View source for Sex selection

{{Short description|Artificial selection of the sex of offspring}}
{{About|the artificial selection of the sex of offspring|the evolutionary concept|sexual selection}}
'''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 [[UNFPA|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:

# A [[preference for sons]] which stems from household structures "in which girls and women have a marginal social, economic and symbolic position, and consequently [[patriarchy|enjoy fewer rights]]."<ref name="sex imbalances">{{cite web|title=Sex Imbalances at Birth|url=http://www.unfpa.org/sites/default/files/pub-pdf/Sex%20Imbalances%20at%20Birth.%20PDF%20UNFPA%20APRO%20publication%202012.pdf|publisher=[[United Nations Population Fund|UNFPA]]}}</ref> These household structures also focus on security in which sons are expected to provide support to their parents throughout their life;
# Technological growth of prenatal diagnosis which allows parents to know the sex of their unborn child; and
# Low fertility which increases the need for sex selection by reducing the probability of having a daughter in smaller families.

The [[UNFPA|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."<ref name="sex imbalances"/>

== Preference for sex of child ==
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|date=November 2023}}

In countries such as [[India]], [[China]], [[Indonesia]] and [[Nepal]] sons have been favored over daughters.<ref>{{Cite book |editor-first1= S. |editor-last2= Lahiri-Dutt |title= Doing gender, doing geography: emerging research in India |location= New Delhi |publisher= Routledge |year= 2011 |page= 212 |url=https://books.google.com/books?id=EB63--z4zK0C&pg=PT212 |isbn= 978-0-415-59802-6 |editor-last= Ryju}}</ref><ref name=weiner>{{Cite book |editor-first1= M. |editor-last2= Varshney |editor-first2= A. |editor-last3= Almond |editor-first3= G. A. |title= India and the politics of developing countries |location= Thousand Oaks, Calif. |publisher= SAGE Publications |year= 2004 |page= 187 |url= https://books.google.com/books?id=ls38Az4-J64C&pg=PA187 |isbn= 978-0-7619-3287-1 |editor-last= Weiner }}</ref><ref>{{Cite book |editor-last= Joseph |editor-first= W. A. |title= Politics in China: an introduction |location= Oxford |publisher= Oxford University Press |year= 2010 |page= 308 |url= https://books.google.com/books?id=kk80evDTZIYC&pg=PA308 |isbn= 978-0-19-533530-9 }}</ref><ref name=lai-wan>{{Cite journal |last1= Lai-wan |last2= Eric |first2= B. |last3= Celia Hoi-Yan |first1= C. C. |title= Attitudes to and practices regarding sex selection in China |journal= Prenatal Diagnosis |volume= 26 |issue= 7 |year= 2006 |pages= 610–613 |doi= 10.1002/pd.1477 |pmid= 16856223 |first3= Chan|s2cid= 222098473 }}</ref><ref>{{Cite web |url= https://www.unfpa.org/gender/docs/studies/nepal.pdf |title= Sex selection: pervasiveness and preparedness in Nepal |work= United Nations Population Fund |date= September 2007 |access-date= May 13, 2013}}</ref> According to a 2018 [[Gallup (company)#Gallup Poll|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.<ref>{{Cite web|url=https://news.gallup.com/poll/236513/slight-preference-having-boy-children-persists.aspx|title=Slight Preference for Having Boy Children Persists in U.S.|date=5 July 2018}}</ref>

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.<ref>{{cite news|url=https://news.bbc.co.uk/2/hi/health/7977454.stm|title=BBC NEWS - Health - Sisters 'make people happy'|website=news.bbc.co.uk|date=2009-04-02}}</ref>

