 21 ]


Parents' religiosity is positively associated with their children's fertility. Therefore, more religious parents will tend to increase fertility. [ 1 ]


A 2020 study found that the relation between religiosity and fertility was driven by the lower aggregate fertility of secular individuals. While religiosity did not prevent low fertility levels (as some highly religious countries had low fertility rates), secularism did prevent high fertility (as no highly secular country had high fertility rates). Societal level secularism was also a better predictor of religious individuals' fertility than secular individuals, largely due to the effects of cultural values on reproduction, gender and personal autonomy. [ 24 ]


The transmission of values from parents to offspring ( nurture ) has been a core area of fertility research.  The assumption is that parents transmit these  family values , preferences, attitudes and religiosity to their children, all of which have long-term effects analogous to genetics.  Researchers have tried to find a causal relationship between, for example, the number of parents' siblings and the number of children born by the parents own children (a quantum effect), or between the age of the first birth of the parents' generation and age of first birth of any of their own children (a tempo effect). [ 1 ]


Most studies concerning tempo focus on teenage mothers and show that having had a young mother increases the likelihood of having a child at a young age. [ 1 ]


In  high-income countries , the number of children a person has strongly correlates with the number of children that each of those children will eventually have. [ 25 ] [ non-primary source needed ] [ 1 ]


Danish data from  non-identical twins  growing up in the same environment compared to  identical twins  indicated that genetic influences in themselves largely override previously shared environmental influences. [ 1 ]  The  birth order  does not seem to have any effect on fertility. [ 21 ]


Other studies, however, show that this effect can be balanced by the child's own attitudes that result from personal experiences, religiosity, education, etc. So, although the mother's preference of family size may influence that of the children through early adulthood, [ 25 ]  the child's own attitudes then take over and influence fertility decisions. [ 1 ]


The effect of cohabitation on fertility varies across countries. [ 1 ]


In the US cohabitation is generally associated with lower fertility. [ 1 ]   However, another study found that cohabiting couples in France have equal fertility as married ones. [ 1 ]  Russians have also been shown to have a higher fertility within cohabitation. [ 26 ]


Survey data from 2003 in  Romania  showed that marriage equalized the  total fertility rate  among both highly educated and limited-education people to approximately 1.4. Among those cohabiting, on the other hand, a lower level of education increased the fertility rate to 1.7, and a higher level of education decreased it to 0.7. [ 27 ]  Another study found that Romanian women with little education have about equal fertility in marital and cohabiting partnerships. [ 28 ]


A study of the United States, and multiple countries in Europe, found that women who continue to cohabit after giving birth have a significantly lower probability of having a second child than married women in all countries, except those in Eastern Europe. [ 29 ]


Data from the  Generations and Gender Survey  showed that women with living mothers had earlier first births, while a mother's death early in a daughter's life correlated with a higher probability of childlessness. On the other hand, the survival of fathers had no effect on either outcome. Co-residence with parents delayed first births and resulted in lower total fertility and higher probability of childlessness. This effect is even stronger for poor women. [ 5 ]


Social support from the extended family and friends can help a couple decide to have a child, or another one.


Studies mainly in ex-communist Eastern European countries have associated increased fertility with increased  social capital  in the form of personal relationships, goods, information, money, work capacity, influence, power, and personal help from others. [ 1 ]


Research in the U.S. shows that the extended family willing to provide support becomes a "safety net".  This is particularly important for single mothers and situations involving partnership instability. [ 1 ]


Total fertility rates  are higher among women in  rural areas  than among women in  urban areas , as evidenced from  low-income , [ 30 ]  middle-income [ 30 ]  and  high-income countries . [ 1 ]  Field researchers have found that fertility rates are high and remain relatively stable among rural populations. Little evidence exists to suggest that high-fertility parents appear to be economically disadvantaged, further strengthening the fact that total fertility rates tend to be higher among women in rural areas. [ 31 ]  On the other hand, studies have suggested that a higher  population density  is associated with decreased fertility rates. [ 32 ]  It is shown through studies that fertility rates differ between regions in ways that reflect the opportunity costs of child rearing. In a region with high population density, women restrain themselves from having many children due to the costs of living, therefore lowering the fertility rates. [ 32 ]  Within urban areas, people in  suburbs  are consistently found to have higher fertility. [ 1 ]  Some research indicates that population density may explain up to 31% of the variance in fertility rates, although the effect of population density on fertility can be moderated by other factors such as environmental conditions, religiosity and social norms. [ 33 ]


Many studies have attempted to determine the causal link between government policies and fertility. However, as this article suggests, there are many factors that can potentially affect decisions to have children, how many to have, and when to have them, and separating these factors from effects of a particular government policy is difficult. Making this even more difficult is the time lag between government policy initiation and results. [ 1 ]


The purpose of these programs is to reduce the  opportunity cost  of having children, either by increasing family income or reducing the cost of children. [ 8 ]    One study has found a positive effect on number of children during life due to family policy programs that make it easier for women to combine family and employment.  Again, the idea here is to reduce the opportunity cost of children.  These positive results have been found in Germany, Sweden, Canada, and the US. [ 34 ]


However, other empirical studies show that these programs are expensive and their impact tends to be small, so currently there is no broad consensus on their effectiveness in raising fertility. [ 4 ]


Other factors associated with increase of fertility include:


Fertility is declining in advanced societies because couples are having fewer children or none at all, or they are delaying childbirth beyond the woman's most fertile years.  The factors that lead to this trend are complex and probably vary from country to country. [ 8 ]


Increased  income  and  human development  are generally associated with decreased fertility rates. [ 38 ]  Economic theories about declining fertility postulate that people earning more have a higher  opportunity cost  if they focus on childbirth and parenting rather than continuing their careers, [ 1 ]  that women who can economically sustain themselves have less incentive to become married, [ 1 ]  and that higher income parents value quality over quantity and so spend their resources on fewer children. [ 1 ]


On the other hand, there is some evidence that with rising economic development, fertility rates drop at first, but then begin to rise again as the level of social and economic development increases, while still remaining below the  replacement rate . [ 39 ] [ 40 ]


While some researchers cite economic factors as the main driver of fertility decline, socio-cultural theories focus on changes in values and attitudes toward children as being primarily responsible.  For example, the  Second Demographic Transition  reflects changes in personal goals, religious preferences, relationships, and perhaps most important, family formations. [ 8 ]  Also,  Preference Theory  attempts to explain how women's choices regarding work versus family have changed and how the expansion of options and the freedom to choose the option that seems best for them are the keys to recent declines in  TFR . [ 8 ]


A comparative study in Europe found that family-oriented women had the most children, work-oriented women had fewer or no children, and that among other factors, preferences play a major role in deciding to remain childless. [ 1 ]


Another example of this can be found in Europe and in  post-Soviet states , where values of increased autonomy and independence have been associated with decreased fertility. [ 1 ]


Results from research which attempts to find causality between education and fertility is mixed. [ 1 ]  One theory holds that higher educated women are more likely to become career women. Also, for higher educated women, there is a higher opportunity cost to bearing children. Both would lead higher educated women to postpone marriage and births. [ 1 ]  However, other studies suggest that, although higher educated women may postpone marriage and births, they can recuperate at a later age so that the impact of higher education is negligible. [ 1 ]


In the  United States , a large survey found that women with a bachelor's degree or higher had an average of 1.1 children, while those with no high school diploma or equivalent had an average of 2.5 children. [ 3 ]  For men with the same levels of education, the number of children was 1.0 and 1.7, respectively. [ 3 ] [ non-primary source needed ]


In  Europe , on the other hand, women who are more educated eventually have about as many children as do the less educated, but that education results in having children at an older age. [ 1 ]  Likewise, a study in  Norway  found that better-educated males have a decreased probability of remaining childless, although they generally became fathers at an older age. [ 41 ]


Catholic education  at the university level and, to a lesser degree, at the secondary school level, is associated with higher fertility, even when accounting for the confounding effect that higher religiosity among Catholics leads to a higher probability of attending a religiously affiliated school. [ 21 ]


The level of a country's development often determines the level of women's education required to affect fertility.  Countries with lower levels of development and gender equivalence are likely to find that a higher level of women's education, greater than secondary level, is required to affect fertility. Studies suggest that in many sub-Saharan African countries fertility decline is linked to female education. [ 42 ] [ 43 ]  Having said this, fertility in undeveloped countries can still be significantly reduced in the absence of any improvement in the general level of formal education. For example, During the period 1997-2002 (15 years), fertility in Bangladesh fell by almost 40%, despite the fact that literacy rates (especially those of women) did not increase significantly. This reduction has been attributed to that country's family planning program, which could be called a form of informal education. [ 44 ]


China  and  India  have the oldest and the largest  human population control  programs in the world. [ 45 ]  In China, a  one-child policy  was introduced between 1978 and 1980, [ 46 ]  and began to be formally phased out in 2015 in favor of a  two-child policy . [ 47 ]  The  fertility rate  in China fell from 2.8 births per woman in 1979 to 1.5 in 2010. [ 11 ]  However, the efficacy of the one-child policy itself is not clear, since there was already a sharp reduction from more than five births per woman in the early 1970s, before the introduction of the one-child policy. [ 11 ]  It has thereby been suggested that a decline in fertility rate would have continued even without the strict  antinatalist  policy. [ 48 ]  In 2015 China ended its one child policy, allowing couples to have two children. This was a result of China having a large  dependency ratio  with its ageing population and working force. [ 49 ]


Extensive efforts have been put into  family planning in India . The fertility rate has dropped from 5.7 in 1966 to 2.4 in 2016. [ 50 ] [ 51 ]  Still, India's family planning program has been regarded as only partially successful in controlling fertility rates. [ 52 ]


Increased participation of  women in the workforce  is associated with decreased fertility. A multi-country  panel study  found this effect to be strongest among women aged 20–39, with a less strong but persistent effect among older women as well. [ 10 ] [ non-primary source needed ] [ better source needed ]  International  United Nations  data suggests that women who work because of economic necessity have higher fertility than those who work because they want to do so. [ 53 ]


