Sex Selection in the United States

Sex Selection in the United States

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SEX SELECTION IN THE UNITED STATES

Tarun Jain MD, FACOG

Chicago IVF

The idea of couples being able to choose the sex of their child prior to conception is not new. From centuries past, many ‘methods’ have been proposed to give desiring couples the opportunity to choose a boy or girl. Effective medical options became available in the 1970s with the advent of ultrasound, amniocentesis, and chorionic villus sampling. With these options, however, an abortion would be necessary if a particular fetal sex was not desired. More recent scientific advancements, however, have made it possible for women to attempt sex selection prior to embryo creation or implantation. Although such technologies were initially intended to prevent the birth of children with sex-linked genetic disorders, they are being increasingly used for preimplantation sex selection for non-medical reasons.

The concept and use of sex selection for non-medical reasons is certainly not without significant ethical issues. The main concern is that widespread use of such technology may support sexist practices, alter the natural sex ratio, and lead to a socially disruptive imbalance of the sexes. This article will review the myths and technology currently available to patients, along with the potential ethical issues.

MYTHS

There is no shortage of old wives tales with regard to sex selection. The proposed methods have likely been tried by many patients around the world. Some of these methods are noted in Table 1. It is important to note, however, that most of these methods have not been scientifically tested and are likely no better than chance alone. The ‘timing of intercourse’ theory was rigorously studied with the conclusion that it had no influence on the sex of the resulting baby.1

TECHNOLOGY

The two methods currently available for preimplantation sex selection are sperm sorting and preimplantation genetic diagnosis (PGD) (Table 2).

Sperm sorting technology was originally developed by the United States Department of Agriculture for the purposes of selecting sex in livestock. Based on the birth of several hundred healthy offspring from four animal species, this technology was approved for clinical study in humans.2 It has subsequently been commercially available in the United States since 1995 as part of a Food and Drug Administration (FDA) sponsored clinical trial, with over 100 participating fertility clinics in 30 states.3-5 Couples who wish to use sperm sorting must also undergo intrauterine insemination (IUI) or in vitro fertilization (IVF) treatment. As of January 2007, over 900 live-births have been reported with use of this technology. Among couples opting for a girl, 92% of the babies have been female, and for those opting for a boy, 81% have been male.5 The technology is in its final phases of receiving FDA approval.

Use of PGD for non-medical sex selection may be appealing due to it’s nearly 100% accuracy for selecting the desired sex.6-8 Its use however, requires that couples undergo IVF treatment which has a significant added cost. Although the technology is widely available via most fertility clinics in the United States, it is not known how frequently it is used for non-medical sex selection.

Since 2001, the European Society of Human Reproduction and Embryology (ESHRE) has been publishing annual data on use of PGD for social sex selection among participating European fertility centers. In the most recent report of 39 fertility centers, a total of 85 IVF cycles that reached the oocyte retrieval stage were done for social sex selection.9 From these 85 cycles, 1071 oocytes were collected, 673 oocytes were fertilized, 469 embryos were biopsied (463 successfully), 390 embryos gave a diagnostic result, of which 154 (39%) were transferable (of the desired sex). Clinical pregnancy and live-birth rates per oocyte retrieval were 21% and 15%, respectively.

ETHICS

Use of preimplantation sex selection for non-medical reasons is one of the most controversial topics in bioethics today. Besides concern over creating societal gender imbalances if there is greater preference for one sex, there is concern over sex selection being driven by value differences ascribed to either sex, or that arise from gender stereotypes (gender discrimination).10-13 Others have suggested, however that such gender discrimination toward women is unlikely to occur in Western or developed societies.14,15

The American College of bstetricians and Gynecologists (ACOG) and the International Federation of Gynecology and Obstetrics (FIGO) already state their opposition to sex selection for non-medical reasons.16,17 After a two-year analysis, the President’s Council on Bioethics detailed its concerns on this technology, and continues to list sex selection under its ‘Topics of Council Concern.’18,19 The United Kingdom recently banned any technique used for non-medical sex selection, after public opinion surveys found the majority of respondents not in favor of such technology.20