=== Cultural son preference ===
{{main|Son preference in China}}
[[File:2012 Birth Sex Ratio World Map.jpg|thumb|300px|World map of birth sex ratios, 2012]]
[[File:Danshan Nongguang Village Bulletin board.jpg|thumb|left|200px|The [[one child policy]] in [[China]] has contributed to the imbalanced sex ratios. Image shows a community bulletin board in Nonguang Village, [[Sichuan province]], China, keeping track of the town's female population, listing recent births by name and noting that several thousand yuan of fines for unauthorized births remain unpaid from the previous year.]]
There is a preference of parents to have a son over a daughter in many countries.<ref name="Seager2009">{{cite book|last=Seager|first=Joni|title=The Penguin Atlas of Women in the World|year=2009|publisher=Penguin Group|location=New York, New York|page=42}}</ref> This can be observed through sex ratios of children in various countries.<ref name="Seager2009"/> 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.<ref name="Seager2009"/> 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.<ref name=unfpa2012>[http://www.unfpa.org/webdav/site/global/shared/documents/publications/2012/Report_SexRatios_2012.pdf Report of the International Workshop on Skewed Sex Ratios at Birth] United Nations FPA (2012)</ref><ref name=kseb>Kraemer, Sebastian. "The Fragile Male." British Medical Journal (2000): n. pag. British Medical Journal. Web. 20 Oct. 2013.</ref>
However, in a number of countries of [[South Asia]], [[East Asia]] and the [[Caucasus]], the sex ratio of children is severely distorted.<ref>{{Cite web | url=https://www.cia.gov/library/publications/the-world-factbook/fields/2018.html | archive-url=https://web.archive.org/web/20070613003045/https://www.cia.gov/library/publications/the-world-factbook/fields/2018.html | url-status=dead | archive-date=June 13, 2007 | title=The World Factbook—Central Intelligence Agency}}</ref> 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.<ref name="Seager2009"/> 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.<ref name="Seager2009"/> 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.<ref>{{cite book|last=Seager|first=Joni|title=The Penguin Atlas of Women in the World|year=2009|publisher=Penguin Group|location=New York, New York|page=87}}</ref> 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 in India|female foeticide]] and pre-natal sex selection.<ref>{{cite journal |last1=Das Gupta |first1=Monica |last2=Zhenghua |first2=Jiang |last3=Bohua |first3=Li |last4=Zhenming |first4=Xie |last5=Chung |first5=Woojin |last6=Hwa-Ok |first6=Bae |title=Why is Son preference so persistent in East and South Asia? a cross-country study of China, India and the Republic of Korea |journal=Journal of Development Studies |date=December 2003 |volume=40 |issue=2 |pages=153–187 |doi=10.1080/00220380412331293807 |hdl=10986/19191 |s2cid=17391227 |url=http://crossasia-repository.ub.uni-heidelberg.de/3778/1/East%20and%20South%20Asia%20Son%20Preference.pdf }}</ref>

==Methods==
===Pre-implantation===
Two major types of pre-implantation methods can be used for social sex selection. Both of them are based on actively rendering the second [[XY sex-determination system|sex chromosome]] to be either a [[Y chromosome]] (resulting in a [[male]]), or an [[X chromosome]] (resulting in a [[female]]).<ref name="dugdale2009">{{MedlinePlusEncyclopedia|002327|Chromosome}}</ref>

====The Ericsson method====
The [[Ericsson method]], first applied in a [[Clinic|clinical setting]] in the 1970s by Dr. Ronald J. Ericsson, uses higher [[concentration]]s of sperm of the desired sex to increase the likelihood of [[Human fertilization|conceiving]] that sex.{{citation needed|date=November 2023}}

When used to increase the likelihood of a female child, studies have resulted in between 70% and 80% female children.<ref name="Silverman2002">{{cite journal|last1=Silverman|first1=A.Y.|title=Female sex selection using clomiphene citrate and albumin separation of human sperm|journal=Human Reproduction|volume=17|issue=5|year=2002|pages=1254–1256|issn=1460-2350|doi=10.1093/humrep/17.5.1254|pmid=11980748|doi-access=free}}</ref><ref name="JaffeJewelewicz1991"/><ref name="BeerninkDmowski1993"/>

When used to increase the likelihood of a male child, studies have resulted in between 50%<ref name="JaffeJewelewicz1991">{{cite journal|last1=Jaffe|first1=Sharon B.|last2=Jewelewicz|first2=Raphael|last3=Wahl|first3=Eric|last4=Khatamee|first4=Masood A.|title=A controlled study for gender selection|journal=Fertility and Sterility|volume=56|issue=2|year=1991|pages=254–258|issn=0015-0282|doi=10.1016/S0015-0282(16)54481-1|pmid=2070855|doi-access=}}</ref> and 75% male children.<ref name="BeerninkDmowski1993">{{cite journal|last1=Beernink|first1=Ferdinand J.|last2=Dmowski|first2=W. Paul|last3=Ericsson|first3=Ronald J.|title=Sex preselection through albumin separation of sperm**Presented in part at the 44th Annual Meeting of The American Fertility Society, Atlanta, Georgia, October 8 to 13, 1988.|journal=Fertility and Sterility|volume=59|issue=2|year=1993|pages=382–386|issn=0015-0282|doi=10.1016/S0015-0282(16)55681-7|doi-access=free}}</ref>

