Sex Selection

Genetic Screening

Sex selection allows determination of the sex of the child to be born. Couples may be interested in selecting the sex of the child because a specific genetic mutation is known to be present in one of the parents, which can manifest itself with disease in male or female offspring only. For example, certain genetic disorders (e.g. Duchenne Muscular Dystrophy) result from a genetic mutation on the X chromosome, which is a sex chromosome. If an intended mother carries the mutation on one of her X chromosomes (although she is not affected with the disease), there is a 50% likelihood of having an affected male offspring, while no female offspring would be affected. In this situation, a couple may desire to select only female embryos to be transferred. If, on the other hand, an intended father is a carrier of a Y-linked mutation (e.g. a deletion leading to azoospermia), a couple may wish to perform sex selection for a female offspring, as female offspring (who do not have a Y chromosome) would not be affected, while male offspring may be infertile.

Testing for such mutations and the baby’s sex can be performed during pregnancy by invasive prenatal tests such as chorionic villus sampling (CVS) or amniocentesis. However, if an affected baby is detected the patient would require pregnancy termination (which may not be an option for some couples). Such a scenario becomes unlikely when sex selection is performed in advance.

Family Balancing

Sex selection may also allow couples to balance the number of male or female offspring in their family. For example, couples who have already had several children of only one gender (e.g. all girls), may be interested in having a child of the opposite gender next. If the sole purpose of having another child is to obtain the desired gender, and/or if a couple would consider terminating a pregnancy of the “wrong” gender (as determined by CVS or amniocentesis later on in the pregnancy), sex selection of embryos may be a reasonable option for that couple.

Technique

A variety of conventional and non-conventional methods exist for sex selection, all with limited success. Although not 100% accurate, the most accurate available method is PGD. With accuracy nearing 100%, PGD has been established as a safe and effective method for sex selection. CFG is delighted to offer couples sex selection by PGD.