In contrast, the Ethics Committee of the American Society for Reproductive Medicine (ASRM) in 2001 stated that preconception sex selection for non-medical reasons was ethically acceptable for the purpose of providing a family with a child of a different sex than an existing child (gender variety), provided the sex selection methods were safe and effective.21 In 2002, they clarified their position, stating that any non-medical use of PGD should be discouraged (although sperm sorting may still be acceptable).22

Opinion polling in the United States shows that only a small proportion (8%) of the general population would be interested in using such technology to select the sex of their next child.23 Among infertility patients, however, studies suggest that a significant proportion (41-49%) would be interested in use of such technology, with a significant demand coming from women who do not have any children.24,25 This is not surprising since infertile couples are more familiar and comfortable with such technologies since they often undergo IUI and/or IVF, which are necessary components of using sperm sorting or PGD. With regard to preferences of a particular sex, studies suggest a greater overall preference among infertility patients for girls (61-64%) than for boys (36-39%).24,25

SUMMARY

Preconception sex selection technology for non-medical reasons is commercially available in the United States, via sperm sorting or PGD. Sperm sorting is in the final stages of obtaining FDA approval. The availability and use of such technology has generated significant interest and controversy among medical societies, bioethicists, healthcare providers, and the government. Individual patients and providers should be aware of the technology along with the ethical issues.

REFERENCES

  1. Wilcox AJ, Weinberg CR, Baird DD. Timing of sexual intercourse in relation to ovulation. Effects on the probability of conception, survival of the pregnancy, and sex of the baby. N Engl J Med 1995;333:1517-21.
  2. Johnson LA, Welch GR, Keyvanfar K, Dorfmann A, Fugger EF, Schulman JD. Gender preselection in humans? Flow cytometric separation of X and Y spermatozoa for the prevention of X-linked diseases. Hum Reprod 1993;8:1733-9.
  3. Vidal F, Fugger EF, Blanco J, Keyvanfar K, Catala V, Norton M, et al. Efficiency of MicroSort flow cytometry for producting sperm populationsenriched in X- or Y-chromosome haplotypes: a blind trial assessed by double and triple colour fluorescent in-situ hybridization. Hum Reprod 1998;13:308-12.
  4. Fugger EF, Black SH, Keyvanfar K, Schulman JD. Births of normal daughters after microsort sprm separation and intrauterine insemination, in-vitro fertilization, or intracytoplasmic sperm injection. Hum Reprod 1998;13:2367-70.
  5. (accessed September 22, 2008).
  6. Handyside AH, Pattinson JK, Penketh RJ, Delhanty JD, Winston RM, Tuddenham EG. Biopsy of human preimplantation embryos and sexing by DNA amplification. Lancet 1989;1:347-349.
  7. Handyside AH, Kontogianni EH, Hardy K, Winston RM. Pregnancies from biopsied human preimplantation embryos sexed by Y-specific DNA amplification. Nature 1990; 344:768-70.
  8. Soussis I, Harper JC, Handyside AH, Winston RM. Obstetric outcome of pregnancies resulting from embryos biopsied for pre-implantation diagnosis of inherited disease. Br J Obstet Gynaecol 1996; 103:784-8.
  9. Goossens V, Harton G, Moutou C, Scriven PN, Traeger-Synodinos J, Sermon K, Harper JC. ESHRE PGD Consortium data collection VIII: cycles from January to December 2005 with pregnancy follow-up to October 2006. Hum Reprod 2008 Jul 18 [Epub ahead of print].
  10. Sen A. More than 100 million women are missing. New York Review of Books 1990;37:61-68.
  11. Allahbadia GN. The 50 million missing women. J Assist Reprod Genet 2002;19:411-6.
  12. Robertson JA. Preconception gender selection. Am J Bioeth 2001;1:2-9.
  13. Robertson JA. Extending preimplantation genetic diagnosis: the ethical debate. Ethical issues in new uses of preimplantation genetic diagnosis. Hum Reprod 2003;18:465-71.
  14. Simpson JL, Carson SA. The reproductive option of sex selection. Hum Reprod 1999;14:870-72.
  15. Savulescu J, Dahl E. Sex selection and preimplantation diagnosis. A response to the Ethics Committee of the American Society of Reproductive Medicine. Hum Reprod 2000;15:1879-80.
  16. American College of Obstetrics and Gynecology Committee on Ethics. ACOG Committee Opinion No. 360: Sex Selection. Obstet Gynecol 2007;109:475-8.
  17. FIGO Committee for the Ethical Aspects of Human Reproduction and Women’s Health. Ethical guidelines on sex selection for non-medical purposes. Int J Gynecol Obstet 2006;92:329-30.
  18. The President’s Council on Bioethics. Beyond therapy – Biotechnology and the pursuit of happiness. Washington, D.C., October 2003.
  19. The President’s Council on Bioethics. Reproduction and responsibility: The regulation of new biotechnologies. Washington, D.C., March 2004.
  20. Human Fertilisation and Embryology Authority. Sex selection: options for regulation. London: HFEA, 2003.
  21. Ethics Committee of the American Society for Reproductive Medicine. Preconception gender selection for nonmedical reasons. Fertil Steril 2001;75:861-4.
  22. Robertson JA. Sex selection for gender variety by preimplantation genetic diagnosis. Fertil Steril 2002;78:463.
  23. Dahl E, Gupta RS, Beutel M, Stoebel-Richter Y, Brosig B, Tinneberg HR, Jain T. Preconception sex selection demand and preferences in the United States. Fertil Steril 2006;85:468-73.
  24. Jain T, Missmer SA, Gupta RS, Hornstein MD. Pre-implantation sex selection demand and preferences in an infertility population. Fertil Steril 2005;83:649-58.
  25. Jain T, Missmer SA. Preimplantation sex selection demand and preferences among infertility patients in Midwestern United States. J Assist Reprod Genet 2007;24:451-7.