Currently, approximately 50 gender selection centers in the United States use the Ericsson Method for artificial gender selection.<ref name="silverman2010a">{{cite web |last=Silverman, M.D., Ph.D. |first= Andrew Y. |title=Gender Selection Ericsson Method |url=http://www.gender-select.com/gender_selection/ericsson-method/ |archive-url=https://archive.today/20130124015332/http://www.gender-select.com/gender_selection/ericsson-method/ |url-status=usurped |archive-date=January 24, 2013 |access-date= February 13, 2011}}</ref>

The Ericsson method separates male and female sperm by passing them through a column filled with [[Constituents of human blood|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.<ref name="dmowski1979">{{cite journal |last1=Dmowski |first1=WP |last2=Gaynor |first2=L |last3=Rao |first3=R |last4=Lawrence |first4=M |last5=Scommegna |first5=A |title=Use of albumin gradients for X and Y sperm separation and clinical experience with male sex preselection |journal=Fertility and Sterility |volume=31 |issue=1 |pages=52–7 |year=1979 |pmid=283932 |doi=10.1016/S0015-0282(16)43760-X |doi-access=free }}</ref> 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.<ref name="chenguu1997">{{cite journal |last1=Chen |first1=M. |last2=Guu |first2=HF |last3=Ho |first3=ES |title=Efficiency of sex pre-selection of spermatozoa by albumin separation method evaluated by double-labelled fluorescence in-situ hybridization |journal=Human Reproduction |volume=12 |issue=9 |pages=1920–6 |year=1997 |pmid=9363707 |doi=10.1093/humrep/12.9.1920 |doi-access=free }}</ref>

====IVF/PGD technique====
[[File:Embryo, 8 cells.jpg|thumb|right|350px| An 6-celled [[embryo]] prior to IVF/PGD analysis]]
{{Further|IVF|Preimplantation genetic diagnosis}}

After [[Ovulation induction|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 [[IVF|in vitro fertilization]] (IVF). "[[In vitro]]" is [[Latin language|Latin]] for "within [[Test tube|glass]]". Fertilized eggs are called [[embryo]]s. 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|date=November 2023}}

Prior to fertilization with IVF, the fertilized eggs can be genetically [[Biopsy|biopsied]] with [[preimplantation genetic diagnosis]] (PGD) to increase fertilization success.<ref name="pehlivan2003">{{cite journal |last1=Pehlivan |first1=T |last2=Rubio |first2=C |last3=Rodrigo |first3=L |last4=Romero |first4=J |last5=Remohi |first5=J |last6=Simón |first6=C |last7=Pellicer |first7=A |title=Impact of preimplantation genetic diagnosis on IVF outcome in implantation failure patients |journal=Reproductive BioMedicine Online |volume=6 |issue=2 |pages=232–7 |year=2003 |pmid=12676006 |doi=10.1016/S1472-6483(10)61715-4 |doi-access=free }}</ref> Once an embryo [[Cell growth|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.<ref name="boada1998">{{cite journal |last1=Boada |first1=M. |last2=Carrera |first2=M. |last3=De La Iglesia |first3=C. |last4=Sandalinas |first4=M. |last5=Barri |first5=P. N. |last6=Veiga |first6=A. |title=Successful use of a laser for human embryo biopsy in preimplantation genetic diagnosis: report of two cases |journal=Journal of Assisted Reproduction and Genetics |volume=15 |issue=5 |pages=302–7 |year=1998 |pmid=9604764 |doi=10.1023/A:1022548612107 |pmc=3454754 }}</ref> 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.<ref>{{cite journal |last1=Liebaers |first1=I. |last2=Desmyttere |first2=S. |last3=Verpoest |first3=W. |last4=De Rycke |first4=M. |last5=Staessen |first5=C. |last6=Sermon |first6=K. |last7=Devroey |first7=P. |last8=Haentjens |first8=P. |last9=Bonduelle |first9=M. |title=Report on a consecutive series of 581 children born after blastomere biopsy for preimplantation genetic diagnosis |journal=Human Reproduction |volume=25 |issue=1 |pages=275–82 |year=2010 |pmid=19713301 |doi=10.1093/humrep/dep298 |doi-access= }}</ref> A [[Geneticist]] then studies the chromosomes in the extracted cells for [[Genetic disorder|genetic defects]] and for a definite analysis of the embryo's sex.<ref name="bredenoord2009">{{cite journal |last1=Bredenoord |first1=Annelien |last2=Dondorp |first2=Wybo |last3=Pennings |first3=Guido |last4=De Die-Smulders |first4=Christine |last5=Smeets |first5=Bert |last6=De Wert |first6=Guido |title=Preimplantation genetic diagnosis for mitochondrial DNA disorders: ethical guidance for clinical practice |journal=[[European Journal of Human Genetics]] |volume=17 |issue=12 |pages=1550–9 |year=2009 |pmid=19471315 |pmc=2987024 |doi=10.1038/ejhg.2009.88 }}</ref> Embryos of the desired sex and with acceptable genetics are then placed back into the mother.{{citation needed|date=November 2023}}

