Q&A: Preimplantation Diagnosis and Sex Selection

Prepared by the Center for Genetics and Society
January 2002

Q: What is preimplantation diagnosis (PGD)?

A: PGD is a procedure where an individual cell is extracted from a 6-10 - cell embryo which has been fertilized in vitro, and tested. Some fertility centers offer PGD in combination with in vitro fertilization (IVF) to couples at risk of passing a severe, genetic disease onto their offspring as a means of avoiding doing so. Embryos created via IVF are tested for the genetic condition in question and selected out prior to implantation in the uterus.

Q: For which medical conditions is PGD applicable?

PGD can be used to screen for select medical conditions that are caused by a known chromosomal anomaly or single, genetic mutation. These include: Down's syndrome, Tay-Sachs disease, Cystic Fibrosis, Sickle Cell disease, Huntington's Chorea, and Cooley's Anemia. PGD is also used to select for sex to avoid passing on serious sex-linked diseases, such as hemophilia and Duchenne's muscular dystrophy.

Q: How long have fertility specialists been offering PGD?

A: PGD was developed in the mid-1980's (Damewood 2001) and was first used in humans in 1990.

Q: How many "PGD-babies" have been born, worldwide?

It has been estimated that some 700 babies have been born, worldwide to women who underwent IVF-PGD procedures (Malone 2001, citing the International Working Group on Preimplantation Genetics). PGD appears to be on a steep rise; 600 of those 700 babies were born in just the last three years (Sills et al., 1999). [For a point of reference, one million IVF babies have been born, worldwide].

Q: How many clinics offer PGD for these purposes, worldwide?

A: Only 50 (Malone 2001). Many centers have not offered PGD for any purpose because of the difficult ethical challenges it poses.

Q: Is preventing the birth of infants with debilitating heritable impairments an acceptable use of PGD?

A: This use of PGD is generally accepted in the United States, yet in need of greater public consideration. Opponents of this use of PGD include disability rights activists, who argue that PGD fosters attitudes that promote discrimination against the sick or disabled because they were not "selected against" at birth. There is also concern that PGD will be used to prevent implantation of embryos with less severe genetic anomalies, as more is learned about the composition of the human genome. The difficulty in drawing the line with this technology cannot be ignored, particularly given the absence of regulation and oversight of the fertility field.

Q: What about using PGD to rescue another child?

A: PGD has recently been used in a few cases to select a "sibling-saving" embryo, or one with tissues compatible to that of an already existing child suffering from a fatal disorder. Two cases reported by the New York Times last year involved families each with a child suffering from Fanconi anemia, a recessive inherited disorder that causes bone marrow failure (Belkin 2001). This use of PGD is very controversial. Some critics argue that it is immoral to use a child as a means to save another. Moreover, when the ethical problems associated with PGD are considered along with the full costs to the parents, the sick child, the rescuer and the researchers and clinicians, some claim that alternative therapies such as tissue transplants from non-sibling donors may be a worthier research endeavor (Lagay 2001).

Q: Have any fertility specialists offered PGD for sex selection?

A: There is at least one center in Australia that performs sex selection for non-medical reasons using IVF and PGD (Savulescu 1999). It has been reported that select fertility centers in the United States have offered PGD for the sole purposes of sex selection upon request (Sills et al., 2000). The Center for Human Reproduction, Norbert Gleicher's organization, implicitly advertises this use of PGD in the "Treatment Options" section of its website:

PGD also lends itself to non-medically indicated gender selection and is, in contrast to other available gender selection techniques, which are principally based on sperm sorting (X- vs Y-carrying sperm), virtually always accurate. http://www.centerforhumanreprod.com/treatment_assisted.html

Q: How does using PGD for sex selection differ from "sperm sorting"?

A: Sperm sorting is a pre-conceptive method of sex selection, where clinics sort the father's sperm into X- and Y-bearing sperm. This method is around 75% accurate.

Q: What does it mean to use PGD for sex selection for "gender variety"?

A: Sex selection for "gender variety" refers to selecting the sex of a child for balancing the sex ratio in a family. It implies that a couple already has one or more children of one sex and wishes to ensure that their next child is of the opposite sex.

Q: Why should we be concerned about fertility centers offering PGD for sex selection to couples desiring "gender variety"?