However, for countries in the  OECD  area, increased female labor participation has been associated with increased fertility. [ 54 ]


Causality analyses indicate that fertility rate influences female labor participation, not the other way around. [ 1 ]


Women who work in nurturing professions such as teaching and health generally have children at an earlier age. [ 1 ]  It is theorized that women often self-select themselves into jobs with a favorable  work–life balance  in order to pursue both motherhood and employment. [ 1 ]


Regarding  age and female fertility , fertility starts at  onset of menses , typically around age 12-13 [ 55 ] [ 56 ] [ 57 ]  Most women become  subfertile  during the early 30s, and during the early 40s most women become  sterile . [ 12 ]


Regarding  age and male fertility , men have decreased pregnancy rates, increased time to pregnancy, and increased infertility as they age, although the correlation is not as substantial as in women. [ 58 ]  When  controlling for  the age of the female partner, comparisons between men under 30 and men over 50 found relative decreases in pregnancy rates between 23% and 38%. [ 58 ]


An Indian study found that couples where the woman is less than one year younger than the man have a total mean
number of children of 3.1, compared to 3.5 when the woman is 7–9 years younger than the man. [ 59 ]


The "contraceptive revolution" has played a crucial role in reducing the number of children (quantum) and postponing child-bearing (tempo). [ 1 ]


Periods of decreased use of  contraceptive pills  due to fears of side effects have been linked with increased fertility in the United Kingdom. [ 1 ]  Introductions of laws that increase access to contraceptives have been associated with decreased fertility in the United States. [ 1 ]  However, short-term decreases in fertility may reflect a  tempo effect  of later childbearing, with individuals using contraceptives catching up later in life. A review of long-term fertility in Europe did not find fertility rates to be directly affected by availability of contraceptives. [ 8 ]


The decision to bear a child in advanced societies generally requires agreement between both partners.  Disagreement between partners may mean that the desire for children of one partner are not realized. [ 1 ]


The last several decades have also seen changes in partnership dynamics.  This has led to a tendency toward later marriages and a rise in unmarried cohabitation. Both of these have been linked to the postponement of parenthood (tempo) and thus reduced fertility. [ 1 ]


20-30% percent of infertility cases are due to  male infertility , 20–35% are due to  female infertility , and 25-40% are due to combined problems. [ 13 ]  In 10–20% of cases, no cause is found. [ 13 ]


The most common cause of  female infertility  is ovulatory problems, which generally manifest themselves by sparse or absent menstrual periods. [ 60 ]   Male infertility  is most commonly caused by deficiencies in the  semen :  semen quality  is used as a surrogate measure of male fecundity. [ 61 ]


The trend of couples forming partnerships and marrying at later ages has been going on for some time. For example, in the US, during the period 1970 to 2006, the average age of first-time mothers increased by 3.6 years, from 21.4 years to 25.0 years. [ 66 ]


Also, fertility postponement has become common in all European countries, including those of the former Soviet Union. [ 67 ]


Nevertheless, delayed childbirth alone is not sufficient to reduce fertility rates: in France despite the average high age at first birth, fertility rate remains close to the 2.1 replacement value. [ 8 ]   The aggregate effects of delayed childbearing tend to be relatively minor, because most women still have their first child well before the onset of infertility. [ 67 ]


The following have been reported, at least in the primary research literature, to have no or uncertain effects.


In the  United States ,  Hispanics , and  African Americans  have earlier and higher fertility than other racial and ethnic groups. In 2009, the teen birth rate for Hispanics between the age 15-19 was roughly 80 births per 1000 women. The teen birth rate for African Americans in 2009 was 60 births per 1000 women and 20 for non Hispanic teens (white). [ 72 ]   According to the United States census, State Health Serve and the CDC, Hispanics accounted for 23% of the birth in 2014 out of the 1,000,000 births in the United States. [ 73 ] [ 3 ] [ non-primary source needed ]


A  regression analysis  on a population in India resulted in the following equation of  total fertility rate , where parameters preceded by a plus were associated with increased fertility, and parameters preceded by a minus were associated with decreased fertility: [ 38 ] [ non-primary source needed ]


Total Fertility Rate = 0.02 ( human development index *) + 0.07 ( infant mortality rate *) − 0.34 ( contraceptive  use) + 0.03 (male age at marriage*) − 0.21 (female age at marriage) − 0.16 (birth interval) − 0.26 (use of improved  water quality ) + 0.03 (male literacy rate*) − 0.01 (female literacy rate*) − 0.30 ( maternal care )


* = Parameter did not reach  statistical significance  on its own


Calder, Vanessa Brown, and Chelsea Follett (August 10, 2023).  Freeing American Families: Reforms to Make Family Life Easier and More Affordable ,  Policy Analysis  no. 955, Cato Institute, Washington, DC.


Annabelle "Anna" Frances Glasier   OBE ,  FFSRH ,  FRCOG   FRSE  is an English  physician  in the field of  reproductive medicine . Glasier is a world expert on  emergency contraception , and her work has been instrumental in making it available in the UK and other countries without medical prescription. [ 1 ]


In 1973, Glasier graduated from the  University of Bristol  with a  BSc . She then attended the  University of Edinburgh  graduating with a  MBChB  in 1976. She specialised in  obstetrics and gynaecology , working under the supervision of  Allan Templeton . She passed her MD in 1983, qualifying as a  doctor . Her thesis was on the hormonal mechanisms underlying lactational infertility. [ 2 ]


In 1989, Glasier became a clinical scientist at the  Medical Research Council  Unit of Reproductive Biology. She held the position of Director of Family Planning and Well Woman Services at  NHS Lothian  from 1990-2010, and was Lead Clinician for Sexual Health. [ 1 ] [ 2 ]  Her research specialities are  reproductive health , and she is globally recognised in the field of  emergency contraception , with her work playing an instrumental role in its deregulation. [ 2 ]


She has worked with international organisations, including the  Population Council  in  New York , and the  World Health Organization , where she chaired the  Human Reproduction Programme ’s Scientific and Technical Advisory Group from 2004 to 2008. [ 2 ]


She is an honorary professor at the  London School of Hygiene and Tropical Medicine  (Department of Public Health and Policy) and the Emeritus Professor in the Centre for Reproductive Health at the  University of Edinburgh . [ 3 ]


Glasier is the daughter of  Phillip Glasier  and sister of  Jemima Parry-Jones , both noted for their work with  birds of prey .


International family planning programs  aim to provide women around the world, especially in developing countries, with contraceptive and reproductive services that allow them to avoid unintended pregnancies and control their reproductive choices.


In 2018, the World Health Organization (WHO) estimated that around 214 million women around the world wanted to avoid pregnancy but were not currently using any method of contraception or family planning. [ 1 ]  Family planning programs, especially in terms of development, seek to promote women making autonomous reproductive choices about the size of their family, the spacing, and overall health of women and children. [ 1 ]  Studies show that reducing the number of unintended pregnancies not only reduces the number of abortions but also lowers the number of maternal and infant deaths associated with the risks of childbirth. [ 1 ] [ 2 ] [ 3 ]


In addition to reducing the number of unintended pregnancies, family planning programs run by organizations like United States Agency for International Development (USAID), [ 4 ]  the United Nations Population Fund (UNFPA), [ 5 ]  and the Bill & Melinda Gates Foundation [ 6 ]  work to reduce high fertility in developing countries and increase overall health standards for women and children to order to negate the burdens unintended pregnancies, high fertility rate, and infant and maternal mortality have on countries in the global South. [ 3 ]


The start of family planning as a formal tool of international development traces it origins to May 13, 1968 when the International Conference on Human Rights issued what became known as the Proclamation of Teheran. [ 7 ]  The Teheran Proclamation stated that for parents, being able to choose how many children they want to have and to choose the spacing of those children is a basic human right. [ 8 ]  While the importance of family planning had been known to the women it affected the most, it was not until the 1968 conference that family planning was seen as the obligations of countries and governments around the world. [ 7 ]  Family planning was and still is seen as a tool to not only help lower overall global fertility rates but also aid increasing the economic and social development in many countries, particularly in developing nations by lowering health risks associated with pregnancy and childbirth to women and children. [ 3 ]  Unintended pregnancies and high fertility rates can affect everything from quality of life, nutrition standards, access to education and economic opportunities and even access to scarce resources such as food and water for women and children. Family planning programs seek to give women of child-bearing age an opportunity to make their own reproductive choices. [ 3 ]  In 2017, an estimated $1.27 billion was raised for family planning programs worldwide. [ 9 ]   Partnerships such as Family Planning 2020 (FP2020), an international coalition jointly operating by the Bill & Melinda Gates Foundation, the United Nations and the governments of the UK and the US, seek to increase the availability of contraceptives to women who would otherwise not have access to them. [ 10 ]


International family planning programs as a part of development plans can have many positive benefits for women and the communities they serve. The Guttmacher Institute noted in a recent study that investment in contraceptive and maternal healthcare programs can not only significantly decrease the number of unintended pregnancies worldwide but also unplanned births and induced and unsafe abortions. [ 2 ]  Other studies have similarly shown that family planning programs can reduce the maternal mortality rate associated with childbirth. The maternal death rate in developing countries is much higher than in developed countries. [ 3 ]  Additionally, family planning programs help reduce the risk of sexually transmitted infections (STIs) including HIV/AIDS. [ 1 ]  It is often argued that family planning empowers women to make choices about their bodies and their reproductive health. [ 11 ]


While many studies and organizations have pointed out the benefits that family planning programs provide for the women they serve, they are not without their criticisms. There have been several documented cases around the world where women have been coerced into family planning. Researcher  Kalpana Wilson  noted that financial incentives given to doctors and non-governmental organizations (NGOs) that sterilized women as part of family planning programs amounted to creating a quota system that was rife for abuse and encouraged forced sterilizations for monetary gain, especially in vulnerable and marginalized communities. [ 12 ]  In India, one doctor who had performed tens of thousands of laparoscopic tubectomies was charged with performing the surgical procedure in unsanitary and hazardous conditions that led to several injuries and several deaths. [ 12 ]  Instances of forced sterilization is not an isolated case confined to India. In Peru, over 2000 poor women belonging to rural, indigenous communities were coerced and forced to be sterilized between 1995 and 2000. [ 13 ]  Critics of the Peruvian program suggest the health care workers were incentivized to sterilize the women for cash bonuses of ten dollars per woman. [ 13 ]  Since the 1980s, charges of forced sterilizations and abortions have been associated with the Chinese government's family planning program as well. [ 14 ]