Table 1: Sex selection myths

1. 18th century France theory: Each testicle contains gender-specific sperm(girl sperm on left & boy sperm on right). Men who wanted a boy were encouraged to tie off their left testicle during intercourse.

2. Orgasm theory: Female orgasm during sex will produce a boy since the vaginal pH after an orgasm will favor male sperm.

3. Daylight theory: Girls are more likely to be conceived in the afternoon, while boys more likely at night.

4. Diet theory: To have a boy, women advised to eat red meat and salty snacks. To have a girl, women should eat fish, chocolate, and sweet products.

4. Sexual position theory: Various sexual positions will increase the chance of a boy or girl. This theory is based on beliefs that male sperm are small and fragile but quick, whereas female sperm are larger and tougher but slow.

5. Timing of intercourse theory (Shettles Method): Proposed by Dr. Landrum Shettles, based on theory that male sperm swim faster than female sperm. This theory recommends that if a male is desired, have intercourse close to the time of ovulation, since male sperm would get to the oocyte faster than female sperm.

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Table 2: Preimplantation sex selection technology

PROCEDUREDESCRIPTIONACCURACYCOST*

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Sperm sortingUses a flow cytometer to separate the 2.8% heavier 88% purity for X-bearing sperm$3700-

X- from Y-bearing sperm to produce X- and73% purity for Y-bearing sperm$4000

Y-enriched sperm samples for use with intrauterine

Insemination (IUI) or in vitro fertilization (IVF)

Preimplantation geneticRequires IVF treatment to create embryos, followed near 100%$2500-

diagnosis (PGD)by the removal of one or two blastomeres from embryos$3500

that contain 6-8 cells (2-3 days after fertilization). The

sex of the blastomere (and thus embryo) can then be

determined via DNA amplification or fluorescent in situ

hybridization (FISH) techniques.

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*Cost of IUI or IVF not included.

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