Use of PGD for sex selection represents a clear departure from preventive medicine and towards designer babies. PGD is one of a series of technologies that represent a trend towards an unprecedented level of control over the genetic make-up of our offspring. Using PGD to preselect embryos for sex is especially problematic, because it is a clear example of a non-medical application of this already controversial technology. Allowing PGD to be used for this nonmedical purpose would open the door to allowing parents to select embryos on the basis of other non-essential genetic traits.

Any form of sex selection is inherently sexist. Elective human embryo sex selection reinforces the devaluation of one sex in favor of another and would enable gender discrimination at the very earliest stage of development.

Promotion of sex selection techniques in developed countries condones such techniques in other parts of the world where such practices have lead to huge social dislocations. In places such as India and China, where there is strong cultural pressure to have male children, significant demographic imbalances have occurred. In 1990, it was reported that there were 100 million women "missing" in South and East Asia (Benagiano and Bianchi 1999). While low-tech sex selection practices of female infanticide and selective abortion are responsible for skewing sex ratios in these countries, high-tech sex selection techniques promoted and used in the U.S. and other parts of the developed world would only serve to condone sex selection practices elsewhere.

Psychological harm to sex-selected offspring. Advocates of sex selection base their arguments on parental needs rather than asking what is best for the child as a person. Parental determination of a child's sex could adversely influence a child's interpersonal development, socialization processes, and core identity.

Once one fertility clinic operator begins explicitly offering this service, others will be pressured to follow. Demand for sex selection is already surprisingly high, and would likely increase, were centers to begin outwardly marketing these technologies. According to bioethicist Jeffrey Kahn, "This is such a competitive part of medicine…All it takes is one to offer gender selection (for nonmedical needs) and they will all follow suit" (Malone 2001).

Private fertility clinics and individual fertility specialists should not be making decisions about potentially lucrative technologies that have profound consequences to the human future. One fertility specialist indicated that he could fund all of his research until the day he died if he honored all the requests he got for sex selection (Kolata 2001).

Inappropriate use of medical resources. IVF and PGD should be preserved for people with a medical need for these technologies. Devoting limited fertility resources to sex selection would be unfair to couples who need the help of a fertility clinic to have a child at all.

Q: Wouldn't limiting the use of PGD for sex selection to couples desiring "gender balancing" (as opposed to using it with first-borns) be sufficient to prevent discriminatory uses of this technology?

A: Some argue that sex selection for family balancing it is not sexist, since a family already has a child of one sex and merely wants a child of the other sex. There are two rebuttals to this point. First, any form of sex selection is sexist; choosing sex in a sexist society presupposes and reinforces gender stereotypes. Secondly, how could we be assured that fertility centers were limiting sex selection to requests for it for "gender variety," particularly in the absence of regulatory oversight?

Q: What about cases where a couple is undergoing IVF and PGD for medical purposes, and the patient requests that gender determination to be added to the "criteria" for embryo selection?

A: Or what about cases where a couple is undergoing IVF for medical reasons, but does not need PGD, and requests PGD solely for gender determination? These should be discouraged. Of course, without regulatory oversight, it would be nearly impossible to ensure that all requests for these services were denied. But if ASRM were to take a strong stand against using PGD for sex selection, fertility specialists would be less likely to entertain such requests.

Q: Have any countries banned sex selection?

A: Article 14 of the Council of Europe's 1997 Convention on Human Rights and Biomedicine (ETS No. 164) states that techniques may not be used to choose a future child's sex, except where serious hereditary sex-related disease is to be avoided. The Convention has been signed by thirty of the Council's forty-one member states and ratified by ten of those thirty. Canada is currently considering legislation that would ban sex selection for nonmedical purposes. Using PGD for sex selection for nonmedical purposes is prohibited by the HFEA, the United Kingdom's regulatory authority which authorizes clinics to provide IVF procedures.

Q: What is the ASRM's current policy on sex selection?

A: In 1999, the ASRM issued a report which concluded, "The initiation of IVF with PGD solely for sex selection holds even greater risk of unwarranted gender bias, social harm and the diversion of medical resources from genuine medical need. It therefore should be discouraged" (ASRM Ethics Committee 1999). In May 2001, the ASRM released a report which concluded that physicians should be free to offer preconceptive methods of sex selection, if found to be safe and effective, to couples desiring "gender variety" under specified conditions (ASRM Ethics Committee 2001).