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.<ref name="kanavakis2002">{{cite journal |last1=Kanavakis |first1=E |last2=Traeger-Synodinos |first2=J |title=Preimplantation genetic diagnosis in clinical practice |journal=Journal of Medical Genetics |volume=39 |issue=1 |pages=6–11 |year=2002 |pmid=11826017 |pmc=1734958 |doi=10.1136/jmg.39.1.6 }}</ref><ref name="silverman2010b">{{cite web |last=Silverman |first= Andrew Y. |title=Determine baby gender with IVF/PGD |url=http://www.gender-select.com/gender_selection/determine-baby-gender-with-ivfpgd/ |archive-url=https://web.archive.org/web/20100630183729/http://www.gender-select.com/gender_selection/determine-baby-gender-with-ivfpgd/ |url-status=usurped |archive-date=June 30, 2010 |access-date= February 12, 2011}}</ref>

====Timing methods====
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<ref>{{cite journal |last1=Wilcox |first1=Allen J. |last2=Weinberg |first2=Clarice R.|author2-link=Clarice Weinberg |last3=Baird |first3=Donna D. |title=Timing of Sexual Intercourse in Relation to Ovulation—Effects on the Probability of Conception, Survival of the Pregnancy, and Sex of the Baby |journal=New England Journal of Medicine |volume=333 |issue=23 |pages=1517–21 |year=1995 |pmid=7477165 |doi=10.1056/NEJM199512073332301 |doi-access=free }}</ref> and others showing just the opposite.<ref>{{cite journal |last1=Harlap |first1=Susan |title=Gender of Infants Conceived on Different Days of the Menstrual Cycle |journal=New England Journal of Medicine |volume=300 |issue=26 |pages=1445–8 |year=1979 |pmid=449885 |doi=10.1056/NEJM197906283002601 }}</ref><ref>{{cite journal |last1=McSweeney |first1=L |title=Successful sex pre-selection using natural family planning. |journal=African Journal of Reproductive Health |date=March 2011 |volume=15 |issue=1 |pages=79–84 |pmid=21987941 }}</ref>
* The [[Shettles Method|Shettles method]], first formally theorized in the 1960s by [[Landrum B. Shettles]], proposes that sperm containing the X (female) chromosome are more [[Semen quality|resilient]] than sperm containing the Y (male) chromosome. The method advocates [[Sexual intercourse|intercourse]] two to four days prior to [[ovulation]]. By the time ovulation occurs, the [[cervix]] should contain a higher concentration of female sperm still capable of fertilization (with most of the male sperm already dead). Intercourse close to ovulation, on the other hand, should increase the chances of conceiving a boy since the concentration of Y sperm will be higher at the [[Menstrual cycle#Ovulation|height]] of the [[menstrual cycle]].<ref name="shettles1991">{{cite journal |last1=Gray |first1=RH |title=Natural family planning and sex selection: fact or fiction? |journal=American Journal of Obstetrics and Gynecology |volume=165 |issue=6 Pt 2 |pages=1982–4 |year=1991 |pmid=1836712 |doi=10.1016/S0002-9378(11)90558-4 |doi-access=free }}</ref>
* The Whelan method is an "[[Fertility awareness|intercourse timing]]" method that advocates the opposite of the Shettles method. The Whelan method suggests intercourse four to six days prior to ovulation to increase the likelihood of fertilization by male sperm.<ref name="whelan2006">{{cite book |first=L. |last=Shettles |author2=D.M. Rorvick |chapter=How Do They Compare? |editor=Martin J. Whittle and C. H. Rodeck |title=How to Choose the Sex of Your Baby: The Method Best Supported by Scientific Evidence |publisher=Random House |location=New York |year=2006 |page=[https://books.google.com/books?id=ExmLlSUCI_UC&pg=PA90] |isbn=978-0-7679-2610-2 }}</ref>