Jonathan Høegh von Leunbach  ['lɔjnbɑk] (16 December 1884 – 24 September 1955) [ 1 ]  was a  Danish  doctor.  During the  interwar period  he made a significant but controversial social effort to help women of limited means with  sex education ,  birth control  and  abortion . [ 2 ]


Jonathan Leunbach was the son of Jørgen Høegh Leunbach (1842-1903) and Cassandra Wilhelmine Hjardemaal (1845-1925). [ 3 ]  He took a master's degree in medicine in 1912 and worked as a general practitioner in Brønderslev in  Jylland  1915-1917. After some years of hospital employment in  Copenhagen , he established himself here in 1922 as a general practitioner. [ 4 ]


Being a  socialist , Leunbach was in favour of  Wilhelm Reich's  sexual political ideas. In the 1920s he was known to the public through his agitation for better sex education, safe and affordable contraception and better access to abortion, particularly for poor families with many children.  In 1924, together with writer  Thit Jensen  he initiated  Foreningen for seksuel Oplysning  (Organization for Sexual Awareness), which worked for women's right to use  birth control , in particular the  diaphragm .


Thit Jensen broke off her collaboration with Leunbach in 1928, as she did not support his work for induced abortion. [ 5 ]  Internationally, Leunbach was a respected name, being co-founder of  the  Verdensligaen for seksuel Reform  (World League for Sexual Reform) in Copenhagen in 1927, while in Denmark he was met with massive resistance from most political parties, medical and ecclesial communities as well as the women's rights organisation  Dansk Kvindesamfund .


In the early 1930s, Leunbach performed some 300 abortions, [ 4 ]   and he was charged twice with complicity in illegal abortion. He was acquitted in 1935, but the following year was sentenced to three months in prison, [ 6 ]  lost his civil rights for five years, including being barred from working as a doctor. He and some contemporaries regarded this as a political conviction. Leunbachs work helped launch a debate on abortion, which in 1937 brought the Danish parliament to pass Denmark's first abortion legislation, which reduced the penalty for induced abortion and gave better opportunities to let a woman have an abortion for health reasons.


In 1939, the private organisation  Mødrehjælpen  (Mothers' Help), which was created in 1924 to help pregnant women to have their child, regardless of whether they were married or single, was made part of the public Danish social system. [ 7 ]  As part of the  sexual liberation , induced abortion was made legal in Denmark in 1973, and much of what Leunbach originally fought for is now regarded as self-evident rights.


Leunbach died in a drowning accident in Italy and is buried in  Hellerup Cemetery .


Leunbach is mentioned in episode 10 of the Danish TV series  Matador , where in 1935 one of the leading ladies creates a commotion in the town by supporting his thoughts on abortion. [ 8 ] [ 7 ] [ 9 ]


Nancy Beaton Loudon   OBE   FRCPE    (née  Mann ; 28 February 1926 – 20 February 2009) [ 1 ]  was a Scottish  gynaecologist . She devoted her professional life to pioneering, and ensuring provision of  family planning  and  well woman  services. [ 2 ]  She was a fore-runner in the specialty of 'community gynaecology'.


Nancy Mann was born at  Killen  on 28 February 1926, the eldest daughter of Helen and Alec J. Mann. Her father was a prominent farmer on the  Black Isle , and a  county councillor . Loudon showed her academic potential early by becoming  Dux  of  Fortrose Academy  in her final year of school. She began her medical studies at the  Medical School of the University of Edinburgh  in 1944, during war-time, graduating in 1949. She was one of only a small number of students each year who obtained their medical degree 'with honours'. [ 1 ] [ 3 ]


After graduation she worked as a registrar specialising in  obstetrics and gynaecology  at  Simpson's maternity hospital , Edinburgh, under the supervision of Professor  Robert James Kellar . [ 1 ]  When she became engaged to marry fellow gynaecologist, John Loudon, Kellar declared that there was no place for a married woman in obstetrics and she was forced to resign her post. [ 2 ]  Two years later, John Loudon was to accept the registrar post under Professor Kellar that Loudon had been forced to resign. [ 1 ]


Loudon's return to medical practice was a weekly session in the  Edinburgh Mothers' Welfare clinic ,  a  family planning  clinic. This clinic, the first in Edinburgh, was run on a voluntary basis by two doctors,  Maeve Marwick  and  Alexandra Lothian . [ 1 ]


Initially, the clinic had spartan premises - an old shop, possessing a cold tap only, and with the waiting room furnished with wooden benches. However, in 1957 a bequest of £2,000 allowed the purchase of premises in Dean Terrace, a Georgian town house carefully chosen for its secluded location. [ 1 ]  The clinic remained there for over 50 years, until it moved to Chalmers Community Clinic in Lauriston Place, at that point becoming a combined family planning, well woman and sexual and reproductive health clinic.


Birth control 'need', and word-of-mouth, meant local women flocked to the newly established clinic in Dean Terrace, and it became a groundbreaking centre for the  new methods of contraception  that were becoming available. Loudon took over as Principal Medical Officer in 1972, and at that time the clinic was Branch 50 of the  Family Planning Association  (FPA). The clinic was later subsumed into  Lothian Health Board .


Loudon had a supportive team at the Dean Terrace clinic, and these were exciting times for family planning, the many battles notwithstanding. The clinic service expanded to offer  well-woman screening ,  vasectomy , sexual problems clinics and place of work screening in local factories. She was proud of establishing the Lothian Abortion Referral Service, which streamlined the management of women seeking  abortion , reducing unnecessary and distressing delays. [ 2 ]


She pursued academic medical interests, and held a lectureship in the Department of Obstetrics and Gynaecology at the  University of Edinburgh . She was involved in research on  contraception , in particular,  steroid hormones , and her research work led to over 70 scientific publications. In 1985 she wrote a textbook,  The Handbook of Family Planning , [ 4 ]  which has continued as a popular text for doctors working in the field - the fifth edition, edited by University of Edinburgh colleagues including  Professor Anna Glasier , was published shortly before she died.


She was chairperson of the UK National Association of Family Planning Doctors, and held many other national medical roles. She was not afraid to challenge the establishment when the needs of women were threatened. In her time, the medical specialty of Family Planning has become firmly established in the UK, now known as the  Faculty of Sexual and Reproductive Healthcare . [ citation needed ]


Loudon retired in 1988.


Following retirement, she was awarded the  William Y Darling Bequest  by  Edinburgh District Council  for Good Citizenship, by a unanimous committee vote. Subsequently, she was elected a fellow of the  Royal College of Physicians of Edinburgh , [ 3 ]  and her contribution to medicine was marked with an  OBE  in 1992. [ 1 ]


Loudon was supported throughout her professional life by her husband, John Loudon, retired consultant obstetrician and gynaecologist. She had two sons and by 2009 had six grandchildren. [ 1 ]  She died 20 February 2009.


The  National Health and Family Planning Commission of the People's Republic of China  ( NHFPC ) was a  cabinet-level executive department  under the  State Council  which is responsible for providing information, raising health awareness and education, family planning, ensuring the accessibility of health services, monitoring the quality of health services provided to citizens and visitors in the  mainland ,  population  and  family planning  in the  People's Republic of China . In March 2018, the ministry was dissolved and its functions were integrated into the new agency called the  National Health Commission . [ 1 ]


The Ministry is created from the former  Ministry of Health  and  National Population and Family Planning Commission . This was announced at the  2013 National People's Congress .


From 16 March 2013 to March 2018, the commission is headed by  Li Bin . [ citation needed ]


The commission reports directly to the State Council. Its functions include:
 [ 2 ]


The  National Population and Family Planning Commission  ( NPFPC ; 2003–2013), formerly the  National Family Planning Commission  ( NFPC ; 1981–2003), was a  cabinet-level executive department  under the  State Council , responsible for  population  and  family planning policy  in the  People's Republic of China . The commission was dissolved and superseded by the  National Health and Family Planning Commission  in March 2013, during the first session of the 12th National People's Congress.


The agency was managed by a minister and four vice ministers. [ 1 ]


Natural family planning  ( NFP ) comprises the  family planning  methods approved by the  Catholic Church  and some  Protestant denominations  for both achieving and postponing or avoiding pregnancy. [ 1 ] [ 2 ]  In accordance with the Church's teachings regarding  sexual behavior , NFP excludes the use of other methods of  birth control , which it refers to as "artificial contraception".


Periodic  abstinence , the crux of NFP, is deemed moral by the Church for avoiding or postponing  pregnancy  for just reasons. [ 3 ]  When used to avoid pregnancy, couples may engage in sexual intercourse during a woman's naturally occurring infertile times such as during portions of her  ovulatory cycle .  Various methods may be used to identify whether a woman is likely to be  fertile ; this information may be used in attempts to either avoid or achieve pregnancy.


Effectiveness can vary widely, depending on the method used, whether the users were trained properly, and how carefully the couple followed the protocol.  Pregnancy can result in up to 25% of the user population per year for users of the symptoms-based or calendar-based methods, depending on the method used and how carefully it was practised.