Q: Why is the ASRM's position on this matter of significance?

A: In the absence of a regulatory body to govern reproductive technologies, U.S. fertility specialists look to the ASRM for ethical guidance. The ASRM has a special responsibility to be cautious with these and other reproductive technology matters, especially given the self-policing nature of the fertility industry.

Q: Who is John Robertson?

A: John Robertson is a co-chair of the Ethics Committee of the ASRM. He is also a professor at the University of Texas School of Law in Austin. He is the author of The Rights of the Critically Ill (1983) and Children of Choice: Freedom and the New Reproductive Technologies (Princeton Press, 1994).

Robertson supports human reproductive cloning and believes parents should be able to engage in the positive selection of genetic characteristics of their offspring as an extension of their right to procreate. One of his articles which discusses these views and is featured on the Human Cloning Foundation's website is: "Liberty, Identity and Human Cloning," Texas Law Review 76: 1371 (1998)
(See, http://www.humancloning.org/robertso.htm).

Q: Who is Norbert Gleicher?

A: Dr. Gleicher is the founder and chair of the board of directors of the Center for Human Reproduction (CHR), which has five fertility centers in the Chicago area and four others in Manhattan and Brooklyn. CHR was founded in 1981. Gleicher is also the medical director of CHR-NY. In addition, he is an Adjunct Professor or Obstetrics and Gynecology at the NYU School of Medicine.

In addition to pushing sex selection techniques, Gleicher has publicly defended human reproductive cloning as an option for people with fertility problems. Following is Gleicher's response to the question, "What do you think about [Richard] Seed's cloning ideas for humans? during an interview with CNN in 1998:
"First of all I don't think it's an idea developed by Seed. I think fertility specialists have for a very long time talked about the fact that cloning can give us yet another treatment option for some selected couples. And fertility specialists have thought a lot about how to do this, and as a consequence I think sooner or later some cloning will take place as part of organized infertility care." (Cable News Network 1998).

Q: How do you respond to Gleicher's argument that we shouldn't deny a couple a "more accurate" technology: "How can you say that a method that would be 100% reliable is not ethically acceptable"?

A: Determining the ethical acceptability of a reproductive technology should not be based on an assessment of its "accuracy." The full social and ethical implications of a technology must be considered. Gleicher ignores these. In addition, in claiming PGD to be "100% accurate" he is ignoring the fact that the success of this method is dependent on successful implantation of the selected embryo. Finally, the actual reliability of IVF-PGD sex selection must take into account the risks to women associated with IVF, including the potential adverse health impacts of hormone injections for ova retrieval.

Q: Isn't sex selection a natural extension of reproductive rights?

A: Rights are socially negotiated. A right to procreate does not imply a right to procreate by whatever means possible. In this case, the social costs associated with this technology outweigh potential benefits to individuals wishing to undergo IVF-PGD for sex selection.

References:

ASRM Ethics Committee. 1999. Sex selection and preimplantation genetic diagnosis. Fertility and Sterility 72 (4): 595-598.
ASRM Ethics Committee. 2001. Preconceptive gender selection for nonmedical reasons. Fertility and Sterility 75 (5): 861-864.
Belkin, L. 2001. The made-to-order savior: Producing a perfect baby sibling. NYT, 1 July.
Benagiano, G. and Bianchi, P. 1999. Sex preselection: an aid to couples or a threat to humanity? Human Reproduction 14: 868-870.
Damewood, Marian D. 2001. Ethical implications of a new application of preimplantation diagnosis. JAMA 285 (24): 3143.
Kolata, Gina. 2001. Fertility ethics authority approves sex selection. NYT, 28 September.
Lagay, Faith. 2001. Preimplantation genetic diagnosis. Virtual Mentor Vol., 3 No. 8 (August).
Malone, M.E. 2001. A very early checkup: Genetic screening of embryos helps ease parents' fears, but is it a step toward "designer babies?" Boston Globe, 11 December.
Savulescu, Julian. 1999. Sex selection: the case for. MJA 171: 373-375.
Sills, Scott E., Dan Goldschlag, Delphine P. Levy, Owen K. Davis and Zen Rosenwaks. 1999. Preimplantation genetic diagnosis: Considerations for use in elective human embryo sex selection. Journal of Assisted Reproduction and Genetics 16 (10).

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