====Sperm sorting====
{{Main|Sperm sorting}}
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"<ref name="patft.uspto.gov">[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5021244.PN.&OS=PN/5021244&RS=PN/5021244 US Patent 5,021,244, column 9, Sorting Sperm]</ref> 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.<ref name="ReferenceA">US Patent 5,021,244; 5,346,990; 5,369,012; 5,439,362; 5,496,722; 5,648,468; 5,660,997; PCT/US1989/002069</ref> At the time of the patent filing, both Lawrence Livermore National Laboratories and the USDA were only sorting fixed sperm nuclei,<ref name=pmid3506896>{{cite journal |last1=Johnson |first1=L. A. |last2=Flook |first2=J. P. |last3=Look |first3=M. V. |last4=Pinkel |first4=D. |title=Flow sorting of X and Y chromosome-bearing spermatozoa into two populations |journal=Gamete Research |volume=16 |issue=1 |pages=1–9 |year=1987 |pmid=3506896 |doi=10.1002/mrd.1120160102 }}</ref> 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".<ref name=pmid3507347>{{cite journal |last1=Johnson |first1=L. A. |last2=Flook |first2=J. P. |last3=Look |first3=M. V. |title=Flow cytometry of X and Y chromosome-bearing sperm for DNA using an improved preparation method and staining with Hoechst 33342 |journal=Gamete Research |volume=17 |issue=3 |pages=203–12 |year=1987 |pmid=3507347 |doi=10.1002/mrd.1120170303 }}</ref> USDA in conjunction with Lawrence Livermore National Laboratories, 'Beltsfield Sperm Sexing Technology' relies on the DNA difference between the X- and Y- chromosomes.<ref name=pmid18343491>{{cite journal |last1=Garner |first1=D.L. |last2=Seidel |first2=G.E. |title=History of commercializing sexed semen for cattle |journal=Theriogenology |volume=69 |issue=7 |pages=886–95 |year=2008 |pmid=18343491 |doi=10.1016/j.theriogenology.2008.01.006 }}</ref> 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.<ref name="pmid12537000" /> The technology is already in commercial use for animal farming.<ref>ABC Landline, [http://www.abc.net.au/tv/programs/landline/old-site/content/2006/s1624149.htm Dairy farms use gender selection process], 2006.</ref> 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 [[Food and Drug Administration|FDA]].<ref name=Microsort>{{cite web |publisher=MicroSort, Inc. |title=MicroSort Information |url=http://www.microsort.net/ |access-date=February 13, 2011}}</ref><ref>{{cite journal |author=Mayor S |title=Specialists question effectiveness of sex selection technique |journal=BMJ |volume=323 |issue=7304 |pages=67 |date=July 2001 |pmid=11451774 |pmc=1120747 |doi=10.1136/bmj.323.7304.67 }}</ref>

===Post-implantation===
{{Further|Prenatal sex discernment|Sex-selective abortion}}
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.<ref>{{cite journal |last1=Devaney |first1=Stephanie A. |last2=Palomaki |first2=Glenn E. |last3=Scott |first3=Joan A. |last4=Bianchi |first4=Diana W. |title=Noninvasive Fetal Sex Determination Using Cell-Free Fetal DNA |journal=JAMA |volume=306 |issue=6 |pages=627–36 |year=2011 |pmid=21828326 |pmc=4526182 |doi=10.1001/jama.2011.1114 }}</ref><ref>{{cite news |url=https://www.bbc.co.uk/news/health-14457670 |date=10 August 2011 |title=Baby gender blood tests 'accurate' |first=Michelle |last=Roberts |newspaper=[[BBC News Online]]}}</ref>

===Post-birth===
[[Sex-selective infanticide]] - Killing children of the unwanted sex. Though illegal in most parts of the world, it is still practiced.{{citation needed|date=November 2023}}

Sex-selective [[child abandonment]] - Abandoning children of the unwanted sex. Though illegal in most parts of the world, it is still practiced.{{citation needed|date=November 2023}}

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|date=November 2023}}

==Ethical concerns==
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|date=November 2023}}