Natural family planning has shown very weak and contradictory results in pre-selecting the sex of a child, with the exception of a Nigerian study at odds with all other findings. Because of these remarkable results, an independent study needs to be repeated in other populations. [ 4 ] [ 5 ]


In ancient history, some Christian writers were against abstinence to prevent childbirth and some allowed it. Possibly the earliest Christian writing about periodic abstinence was by  Clement of Alexandria . He wrote, "Let the Educator (Christ) put us to shame with the word of Ezekiel: 'Put away your fornications' [Eze. 43:9]. Why, even unreasoning beasts know enough not to mate at certain times. To indulge in intercourse without intending children is to outrage nature, whom we should take as our instructor." [ 6 ]


In the year 388,  St. Augustine  wrote against the Manichaeans: "Is it not you who used to counsel us to observe as much as possible the time when a woman, after her purification, is most likely to conceive, and to abstain from cohabitation at that time...?" [ 7 ]   The  Manichaeans  (the group the early church father St. Augustine wrote of and considered to be heretics) believed that it was immoral to create any children, thus (by their belief system), trapping souls in mortal bodies. Augustine condemned them for their use of periodic abstinence during fertile periods: "From this it follows that you consider marriage is not to procreate children, but to satiate lust." [ 8 ] : 120   About the year 401, St. Augustine wrote "Of the Good of Marriage" in which he affirmed married couples have the option of having sex without either of them intending procreation: "For, whereas that natural use, when it pass beyond the compact of marriage, that is, beyond the necessity of begetting, is pardonable in the case of a wife, damnable in the case of an harlot; that which is against nature is execrable when done in the case of an harlot, but more execrable in the case of a wife." [ 9 ]


Saint  Thomas Aquinas  wrote in his  Summa Contra Gentiles : "Hence it is clear that every emission of the semen is contrary to the good of man, which takes place in a way whereby generation is impossible; and if this is done on purpose, it must be a sin. I mean a way in which generation is impossible in itself as is the case in every emission of the semen without the natural union of male and female: wherefore such sins are called 'sins against nature.' But if it is by accident that generation cannot follow from the emission of the semen, the act is not against nature on that account, nor is it sinful; the case of the woman being barren would be a case in point." [ 10 ]


Protestant Reformers  such as  Martin Luther  and  John Calvin  were opposed to unnatural birth control. [ 11 ]  Centuries later,  John Wesley , the leader of the  Methodist  movement said that unnatural birth control could destroy one's soul. [ 11 ]


If the Manichaeans had an accurate idea of the fertile portion of the menstrual cycle, such knowledge died with them. [ 12 ]   Documented attempts to prevent pregnancy by practicing periodic abstinence do not appear again until the mid-19th century, when various  calendar-based methods  were developed "by a few secular thinkers". [ 13 ]   The Roman Catholic Church's first recorded official approval of periodic abstinence from 1853, where a ruling of the Church's  Sacred Penitentiary  addressed the topic. Distributed to confessors, the ruling stated that couples who had, on their own, begun the practice of periodic abstinence—if they had "grave reasons"—were not  sinning  by doing so. [ 14 ]


In the Catholic Church, a grave/significant reason for using NFP can include social, economical, medical and other analogous reasons that may motivate a couple to practise it to postpone pregnancy. [ 15 ]  The Church holds that the motivations behind NFP should not be selfish or self-centered. [ 15 ]


In 1880, the Sacred Penitentiary reaffirmed the 1853 ruling and went slightly further. It suggested that, in cases where the couple was already practising artificial birth control and could not be dissuaded to cease attempting birth regulation, the confessor might morally  teach  them of periodic abstinence. [ 14 ]


In 1905,  Theodoor Hendrik van de Velde , a Dutch gynecologist, showed that women only ovulate once per menstrual cycle. [ 16 ]   In the 1920s Japanese gynecologist  Kyusaku Ogino  and Austrian Hermann Knaus independently made the discovery that ovulation occurs about fourteen days before the next menstrual period. [ 17 ]   Ogino used his discovery to develop a formula for use in aiding infertile women to time intercourse to achieve pregnancy.


In 1930, John Smulders, a Roman Catholic physician from the Netherlands, used Knaus and Ogino's discoveries to create the rhythm method. Smulders published his work with the Dutch Roman Catholic medical association, and this was the official rhythm method promoted over the next several decades. [ 17 ]  While maintaining procreation as the primary function of intercourse, the December 1930 encyclical  Casti connubii  by  Pope Pius XI  gave recognition to a secondary—unitive—purpose of sexual intercourse. This encyclical stated that there was no moral stain associated with having marital intercourse at times when "new life cannot be brought forth". This referred primarily to conditions such as current pregnancy and menopause. [ 18 ]  In 1932, a Catholic physician published a book titled  The Rhythm of Sterility and Fertility in Women  describing the method, [ 13 ]  and the 1930s also saw the first U.S. Rhythm Clinic (founded by  John Rock ) to teach the method to Catholic couples. [ 19 ]   It was during this decade that Rev. Wilhelm Hillebrand, a Catholic priest in Germany, developed a system for avoiding pregnancy based on  basal body temperature . [ 20 ]


A minority of Catholic theologians continued to doubt the morality of periodic abstinence. [ 14 ]  Some historians consider two speeches delivered by  Pope Pius XII  in 1951 [ 21 ]  to be the first unequivocal acceptance of periodic abstinence by the Catholic Church. [ 13 ]   The 1950s also saw another major advance in  fertility awareness  knowledge:  Dr. John Billings  discovered the relationship between  cervical mucus  and fertility while working for the Melbourne Catholic Family Welfare Bureau. Billings and several other physicians studied this sign for a number of years, and by the late 1960s had performed clinical trials and begun to set up teaching centers around the world. [ 22 ]


The Vatican II  Constitution on the Church in the Modern World  declared: "While not making the other purposes of matrimony of less account, the true practice of conjugal love, and the whole meaning of the family life which results from it, have this aim: that the couple be ready with stout hearts to cooperate with the love of the Creator and the Savior. Who through them will enlarge and enrich His own family day by day" (50). Beyond that the council of bishops was told to leave to the  Pontifical Commission on Birth Control  the task of advising Pope Paul VI on the issue. 64 of the 68 Commission members who voted recommended allowing other means of contraception, but Paul VI determined otherwise. [ 23 ]


Humanae Vitae , published in 1968 by  Pope Paul VI , addressed a pastoral directive to scientists: "It is supremely desirable... that medical science should by the study of natural rhythms succeed in determining a sufficiently secure basis for the chaste limitation of offspring."  This is interpreted as favoring the then-new, more reliable symptoms-based  fertility awareness  methods over the rhythm method.  Just a few years later, in 1971, the first organization to teach a symptothermal method, using both mucus and temperature observations, was started.  Now called  Couple to Couple League International , this organization was founded by John and Sheila Kippley, lay Catholics, along with Dr. Konald Prem. [ 20 ]   During the following decade, other now-large Catholic organizations were formed: Family of the Americas(1977), [ 24 ]  and the  Creighton Model  as part of the Pope Paul VI Institute (1985), [ 25 ]  both mucus-based systems of NFP.


Use of the term  natural family planning  to describe calendar-based methods is considered incorrect by the  United States Conference of Catholic Bishops , which considers such methods "inaccurate". [ 26 ]  Some organizations have considered calendar-based methods to be forms of NFP. [ 27 ] : 154    For example, in 1999 the Institute for Reproductive Health at  Georgetown University  developed the Standard Days Method (SDM), which is more effective than the rhythm method. [ 28 ]  SDM is promoted by Georgetown University as a form of natural family planning. [ 29 ] [ 30 ]


It is estimated that 2%–3% of the world's reproductive age population relies on periodic abstinence to avoid pregnancy. [ 31 ]  However, what portion of this population should be considered NFP users is unclear. Some Catholic sources consider couples that violate the religious restrictions associated with natural family planning to not be NFP users. [ 27 ] : 13  [ 32 ]


There is little data on the worldwide use of natural family planning. In Brazil, NFP is the third most popular family planning method. [ 33 ]   The "safe period" method of  fertility awareness  is the most common family planning method used in India, although condoms are used by some. [ 34 ]  Of all American women surveyed nationally in 2002, only 0.9% were using "periodic abstinence" (defined as "calendar rhythm" and "natural family planning") compared to 60.6% using other contraceptive methods. [ 35 ]  In Italy, where the vast majority of citizens claims to be Catholic, NFP methods are rarely taught. [ 36 ] [ better source needed ]


In 2002, Sam and Bethany Torode, then a  Protestant Christian  couple, published a book advocating NFP use. [ 37 ] [ 38 ]  Many NFP clinics and teaching organizations are associated with the Catholic Church, as well as  the Church of Jesus Christ of Latter-day Saints  (LDS Church) [ 39 ]  and some members of the  Muslim  faith. [ 40 ]


Some  fundamental Christians  espouse  Quiverfull  theology, eschewing all forms of birth control, including natural family planning. [ 41 ]


Some proponents of NFP differentiate it from other forms of birth control by labeling them artificial birth control. [ 42 ] [ 43 ]   Other NFP literature holds that  natural family planning  is distinct from  contraception . [ 44 ] [ 45 ] [ 46 ]  Proponents justify this classification system by saying that NFP has unique characteristics not shared by any other method of birth regulation except for abstinence. NFP is open to life, [ 43 ] [ 46 ]  it alters neither the  fertility  of the woman nor the  fecundity  of a particular sex act. [ 44 ] [ 45 ]  That NFP can be used to both avoid or achieve pregnancy. [ 47 ]


The Catholic Church has often said that it considers the use of contraception not to conform with God's will for Catholic marriage, in that it interrupts the procreative aspect of the sexual union, making it unnatural and counter to what God has outlined for married couples. [ 48 ]  Pope John Paul II said in  Love and Responsibility  that an integral aspect of the love between husband and wife is the openness to the real potential of becoming a parent, or becoming a parent of another, whenever the spouses give of themselves in the sexual embrace. [ 49 ]  Edward Sri makes an additional commentary on  Love and Responsibility  in  Men, Women, and the Mystery of Love , claiming the openness to life within marriage bolsters an emotional intimacy to supplement physical intimacy. [ 50 ]


These claims about how contraception can negatively impact fidelity within marriage are supported by a 2021 study in of more than 2,000 married women, some of whom practised NFP within their marriage and some who practised contraception. The study found that women who practised NFP were 58% less likely than their peers who used contraception to get divorced. "Although there are lower odds of divorce among NFP users, the reason might be due to their religiosity." [ 51 ]


There are three main types of NFP: the symptoms-based methods, the calendar-based methods, and the breastfeeding or  lactational amenorrhea method .  Symptoms-based methods rely on biological signs of fertility, while calendar-based methods estimate the likelihood of fertility based on the length of past menstrual cycles.


