Family dynamics are changing. More women are choosing to delay having children. Additionally, there is a trend toward having smaller families. There are also more people starting a second or a third family with a new partner. These are only a few of the situations that contribute to reasons that couples seek out pre-implantation sex selection as part of their fertility planning. So what are the practical issues that should be considered about the ethics and practicality of using today’s technology?
Some centers differentiate between couples that want to choose the gender of their child for medical reasons vs. those that wish to do so for social (or personal) reasons. Like most providers that offer patients this right to choose, I view my role to respect and not question my patient’s decision regarding their reproductive rights. Instead, I view this as an extension of my responsibility to honor a woman’s right to choose contraception or her right to overcome infertility. The Ethics Committee [G1] of the American Society for Reproductive Medicine is likeminded. Their view is that in the absence of harm caused by gender selection; it is not justified to restrict the availability of this technology. It has been almost a decade since they posted this opinion and still no harm has been demonstrated. So what do we know about gender selection?
One large internet based survey [G2] found that about 8% of women and men between 18 and 45 years of age would use pre-conception sex selection. In a separate study [G3] which focused on women undergoing fertility treatment, the interest rose to about 41%. Yet amongst healthcare providers, most fertility centers choose not to offer gender selection and many doctors continue to voice their concerns as well[G4] . Most cite their belief that offering gender selection could create a particular bias or discrepancy between male and female children born. In reality, this belief is unfounded.
Most studies indicate that women are the primary decision-makers in couples seeking gender selection. Further, it has been shown that although amongst some ethnic groups there may be a strong bias toward choosing one sex over the other; this difference disappears when looking at larger groups of patients. Specifically, studies show that Caucasion Americans and European patients have a slight preference to choose girls over boys. By contrast, patients from Asia and Middle East have a stronger tendency toward selecting for sons over daughters. Aside from ethnic origin, it has been found that women who were a bit older, willing to pay for sex selection and had other children were more likely to request their next child be a girl. The end result is that although the technology has been readily available for over a decade now, the fear that it would contribute to any gender inequity is unfounded. As we move forward, I’ll continue to support my patient’s autonomy in these highly personal decisions. Here’s what we know about the current technology:
- Sperm selection—this involves separating the “male” sperm bearing the Y-chromosome from the “female” ones that carry the larger X-chromosome. Due to the difference in the size between these two chromosomes, “female” sperm are 2.8% heavier. Based upon this weight difference, they are able to be separated but with a more limited precision. The latest statistics[G5] indicate that X-enriched specimens contain ~88% female sperm and the Y-enriched specimen has about 74% male sperm. The cost of sperm separation combined with the lower pregnancy rate of non-IVF treatment have limited the enthusiasm for this technique.
- Embryo selection—is an add-on procedure to the IVF process. After the eggs have been fertilized, the embryos that are developing normally are able to be biopsied on day 3 after fertilization. The accuracy of the genetic testing is better than 98% and can also be combined with other screening tests to rule out conditions like Down’s syndrome. The results of the biopsies return before the embryos are selected for transfer into the recipient’s uterus. Embryos that are not selected are often frozen for future pregnancy attempts or donated to other couples that are seeking to become pregnant.