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 [[Domestic violence|intimate partner violence]] and/or [[child neglect]].<ref name=puri>{{cite journal |last1=Puri |first1=Sunita |last2=Nachtigall |first2=Robert D. |title=The ethics of sex selection: a comparison of the attitudes and experiences of primary care physicians and physician providers of clinical sex selection services |journal=Fertility and Sterility |volume=93 |issue=7 |pages=2107–14 |year=2010 |pmid=19342036 |doi=10.1016/j.fertnstert.2009.02.053 |doi-access=free }}</ref> 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.<ref>{{cite journal | year = 1999 | title = Sex selection and preimplantation genetic diagnosis | journal = Fertil. Steril. | volume = 72 | issue = 4| pages = 595–598 | doi = 10.1016/s0015-0282(99)00319-2 | doi-access = free }}</ref> However, to use preimplantation genetic diagnosis and sex selection solely for non-medical reasons, the committee claims, is morally inappropriate.<ref name=":12">{{Cite journal|date=2000-09-01|title=Sex selection and preimplantation diagnosis: A response to the Ethics Committee of the American Society of Reproductive Medicine|first1= Julian |last1=Savulescu|first2= Edgar |last2=Dahl|journal=Human Reproduction|language=en|volume=15|issue=9|pages=1879–1880|doi=10.1093/humrep/15.9.1879|pmid=10966977|issn=0268-1161|doi-access=free}}</ref> Also, [[primary care physician]]s questioned whether women could truly express free choice under pressure from family and community.<ref name=puri/> 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 stereotype]]s that could result in child neglect of the lesser-desired sex, and was not a solution to domestic violence.<ref name=puri/>

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|date=November 2023}}

==Demographic concerns==
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.<ref name=":22">{{Cite journal|last1=P|first1=Liu|last2=GA|first2=Rose|date=1996-11-01|title=Ethics of sex selection for family balancing. Sex selection: the right way forward. Debate.|url=http://www.popline.org/node/302898|journal=Human Reproduction|language=en|volume=11|issue=11|pages=2343–2346|doi=10.1093/oxfordjournals.humrep.a019110|pmid=8981106|doi-access=free}}</ref> Sex selection has also been detected in several countries of Eastern Europe such as [[Albania]] or [[Azerbaijan]].<ref>[https://www.unfpa.org/gender/docs/UNFPA_report_Albania2012.pdf SEX IMBALANCES AT BIRTH IN ALBANIA] (2012)</ref><ref>{{cite report |date=2 May 2013 |title=Sex Imbalances at Birth in Armenia: Demographic Evidence and Analysis |publisher=UNFPA |url=https://armenia.unfpa.org/en/publications/%E2%80%9Csex-imbalances-birth-armenia-demographic-evidence-and-analysis%E2%80%9D-report }}</ref> A 2012 report by [[UNFPA]] estimates that the total gender gap due to prenatal and postnatal gender discrimination amounts to 117 million women.<ref>[http://www.unfpa.org/public/home/publications/pid/12405 Sex Imbalances at Birth], United Nations Population Fund (2012)</ref> 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.<ref>[https://news.bbc.co.uk/1/hi/world/south_asia/2723513.stm India's lost girls], BBC Online, 4 Feb 2003.</ref><ref name="AP 12-Jan-2007 China facing major gender imbalance">{{cite news |agency=Associated Press |date=January 12, 2007 |title=China facing major gender imbalance |url=https://www.nbcnews.com/id/wbna16593301 |publisher=NBC News |access-date=August 24, 2015}}</ref>

China's 'one child family' policy is considered largely responsible for the substantial imbalance of the sex ratio.<ref>{{Cite journal|title=Ethics of sex selection for family balancing: Family balancing as a morally acceptable application of sex selection|first=Guido|last=Pennings|date=1996|journal=Human Reproduction|volume=11|issue=11|pages=2339–2342|doi=10.1093/oxfordjournals.humrep.a019109|pmid=8981105|doi-access=free}}</ref> 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.<ref name="AP 12-Jan-2007 China facing major gender imbalance"/><ref>{{cite news| url=https://news.bbc.co.uk/2/hi/asia-pacific/3601281.stm | work=BBC News | title=China fears bachelor future | date=April 5, 2004}}</ref>

Some nations, such as India, have attempted to curtail these gender imbalances with criminal statutes. In contrast, bioethicist [[Jacob M. Appel|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 [[Chinese yuan|yuan]], economic and educational opportunities for girls would soon follow."{{citation needed|date=October 2013}}

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.<ref name=":22"/> 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|date=August 2015}}