Clinical studies by the  Guttmacher Institute  found that periodic abstinence resulted in a 25.3 percent failure under typical conditions, though it did not differentiate between symptom-based and calendar-based methods. [ 52 ]


Some methods of NFP track biological signs of fertility.  When used outside of the Catholic concept of NFP, these methods are often referred to simply as  fertility awareness-based methods  rather than NFP. [ 53 ]  The three primary signs of a woman's fertility are her  basal body temperature  (BBT), her  cervical  mucus, and her cervical position. [ 54 ]  Computerized  fertility monitors , such as  Lady-Comp , may track basal body temperatures, hormonal levels in urine, changes in electrical resistance of a woman's saliva, or a mixture of these symptoms. [ 55 ]


From these symptoms, a woman can learn to assess her fertility without use of a computerized device. Some systems use only cervical mucus to determine fertility. Two well-known mucus-only methods are the  Billings ovulation method  and the  Creighton Model FertilityCare System . If two or more signs are tracked, the method is referred to as a symptothermal method. Two popular symptothermal systems are taught by the  Couple to Couple League  and the Fertility Awareness Method (FAM) with  Toni Weschler .  A study completed in Germany in 2007 found that the symptothermal method has a method effectiveness of 99.6%. [ 56 ]


A study by the World Health Organization involving 869 fertile women from Australia, India, Ireland, the Philippines, and El Salvador found that 93% could accurately interpret their body's signals regardless of education and culture. [ 57 ]


A symptohormonal method of NFP developed at Marquette University uses the ClearBlue Easy fertility monitor and cycle history to determine the fertile window. [ 58 ]  The monitor measures estrogen and LH to determine the peak day. This method is also applicable during postpartum, breastfeeding, and perimenopause, and requires less abstinence than other NFP methods. [ 59 ]  Some couples prefer this method because the monitor reading is objective and is not affected by sleep quality as BBT can be.


Calendar-based methods determine fertility based on a record of the length of previous menstrual cycles.  They include the Rhythm Method and the Standard Days Method. The Standard Days method was developed and proven by the researchers at the Institute for Reproductive Health of Georgetown University. CycleBeads, unaffiliated with religious teachings, is a visual tool based on the Standard Days method. According to the Institute of Reproductive Health, when used as birth control, CB has a 95% effectiveness rating. Computer programs are available to help track fertility on a calendar. [ 60 ]


The  lactational amenorrhea method  (LAM) is a method of avoiding pregnancy based on the natural  postpartum   infertility  that occurs when a woman is  amenorrheic  and fully  breastfeeding .  The rules of the method help a woman identify and possibly lengthen her infertile period.


Roderick Hindery reported that a number of Western Catholics have voiced significant disagreement with the Church's stance on contraception. [ 61 ]  In 1968, the  Canadian Conference of Catholic Bishops  issued what many interpreted as a dissenting document, the  Winnipeg Statement , in which the bishops recognized that a number of Canadian Catholics found it "either extremely difficult or even impossible to make their own all elements of this doctrine" (that of  Humanae vitae ). [ 62 ]  Additionally, in 1969, they reasserted the Catholic principle of  primacy of conscience , [ 62 ]  a principle that they said should be properly interpreted. They insisted that "a Catholic Christian is not free to form his conscience without consideration of the teaching of the  magisterium , in the particular instance exercised by the  Holy Father  in an encyclical letter." [ 63 ]   Catholics for a Free Choice  claimed in 1998 that 96% of U.S. Catholic women had used contraceptives at some point in their lives and that 72% of U.S. Catholics believed that one could be a good Catholic without obeying the Church's teaching on birth control. [ 64 ]  According to a nationwide poll of 2,242 U.S. adults surveyed online in September 2005 by  Harris Interactive  (they stated that the magnitude of errors cannot be estimated due to  sampling errors ,  non-response , etc.), 90% of U.S. Catholics supported the use of birth control/contraceptives. [ 65 ]  A survey conducted in 2015 by the  Pew Research Center  among 5,122 U.S. adults (including 1,016 self-identified Catholics) stated 76% of U.S. Catholics thought that the Church should allow Catholics to use birth control. [ 66 ]


In 2003, the  BBC 's  Panorama  claimed that Church officials have taught that HIV can pass through the membrane of the latex rubber from which condoms were made. It was considered not true according to the  World Health Organization , [ 67 ]  despite a 2000 report by the  National Institutes of Health  (NIH) stating that consistent use of latex condoms reduced the risk of HIV transmission by approximately 85% relative to risk when unprotected, [ 68 ]  not 100% safe.


In an interview on Dutch television in 2004, Belgian Cardinal  Godfried Danneels  argued that the use of condoms should be supported to prevent  AIDS  if sex with a person infected with HIV should take place, though it is to be avoided. According to Danneels, "the person must use a condom in order not to disobey the commandment condemning murder, in addition to breaking the commandment which forbids adultery. ... Protecting oneself against sickness or death is an act of prevention. Morally, it cannot be judged on the same level as when a condom is used to reduce the number of births." [ 69 ]  In 2009, Pope  Benedict XVI  asserted that handing out condoms is not the solution to combating AIDS and actually makes the problem worse. He proposed "spiritual and human awakening" and "friendship for those who suffer" as solutions. [ 70 ]


Artificial family planning proponent  Stephen D. Mumford  claimed that the primary motivation behind the Church's continued opposition to contraceptive use is the impossibility to make changes without spoiling papal authority with regards to  papal infallibility . [ 71 ]  Mumford gives as an example the citation made by dissident theologian August Bernhard Hasler of a minority report co-authored by  Pope John Paul II  prior to his papacy:


If it should be declared that contraception is not evil in itself, then we should have to concede frankly that the Holy Spirit had been on the side of the Protestant churches in 1930 (when the encyclical  Casti connubii  was promulgated), in 1951 (Pius XII's address to the midwives), and in 1958 (the address delivered before the Society of Hematologists in the year the pope died). It should likewise have to be admitted that for a half century the Spirit failed to protect Pius XI, Pius XII, and a large part of the Catholic hierarchy from a very serious error. This would mean that the leaders of the Church, acting with extreme imprudence, had condemned thousands of innocent human acts, forbidding, under pain of eternal damnation, a practice which would now be sanctioned. The fact can neither be denied nor ignored that these same acts would now be declared licit on the grounds of principles cited by the Protestants, which popes and bishops have either condemned or at least not approved. [ 72 ]


It is said that none of the instances cited falls under the domain of papal infallibility; the Pope is not considered infallible except in the rare, solemn occasions when he is speaking  ex cathedra . [ 73 ]  According to M. R. Gagnebet, though the encyclical  Humanae vitae  is considered by some to be a non-infallible document, "the doctrinal authority of the Pope and the Bishops is not limited to infallible teaching. The duty of obedience is not restricted to definitions of faith". [ 74 ]


Theological opposition has come from some denominations of Protestant Christianity. The  Reformed  theologian  John Piper 's  Desiring God  ministry states of NFP, "There is no reason to conclude that natural family planning is appropriate but that 'artificial' (non-abortive) means are not." [ 75 ]   Eastern Orthodox  couple Sam and Bethany Torode, former advocates of NFP-only, have redacted their position to include barrier methods and explain their current theology this way:


We also see honest congruity with the language of the body by saying "no" to conception with our bodies (via barrier methods or sensual massage) when our minds and hearts are also saying "no" to conception. We don't believe this angers God, nor that it leads to the slippery slope of relativism or divorce. We strongly disagree with the idea that this is a mortal sin.... It's a theological attack on women to always require that abstinence during the time of the wife's peak sexual desire (ovulation) for the entire duration of her fertile life, except for the handful of times when she conceives. [ 76 ]


Traditionalist Catholic  priest  Francis Ripley  criticizes the concept: [ 77 ]


The use of the term "Natural Family Planning" has come under sharp attack from traditional Catholic writers in recent years because it implies the right of the couple to "plan" their family; whereas the Catholic norm is to let God plan one's family and to accept the children when (and if) God gives them—as a blessing from Him on the marital union and on society. [ 77 ]


No-scalpel vasectomy  (also called  non-scalpel vasectomy ,  keyhole vasectomy  or  NSV ) is a type of  vasectomy  procedure in which a specifically designed ringed clamp and dissecting  hemostat  is used to puncture the  scrotum [ 1 ]  to access the  vas deferens . This is different from a conventional or incisional vasectomy where the scrotal opening is made with a  scalpel . The NSV approach offers several benefits, including lower risk for bleeding, bruising, infection, and pain. [ 1 ]  The NSV approach also has a shorter procedure time than the conventional scalpel incision technique. [ 1 ]  Both approaches to vasectomy are equally effective. Because of the inherent simplicity of the procedure it affords itself to be used in  public health  programs worldwide. This method is used in over 40 countries for  male sterilisation . [ 2 ]


No-scalpel vasectomy was developed and first performed in China by Dr. Li Shunqiang with the aim of reducing men's fear related to the incision and increasing vasectomy use in China. [ 3 ]  In 1985, a team created by  EngenderHealth  visited his centre to learn the technique. [ 3 ]  One of the team members, Dr. Phaitun Gojaseni, introduced the no-scalpel technique in Thailand upon his return, while another member of the team, Dr.  Marc Goldstein , introduced the technique to the United States at the  NewYork–Presbyterian Hospital . Over time, the technique gained popularity and it is now a preferred method of male sterilization in many countries. [ 3 ]


No-scalpel vasectomy was introduced in India in 1998. A team of Indian surgeons led by Dr RCM Kaza travelled to Chengdu, China, to learn the technique under the aegis of EngenderHealth and the  UN . They then introduced the procedure in India, under the  National Rural Health Mission . The  Government of India  then proceeded to introduce the procedure in every district of India as an alternative to  tubal ligation  offered to women. [ citation needed ]


World Vasectomy Day  is celebrated on 7 November in India. [ 4 ]


No-scalpel vasectomy is a day case ( outpatient ) procedure and the patient is fit to go home the same day. [ 5 ]


The eligibility criteria for the no-scalpel vasectomy and the conventional vasectomy procedure are the same, although may vary from clinic to clinic.


No-scalpel vasectomy is performed under  local anaesthesia . Usually  lidocaine  2 percent is infiltrated into the  vas deferens  and the puncture site on the scrotum. This makes the procedure pain free. Some patients may prefer to receive  regional anaesthesia . [ citation needed ]


The vas deferens is isolated by three-finger technique on both sides. The ideal entry point for the needle is midway between the top of the  testes  and the base of the  penis . Usually, 100 mg  lidocaine  (without  epinephrine ) is injected to create a wheal. The no-scalpel vasectomy uses two specific instruments designed by Dr. Li Shunqiang. One is a ringed clamp and the other is a dissecting forceps. The ringed clamp is used to isolate and encircle the vas. The dissecting forceps is used to puncture the scrotal skin, spread tissues, and pierce the vas deferens to deliver it outside the scrotum. The vas deferens is then occluded. [ 3 ]


The most commonly used methods to occlude the vas deferens include: [ 6 ]


The American Urological Association recommends occlusion by one of the following methods to achieve highest efficacy: [ 6 ]


No-scalpel vasectomy has less pain, bleeding and infection than conventional vasectomy. [ 1 ]  No-scalpel vasectomy can also be done in less time and the individual is able to return to sexual activity sooner than traditional vasectomy surgery. [ 1 ]  However,  sperm  may still be present for 10–20 ejaculations, and some doctors may schedule a follow-up visit to confirm the success of the procedure. Additionally, there is approximately a 1 in 2,000 chance of pregnancy following a vasectomy, as some sperm may be able to cross the severed vas deferens. [ 5 ]


Complications are rare and can include: [ 7 ]


An  only child  is a person with no  siblings ,  by birth  or  adoption .


Throughout history, only-children were relatively uncommon. From around the middle of the 20th century,  birth rates  and average family sizes fell sharply for a number of reasons, including perceived concerns about  human overpopulation  and more women having their first child later in life due to  birth control  and  women in the workforce . The proportion of families in the United States with only-children increased during the  Great Depression  but fell during the  Post–World War II baby boom . [ 1 ]  After the  Korean War  ended in 1953, the South Korean government suggested citizens each have one or two children to boost economic prosperity, which resulted in significantly reduced birth rates and a larger number of only-children in the country. [ 2 ] [ 3 ]


From 1980 to 2015, the  one-child policy  in the  People's Republic of China  restricted most parents to having only one child, although it was subject to local relaxations and individual circumstances (for instance, when twins were conceived). [ 4 ] [ 5 ] [ 6 ]


Families may have an only child for a variety of reasons, including: personal preference,  family planning , financial and emotional or physical health issues, desire to travel, stress in the family, educational advantages, late marriage, stability, focus, time constraints, fears over pregnancy, advanced age, illegitimate birth,  infertility ,  divorce , and death of a sibling or parent. The premature death of one parent also contributed to a small percentage of marriages producing just one child until around the mid-20th century, not to mention the then-rare occurrence of divorce.


Only-children are sometimes said to be more likely to develop precocious interests (from spending more time with adults) and to feel  lonely . [ 1 ]  Sometimes they compensate for the aloneness by developing a stronger relationship with themselves [ 7 ]  or developing an active fantasy life that includes  imaginary friends .


In Western countries, only-children can be the subject of a stereotype that equates them with "spoiled brats".  G. Stanley Hall  was one of the first commentators to give only-children a bad reputation when he referred to their situation as "a disease in itself". Even today, only-children are commonly stereotyped as "spoiled, selfish, and bratty". [ 8 ]  While many only-children receive a lot of attention and resources for their development, it is not clear that, as a class, they are overindulged or differ significantly from children with siblings. [ 9 ]  Susan Newman, a social psychologist at  Rutgers University  and the author of  Parenting an Only Child , says that this is a myth. "People articulate that only children are spoiled, they're aggressive, they're bossy, they're lonely, they're maladjusted", she said. "There have been hundreds and hundreds of research studies that show that only children are no different from their peers." [ 8 ]  However, differences have been found. Research involving teacher ratings of U.S. children's social and interpersonal skills [ 10 ] [ 11 ]  has scored only-children lower in self-control and interpersonal skills.  While a later study failed to find evidence that this continued through  middle  and  high school , [ 12 ] [ 13 ]  a further study showed that deficits persisted until at least the fifth grade. [ 14 ]  Overall, most findings do not support the negative view of only-children, though there are differences.  Only-children have proven through many studies that they are smarter, more autonomous, more well-behaved, and more mature than their peers. [ failed verification ] [ 15 ]


In China, perceived behavioral problems in only-children have been called the  Little Emperor Syndrome , [ 16 ]  and the lack of siblings has been blamed for a number of social ills such as materialism and crime. However, recent studies do not support these claims, and show no significant differences in personality between only-children and children in larger families. [ 17 ]  The  one-child policy , which ended in 2015, was speculated to be the underlying cause of forced  abortions ,  female infanticide , underreporting [ 18 ]  of female births, and has been suggested as a possible cause behind China's increasing number of crimes and  gender imbalance .


The popular media often posit that it is more difficult for only-children to cooperate in a conventional family environment, as they have no competitors for the attention of their parents and other relatives. It is suggested that confusion arises about the norms of ages and roles and that a similar effect exists in understanding during relationships with other peers and youth, all throughout life. [ 19 ]  Furthermore, it is believed that many feel that their parents place extra pressure and expectations on the only child, and that often, only-children are perfectionists. [ 20 ]  Only-children are noted to have a tendency to mature faster. [ 19 ]  Some psychologists believe in the “only child syndrome," though there is very little evidence to back it up. “Only child syndrome” is the idea that in adulthood, those who have had no siblings are more likely to have less developed social skills and antisocial tendencies that have carried on from childhood.


A 1987  quantitative review [ 21 ]  of 141 studies on 16 different personality traits failed to support the opinion, held by theorists including  Alfred Adler , that only-children are more likely to be maladjusted due to pampering. [ 22 ]  The study found no evidence of any greater prevalence of maladjustment in only-children. The only statistically significant difference discovered was that only-children possessed a higher achievement motivation, which Denise Polit and  Toni Falbo  attributed to their greater share of parental resources, expectations, and scrutiny exposing them to a greater degree of reward, and greater likelihood of punishment for falling short. A second analysis by the authors revealed that only-children, children with only one sibling, and first-borns in general score higher on tests of verbal ability than later-borns and children with multiple siblings. [ 23 ]


A large ( n= 8,689) study found no evidence for the idea that only children are more narcissistic than children with siblings. [ 24 ]


Toni Falbo & Denise Polit, in their research of only children, gathered 115 studies to address information and evidence for personality, intelligence, adaptability, and relationships with peers and their parents. According to their findings, only-children surpassed all others in each category except for children who were in similar circumstances to them, such as first borns. One of their biggest findings was that the parent-child relationship was positively stronger compared to those children with siblings. Due to this relationship being significantly present in an only child's life, it correlated to developmental outcomes, showing that only-children were not at a developmental disadvantage. [ 15 ]


According to the Resource Dilution Model, [ 25 ]  parental resources (e.g. time to read to the child) are important in development. Because these resources are finite, children with many siblings are thought to receive fewer resources.  However, the Confluence Model [ 26 ]  suggests there is an opposing effect from the benefits to the non-youngest children of tutoring younger siblings, though being tutored does not make up the reduced share of parental resources. This provides one explanation for the poorer performance on tests of ability of only-children compared to first-borns, commonly seen in the literature, [ 26 ] [ 27 ]  though explanations such as the increased and earlier likelihood of experiencing parental separation or loss for last-born and only children have also been suggested, as this may be the cause of their very status. [ 27 ]


In his book  Maybe One , [ 28 ]  the environmental campaigner  Bill McKibben  argues in favor of a voluntary one-child policy on the grounds of climate change and overpopulation. He reassures the reader with a narrative constructed from interviews with researchers and writers on only-children, combined with snippets from the research literature, that this would not be harmful to child development. He argues that most cultural stereotypes are false, that there are not many differences between only-children and other children, and where there are differences, they are favorable to the only child.


Most research on only-children has been  quantitative  and focused on the behavior of only-children and on how others, for example teachers, assess that behavior. Bernice Sorensen, in contrast, used  qualitative methods  in order to elicit meaning and to discover what only-children themselves understand, feel, or sense about their lives that are lived without siblings. Her research showed that during their life span, only children often become more aware of their only-child status and are very much affected by society's stereotype of the only-child, whether or not the stereotype is true or false. She argues in her book,  Only Child Experience and Adulthood , that growing up in a predominantly sibling society affects only-children and that their lack of sibling relationships can have an important effect on both the way they see themselves and others and how they interact with the world. [ 29 ]


The latest research by Cameron et al. (2011) controls for endogeneity associated with being only-children. Parents that choose to have only one child could differ systematically in their characteristics from parents who choose to have more than one child. The paper concludes that "those who grew up as only children as a consequence of the [one-child] policy [in China] are found to be less trusting, less trustworthy, less likely to take risks, and less competitive than if they had had siblings. They are also less optimistic, less conscientious, and more prone to neuroticism". [ 30 ]  Furthermore, according to Professor Cameron, it was found that "greater exposure to other children in childhood – for example, frequent interactions with cousins and/or attending childcare – was not a substitute for having siblings". [ 31 ]


In his book  Born to Rebel ,  Frank Sulloway  provides evidence that  birth order  influences the development of the " big five personality traits " (also known as the Five Factor Model). Sulloway suggests that firstborns and only-children are more conscientious, more socially dominant, less agreeable, and less open to new ideas compared to later-borns. [ 32 ]  However, his conclusions have been challenged by other researchers, [ 33 ]  who argue that birth order effects are weak and inconsistent. In one of the largest studies conducted on the effect of birth order on the Big Five, data from a national sample of 9,664 subjects found no association between birth order and scores on the  NEO PI-R  personality test. [ 34 ]  Similarly, a large study (n = 8,689) from 2020 did not find any evidence for the hypothesis that only children are more narcissistic than non-only children. [ 35 ]


Sex and Society  ( Danish :  Sex & Samfund ) is a  non-profit organization  in  Denmark  which is responsible for providing  sex education  in the country. [ 1 ]  Due to Denmark's  birthrate  being under the  replacement rate  since the 1970s, in recent years the organization's focus has shifted from providing information on  contraception  to encouraging people to have children. [ 2 ]


Sex selection  is the attempt to control the sex of the offspring to achieve a desired sex. It can be accomplished in several ways, both pre- and post-implantation of an  embryo , as well as at  childbirth . It has been marketed under the title  family balancing .