==History and folk beliefs==
Sex selection is not new.<ref name="unfpa.org prenatal sex selection">[http://www.unfpa.org/prenatal-sex-selection Gender-biased sex selection]. United Nations Population Fund</ref> 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|date=November 2023}}

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.<ref>Pliny the Elder, ''The Natural History'', Book XXX, Chapter 16.</ref> [[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.<ref>[[Pseudo-Plutarch]], ''Placita Philosophorum'', Book V, Chapter VII.</ref>

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.<ref>Michel Procope-Couteaux, ''L'art de faire des garçons'', 1770, p. 129.</ref>

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.<ref>{{cite web |url=https://www.chinesegenderprediction.com/calendar/ |website=chinesegenderprediction.com|title=Chinese Gender Calendar}}</ref>

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.<ref>{{cite web |url=https://www.baby-gender-predictor.com |website=www.baby-gender-predictor.com|title=Chinese Gender Calendar}}</ref>

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.<ref name="unfpa.org prenatal sex selection"/>

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.<ref name="unfpa.org prenatal sex selection"/>
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"<ref name="patft.uspto.gov" /> 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.<ref name="ReferenceA" /> At the time of the patent filing, both Lawrence Livermore National Laboratories and the USDA were only sorting fixed sperm nuclei,<ref name="pmid3506896" /> 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".<ref name="pmid3507347" /> USDA in conjunction with Lawrence Livermore National Laboratories, 'Beltsfield Sperm Sexing Technology' relies on the DNA difference between the X- and Y- chromosomes.<ref name="pmid18343491" /> 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.<ref name="pmid12537000">{{cite journal |last1=Seidel |first1=George E. |last2=Garner |first2=Duane L. |title=Current status of sexing mammalian spermatozoa |journal=Reproduction |volume=124 |issue=6 |pages=733–43 |year=2002 |pmid=12537000 |doi=10.1530/rep.0.1240733 |doi-access=free }}</ref> 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 [[human sex ratio|sex ratio]] of boys to girls. This has been discussed in connection with the [[manipulation hypothesis]] of parasites.<ref name="toxo">{{cite journal |last1=Kaňková |first1=Š. |last2=Šulc |first2=J. |last3=Nouzová |first3=K. |last4=Fajfrlík |first4=K. |last5=Frynta |first5=D. |last6=Flegr |first6=J. |title=Women infected with parasite Toxoplasma have more sons |journal=Naturwissenschaften |volume=94 |issue=2 |pages=122–7 |year=2007 |pmid=17028886 |doi=10.1007/s00114-006-0166-2 |bibcode=2007NW.....94..122K |s2cid=9610443 }}</ref>
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.<ref>{{cite journal |last1=Mathews |first1=F. |last2=Johnson |first2=P. J |last3=Neil |first3=A. |title=You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans |journal=Proceedings of the Royal Society B: Biological Sciences |volume=275 |issue=1643 |pages=1661–8 |pmid=18430648 |pmc=2602810 |doi=10.1098/rspb.2008.0105 |year=2008}}</ref>

==Legality==
Sex selection is illegal in most of the world. There is [[fertility tourism]] from the [[United Kingdom]],<ref name=times>[https://www.thetimes.com/world/us-world/article/us-clinic-offers-british-couples-the-chance-to-choose-the-sex-of-their-child-5rl3pjcrw8z US clinic offers British couples the chance to choose the sex of their child] From The Times. August 22, 2009</ref> [[Australia]]<ref name=Bozovic>{{Cite journal |last1= Bozovic |first1= N. |title= Australian Couple Spend $50k to Have a Baby Girl |journal= Gender Selection |issn= 2204-3888 |volume= 1 |issue= 1 |year= 2014 |url= http://gender-selection.com.au/index.php/component/content/article/19-portfolio/dec-2014-1-1/27-australian-couple-spend-50k-to-have-a-baby-girl?Itemid=0 |access-date= 5 January 2015 |url-status= dead |archive-url= https://web.archive.org/web/20150105133928/http://gender-selection.com.au/index.php/component/content/article/19-portfolio/dec-2014-1-1/27-australian-couple-spend-50k-to-have-a-baby-girl?Itemid=0 |archive-date= 5 January 2015 }}</ref> and [[Canada]]<ref name=LoC/> 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|date=November 2023}}

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.<ref name="AP 12-Jan-2007 China facing major gender imbalance"/><ref>[http://fsi.stanford.edu/news/gender_imbalance_in_china_20081027/ Gender imbalance in China] October 27, 2008 - Shorenstein APARC, AHPP, SCP News. By Shannon Davidson, Jennifer Bunnell and Fei Yan</ref>