According to the  United Nations Population Fund , the reasons behind sex selection are due to three factors and provide an understanding for sex ratio imbalances as well as to project future trends. These factors are:


The  United Nations Population Fund  states that "Local fertility restrictions and spontaneous rapid fertility decline below replacement levels tend to compel parents who want both a son and a small family size to resort to sex selection." [ 1 ]


In many cultures, male offspring are desired in order to inherit property, carry on the family name and to provide support for parents in old age. [ citation needed ]


In countries such as  India ,  China ,  Indonesia  and  Nepal  sons have been favored over daughters. [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ]  According to a 2018  Gallup poll , American parents favor boys by a 36% to 28% margin. The results were similar to a survey in 1941, when Americans preferred a boy to a girl by a 38% to 24% margin. The overall preference was driven by men, of whom 43% preferred a son compared to 24% who preferred a daughter. Men's preference for sons was most pronounced among men aged 18 to 29. Women, on the other hand, showed no preference for either sex, with 31% stating that they preferred a girl and 30% responding that they favored a boy. [ 7 ]


A 2009 study at the  University of Ulster  found that having sisters, as compared to brothers, can enhance the quality of an adult's life. [ 8 ]


There is a preference of parents to have a son over a daughter in many countries. [ 9 ]  This can be observed through sex ratios of children in various countries. [ 9 ]  Although biologically the sex ratio of children is around 95 girls to every 100 boys, this number generally evens out due to the higher infant mortality rate of boy infants. [ 9 ]  Scholars argue that the expected birth sex ratio in a normal population is in the range of 103 to 107 males to females at birth. [ 10 ] [ 11 ]
However, in a number of countries of  South Asia ,  East Asia  and the  Caucasus , the sex ratio of children is severely distorted. [ 12 ]  The problem is particularly severe in  China  and  India . The preference for sons over daughters can be connected to a number of reasons. In these countries, it is argued that son preference is linked to factors including economics, religion, and culture. [ 9 ]  Having a son ensures that families are more economically secure by not having to provide dowry payments, but rather being on the receiving end of this practice. [ 9 ]  In China, the  one child policy  has contributed to the sex imbalance, while the  dowry system in India  is responsible for a strong son preference. Furthermore, in countries where there are discriminatory practices regarding women inheriting, owning, or controlling land by law, having a son ensures that the family will not have to worry about the legal aftermath if something were to happen to them. [ 13 ]  It can also be argued that parents in these countries are aware of the potential hardship their daughter would have to endure in her lifetime, and therefore prefer to have a son in order not to see their daughter endure such difficulties. Many times this son preference results in  female foeticide  and pre-natal sex selection. [ 14 ]


Two major types of pre-implantation methods can be used for social sex selection. Both of them are based on actively rendering the second  sex chromosome  to be either a  Y chromosome  (resulting in a  male ), or an  X chromosome  (resulting in a  female ). [ 15 ]


The  Ericsson method , first applied in a  clinical setting  in the 1970s by Dr. Ronald J. Ericsson, uses higher  concentrations  of sperm of the desired sex to increase the likelihood of  conceiving  that sex. [ citation needed ]


When used to increase the likelihood of a female child, studies have resulted in between 70% and 80% female children. [ 16 ] [ 17 ] [ 18 ]


When used to increase the likelihood of a male child, studies have resulted in between 50% [ 17 ]  and 75% male children. [ 18 ]


Currently, approximately 50 gender selection centers in the United States use the Ericsson Method for artificial gender selection. [ 19 ]


The Ericsson method separates male and female sperm by passing them through a column filled with  blood protein ,  human serum albumin . As the sperms enter the human serum albumin, the differences in  mass  between the X and Y chromosomes manifest as the lighter male sperms push deeper into the protein than the females dragged down by the  weight  of the extra "leg" of the X sex chromosome. [ 20 ]  This tiny difference creates separate layers of concentrated male and female sperm. The layers of gender-selected sperm are of higher concentrations but not pure. This lack of purity explains the 30% chance of gender selection failure of the Ericsson method. [ 21 ]


After  ovarian stimulation , multiple eggs are removed from the mother. The eggs are fertilized in the laboratory using the father's sperm in a technique called  in vitro fertilization  (IVF). " In vitro " is  Latin  for "within  glass ". Fertilized eggs are called  embryos . As the embryos develop through  mitosis , they are separated by sex. Embryos of the desired sex are implanted back in the mother's  uterus . [ citation needed ]


Prior to fertilization with IVF, the fertilized eggs can be genetically  biopsied  with  preimplantation genetic diagnosis  (PGD) to increase fertilization success. [ 22 ]  Once an embryo  grows  to a 6-8 cell size, a small laser incision in the egg membrane (zona pellucida) allows safe removal of one of the cells. [ 23 ]  Every cell in the embryo contains an identical copy of the  genome  of the entire person. Removal of one of these cells does not harm the developing embryo. [ 24 ]  A  Geneticist  then studies the chromosomes in the extracted cells for  genetic defects  and for a definite analysis of the embryo's sex. [ 25 ]  Embryos of the desired sex and with acceptable genetics are then placed back into the mother. [ citation needed ]


The IVF/PGD technique is favored over the Ericsson method because of the stricter control of the sex of the offspring in the laboratory. Since only embryos of the desired sex are transferred to the mother, IVF/PGD avoids the small likelihood present in the Ericsson method of an undesired sperm fertilizing the egg. Sex selection success rates for IVF/PGD are very high. The technique is recommended for couples who will not accept a child of the undesired sex. [ 26 ] [ 27 ]


Timing methods aim to affect the sex ratio of the resultant children by having  sexual intercourse  at specific times as related to  ovulation . Studies have not been consistent about whether timing methods have any influence on the sex of the baby, with some showing no correlation [ 28 ]  and others showing just the opposite. [ 29 ] [ 30 ]


Sperm sorting is an advanced technique that sorts sperm "in vitro" by  flow cytometry . This shines a  laser  at the sperm to distinguish X and Y chromosomes, and can automatically separate the sperm out into different samples. During the early to mid 1980s, Dr. Glenn Spaulding was the first to sort viable whole human and animal spermatozoa using a flow cytometer, and utilized the sorted motile rabbit sperm for artificial insemination. Subsequently, the first patent application disclosing the method to sort "two viable subpopulations enriched for x- or y- sperm" [ 33 ]  was filed in April 1987 as US Application Serial Number 35,986 and later became part of US Patent 5,021,244; and the patent included the discovery of  haploid  expression (sex-associated membrane proteins, or SAM proteins) and the development of monoclonal antibodies to those proteins. Additional applications and methods were added, including antibodies, from 1987 through 1997. [ 34 ]  At the time of the patent filing, both Lawrence Livermore National Laboratories and the USDA were only sorting fixed sperm nuclei, [ 35 ]  after the Application Serial Number 35,986 patent filing a new technique was utilized by the USDA where "sperm were briefly sonicated to remove tails". [ 36 ]  USDA in conjunction with Lawrence Livermore National Laboratories, 'Beltsfield Sperm Sexing Technology' relies on the DNA difference between the X- and Y- chromosomes. [ 37 ]  Prior to flow cytometric sorting, semen is labeled with a fluorescent dye called Hoechst 33342 which binds to the DNA of each spermatozoon. As the X chromosome is larger (i.e. has more DNA) than the Y chromosome, the "female" (X-chromosome bearing) spermatozoa will absorb a greater amount of dye than its male (Y-chromosome bearing) counterpart. As a consequence, when exposed to UV light during flow cytometry, X spermatozoa fluoresce brighter than Y- spermatozoa. As the spermatozoa pass through the flow cytometer in single file, each spermatozoon is encased by a single droplet of fluid and assigned an electric charge corresponding to its chromosome status (e.g. X-positive charge, Y-negative charge). The stream of X- and Y- droplets is then separated by means of electrostatic deflection and collected into separate collection tubes for subsequent processing. [ 38 ]  The technology is already in commercial use for animal farming. [ 39 ]  It is currently being trialed on humans in the US under the trademark MicroSort; it claims a 90% success rate but is still considered experimental by the  FDA . [ 40 ] [ 41 ]


Sex selection after implantation can be performed by  prenatal sex discernment , followed by  sex-selective abortion  of any offspring of the unwanted sex. For prenatal sex discernment, a  blood test  can be taken from the mother for testing of small amounts of fetal DNA within it, and has been estimated to be reliable more than 98% of the time, as long as the samples are taken after the seventh week of pregnancy. [ 42 ] [ 43 ]


Sex-selective infanticide  - Killing children of the unwanted sex. Though illegal in most parts of the world, it is still practiced. [ citation needed ]


Sex-selective  child abandonment  - Abandoning children of the unwanted sex. Though illegal in most parts of the world, it is still practiced. [ citation needed ]


Sex-selective  adoption  - Placing children of the unwanted sex up for adoption. Less commonly viewed as a method of social sex selection, adoption affords families that have a gender preference a legal means of choosing offspring of a particular sex. [ citation needed ]


The application of these techniques to humans creates moral and ethical concerns in the opinion of some, while the advantages of sensible use of selected technologies is favored by others. [ citation needed ]


In contrast, in an interview study, sex-selection technology providers generally argued that sex selection is an expression of  reproductive rights , was initiated and pursued by women, and was a sign of female empowerment that allowed couples to make well-informed family planning decisions, prevented occurrences of  unintended pregnancy  and  abortion , and minimized  intimate partner violence  and/or  child neglect . [ 44 ]  The Ethics Committee of the American Society of Reproductive Medicine concluded that it is ethically appropriate to employ these new reproductive technologies to avoid the birth of children with X-linked genetic disorders. [ 45 ]  However, to use preimplantation genetic diagnosis and sex selection solely for non-medical reasons, the committee claims, is morally inappropriate. [ 46 ]  Also,  primary care physicians  questioned whether women could truly express free choice under pressure from family and community. [ 44 ]  In addition, primary care physicians voiced the concerns that sex selection led to invasive medical interventions in the absence of therapeutic indications, contributed to  gender stereotypes  that could result in child neglect of the lesser-desired sex, and was not a solution to domestic violence. [ 44 ]


Post-conceptual selection by preimplantation testing (PGD) also involves preferential use of embryos, and termination of pregnancy for gender selection also raises many ethical questions of the  abortion debate . [ citation needed ]


In addition to the ethical concerns mentioned, issues of  demographics  arise in societies where social sex selection is common. A society may exhibit a widespread bias towards having children of a specific gender, either due to cultural biases or economic concerns (e.g. male children may be more employable in the future and thus provide more financial support). When combined with frequent social sex selection, this bias may produce a  gender imbalance  that has undesirable consequences. This phenomenon has been observed in many nations in the  Far East , such as  India  and  China , where social sex selection has produced unnaturally high male/female ratios in the population. Couples in these areas use reproductive technologies to choose the sex of their children, which ultimately leads to a skew the human sex ratio toward a disproportionately male population. [ 47 ]  Sex selection has also been detected in several countries of Eastern Europe such as  Albania  or  Azerbaijan . [ 48 ] [ 49 ]  A 2012 report by  UNFPA  estimates that the total gender gap due to prenatal and postnatal gender discrimination amounts to 117 million women. [ 50 ]  China's gender imbalance is further increased by the  One Child Policy , although applicable only in most urban populations. In these nations, a lack of opportunity for many men to marry is believed to be producing increases in  crime , demand for  prostitution , mass  emigration , and the selling of brides. [ 51 ] [ 52 ]


China's 'one child family' policy is considered largely responsible for the substantial imbalance of the sex ratio. [ 53 ]  Chinese government reports show that the  sex ratio  for newborns is 118:100 (boys: girls), higher in rural areas such as  Guangdong  and  Hainan  (130:100) compared to the average of 104:100 in developed countries. It is believed that the ratio would increase further to the point that, by 2020, men of marriageable age would be unable to find mates, resulting in large social problems. [ 52 ] [ 54 ]


Some nations, such as India, have attempted to curtail these gender imbalances with criminal statutes. In contrast, bioethicist  Jacob Appel  of  New York University  has argued that governments should pay couples to choose to have female children. According to Professor Appel, "if female babies [were] worth their weight in  rupees  and  yuan , economic and educational opportunities for girls would soon follow." [ citation needed ]


In contrast, actual experience in Western cultures provides no evidence for any degree of gender imbalance from technologies which have long been available and legal – such as selective abortion or preimplantation embryo testing. When used for family balancing indications in such countries as the United States, pre-conceptual sex selection is widely sought without any preferential selection of males. A 1993 survey of more than 2300 pregnant women in the British population found no overall preference for either sex. These findings are largely consistent with other surveys conducted in the US. [ 47 ]  Thus the right of individual families to determine whether or not to balance gender of offspring in their families is not and will not become, in many countries, a demographic issue. Furthermore, in countries where such demographic issues exist because of strong gender preferences in a segment of the population, regulatory and legal control of, without denial of access to, sperm sorting technology can be utilized to provide individuals with choices while ensuring that equal numbers of boys and girls are produced for population demographic equality. [ citation needed ]


Sex selection is not new. [ 55 ]  There are a wide variety of social sex selections methods which have not been demonstrated to be effective. Because even implausible and ineffective methods have a success rate of 50%, many continued to be recommended by word of mouth. [ citation needed ]


The Greeks and Romans did not have a consistent theory of how sex was determined. Pliny the Elder claims that tying the right testicle of a ram will cause him to produce only females, but does not claim this about other creatures. [ 56 ]   Pseudo-Plutarch  lists many Greek theories of sex determination, including heat and cold, left and right testicles, left and right sides of the body, sperm crossing or not crossing from one side of the womb to the other, and the strength or dominance of various body parts. [ 57 ]


An 18th-century French book called  The art of boys  suggested an extreme method of ensuring children of one sex. The author suggests that one testicle and one ovary are intended for each sex. By removing a testicle or ovary, children of the other sex can be guaranteed. [ 58 ]


Since the ancient China, Chinese people use Chinese Gender Chart to predict and select baby's gender. Chinese Gender Calendar was buried in an imperial mausoleum with a history of over 300 years. It was calculated and deduced by the ancient Chinese based on Yin-Yang, Five Elements, Eight Diagrams and time. [ 59 ]


This calendar is a simple chart who matches the day of conception of the future child with the age of the mother at the day of conception. This table contains one more chance to conceive a boy. This may reflect the current female / male ratio. [ 60 ]


Census data from India show an imbalance in sex ratios among children in the early 20th century, such disparities almost always reflect a preference for sons. [ 55 ]


In the past, son preference may have resulted in the neglect or killing of female infants. However, since the early 1980s, ultrasounds and other technologies have enabled parents to detect the sex of a foetus during prenatal screenings. Those who prefer sons may arrange to abort female foetuses. This has accelerated sex-ratio imbalances at birth in parts of the world. It is estimated that, over the past generation, tens of millions of female foetuses have been aborted. Since the 1990s, some areas have seen up to 25 per cent more male births than female births. [ 55 ]
Sperm sorting utilizes the technique of  flow cytometry  to analyze and 'sort'  spermatozoa . During the early to mid-1980s, Dr. Glenn Spaulding was the first to sort viable whole human and animal spermatozoa using a flow cytometer, and utilized the sorted motile rabbit sperm for artificial insemination. Subsequently, the first patent application disclosing the method to sort "two viable subpopulations enriched for x- or y- sperm" [ 33 ]  was filed in April 1987 as US Application Serial Number 35,986 and later became part of US Patent 5,021,244; and the patent included the discovery of  haploid  expression (sex-associated membrane proteins, or SAM proteins) and the development of monoclonal antibodies to those proteins. Additional applications and methods were added, including antibodies, from 1987 through 1997. [ 34 ]  At the time of the patent filing, both Lawrence Livermore National Laboratories and the USDA were only sorting fixed sperm nuclei, [ 35 ]  after the Application Serial Number 35,986 patent filing a new technique was utilized by the USDA where "sperm were briefly sonicated to remove tails". [ 36 ]  USDA in conjunction with Lawrence Livermore National Laboratories, 'Beltsfield Sperm Sexing Technology' relies on the DNA difference between the X- and Y- chromosomes. [ 37 ]  Prior to flow cytometric sorting, semen is labeled with a fluorescent dye called Hoechst 33342 which binds to the DNA of each spermatozoon. As the X chromosome is larger (i.e. has more DNA) than the Y chromosome, the "female" (X-chromosome bearing) spermatozoa will absorb a greater amount of dye than its male (Y-chromosome bearing) counterpart. As a consequence, when exposed to UV light during flow cytometry, X spermatozoa fluoresce brighter than Y- spermatozoa. As the spermatozoa pass through the flow cytometer in single file, each spermatozoon is encased by a single droplet of fluid and assigned an electric charge corresponding to its chromosome status (e.g. X-positive charge, Y-negative charge). The stream of X- and Y- droplets is then separated by means of electrostatic deflection and collected into separate collection tubes for subsequent processing. [ 38 ]  In 1994, the first British baby was born through gender selection Sophie-May Clark.


Recently, a study published in 2006 indicated that mothers with  toxoplasmosis  have a significantly higher  sex ratio  of boys to girls. This has been discussed in connection with the  manipulation hypothesis  of parasites. [ 61 ]
Another study found a link between sex and the diet of the mother, but this may be due to statistical chance, and has yet to be confirmed. [ 62 ]


Sex selection is illegal in most of the world. There is  fertility tourism  from the  United Kingdom , [ 63 ]   Australia [ 64 ]  and  Canada [ 65 ]  to the  United States  for sex selection, because  preimplantation genetic diagnosis  (PGD, a potential expansion of IVF), which can be used for sex selection, is prohibited in the UK, Australia and Canada, except when it is used to screen for genetic diseases, while the laws in the US are more relaxed in this subject. [ citation needed ]


Sex selection is illegal in  China , but the Chinese government admits that the practice is widespread, especially in rural areas of China and among lawless groups such as  ghettoized  migrant workers in cities. [ 52 ] [ 66 ]


Sex selection is illegal in  India . Prenatal determination of sex through  ultrasound  is also illegal in India. [ 65 ]  In 1994, the  Pre-Conception and Pre-Natal Diagnostic Techniques Act  banned prenatal sex determination, and was strengthened by an amendment in 2003. [ 67 ]  These laws were instituted to combat the prevalent practice of  sex-selective abortion . Every genetic counselling centre, genetic laboratory or genetic clinic engaged in counselling or conducting pre-natal diagnostics techniques, like  In vitro fertilisation  (IVF) with the potential of sex selection ( Preimplantation genetic diagnosis ) before and after conception comes under purview of the PCPNDT Act and are banned. [ 68 ] [ 69 ] [ 70 ]  However, these laws have generally failed to be effective in rural areas and, despite education efforts, sex-selective abortion continues to be practiced in certain small parts of India. [ citation needed ]


Society for Family Development  ( Polish :  Towarzystwo Rozwoju Rodziny (TRR) ) is a Polish  organization  founded in 1957, aiming to promote the  sex education  of young people, providing assistance and support to individuals and couples in crisis situations, as well as providing care in the field of  sexual health .