Sex selection is illegal in [[India]]. Prenatal determination of sex through [[ultrasound]] is also illegal in India.<ref name=LoC>Krishan S. Nehra, Library of Congress. [https://www.loc.gov/law/help/sex-selection/canada.php Sex Selection & Abortion: Canada]</ref> In 1994, the [[Pre-Conception and Pre-Natal Diagnostic Techniques Act, 1994|Pre-Conception and Pre-Natal Diagnostic Techniques Act]] banned prenatal sex determination, and was strengthened by an amendment in 2003.<ref>{{Cite journal |title=Banning of fetal sex determination and changes in sex ratio in India|journal=The Lancet|volume=3|issue=9|pages=e523–e524|date=September 2015|doi=10.1016/s2214-109x(15)00053-4|pmid=26275327|last1=Ahankari|first1=Anand S.|last2=Myles|first2=Puja|last3=Tata|first3=Laila J.|last4=Fogarty|first4=Andrew W.|doi-access=free}}</ref> 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.<ref>{{cite web|url=https://www.livemint.com/Politics/zigYIOwLa7gjBJmzqHjTSJ/Health-ministry-receives-complaints-against-web-giants-for-s.html|title=Health ministry receives complaints against web giants for sex determination violations|date=2018-01-05}}</ref><ref>{{cite news|url=https://timesofindia.indiatimes.com/india/To-ensure-prized-baby-boy-Indians-flock-to-Bangkok/articleshow/7169495.cms|title=To ensure prized baby boy, Indians flock to Bangkok|website=[[The Times of India]]|date=27 December 2010 }}</ref><ref>{{cite news|url=https://timesofindia.indiatimes.com/city/chandigarh/Chandigarh-IVF-expert-helps-police-arrest-Delhi-resident-seeking-sex-selection/articleshow/52926505.cms|title=Chandigarh IVF expert helps police arrest Delhi resident seeking sex selection|website=[[The Times of India]]|date=26 June 2016 }}</ref> 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|date=August 2015}}

== See also ==
* [[Femicide]]
* [[Gendercide]]
* [[Misogyny]]
* [[Sexism]]
* [[Violence against women]]

==References==
{{Reflist|2}}

==External links==
* [https://web.archive.org/web/20120303145017/http://www.microsort.com/en/whatismicrosort.shtml What is MicroSort Sex Selection] (archived from [http://www.microsort.com/en/whatismicrosort.shtml the original] on 2012-03-03)
* [http://www.cicred.org/Eng/Publications/pdf/BOOK_singapore.pdf A collection of essays on sex selection in various Asian countries by Attané and Guilmoto]
* [http://www.unfpa.org/gender/case_studies.htm Five case studies and a video on sex selection in Asia by UNFPA]
* [http://www.unfpa.org/public/home/publications/pid/12405 The 2012 United Nations study of factors and consequences of prenatal sex selection in the world]
* [https://www.ined.fr/fichier/s_rubrique/25088/03_pope2_2015_guilmoto_183.244.en.pdf A state of art review on birth masculinization by C. Z. Guilmoto]

===Ethical debates===
* [https://web.archive.org/web/20071111224047/http://www.cnn.com/HEALTH/9809/09/baby.sex.ethics/ Gender selection for babies poses ethical dilemmas] (archived from [http://www.cnn.com/HEALTH/9809/09/baby.sex.ethics/ the original] on 2007-11-11)
* [http://www.phgfoundation.org/news/3312 On fetal blood testing]
* {{cite journal |last1=Eftekhaari |first1=Tasnim Eghbal |last2=Nejatizadeh |first2=Abdol Azim |last3=Rajaei |first3=Minoo |last4=Soleimanian |first4=Saeede |last5=Fallahi |first5=Soghra |last6=Ghaffarzadegan |first6=Rahman |last7=Mahmoudi |first7=Forough |title=Ethical considerations in sex selection |journal=Journal of Education and Health Promotion |date=19 May 2015 |volume=4 |pages=32 |doi=10.4103/2277-9531.157184 |pmid=26097846 |pmc=4456876 |doi-access=free}}
{{Assisted reproductive technology}}

{{DEFAULTSORT:Sex Selection}}
[[Category:Sex selection| ]]
[[Category:Family planning]]
[[Category:Infanticide]]
[[Category:Human sex ratio]]
[[Category:Gendercide]]