Gender Selection (Sex Selection)
Gender selection is a technique which allows couples to
increase the odds of delivering a child of a particular sex. As discussed above, certain medical indications may exist which require gender selection in order to ensure the well-being of a child (see PGD/sex-linked disorders). Couples without a specific sex-linked genetic mutation may pursue gender selection for the purpose of family balancing.
Gender selection can be performed with a variety of techniques, which vary in accuracy and success. The simplest method is the Ericksson sperm washing/insemination protocol, which is easy to perform and affordable, but achieves limited accuracy. A more involved method of sperm selection uses the Microsort® technology. In this protocol, X-chromosome bearing sperm is separated from Y-chromosome bearing sperm using a flow cytometer. Accuracy of the Microsort® technology is limited and depends on the gender desired (female more accurate than male). Since the amount of sex-selected sperm available after sorting is often unsatisfactory for insemination, in vitro fertilization is generally the procedure performed in conjunction with the Microsort® technique.
The most accurate method for gender selection available today involves preimplantation genetic diagnosis (PGD). PGD may be combined with either the Ericksson and/or the Microsort® technique(s) to improve sperm selection, however differs from the abovementioned protocols in that it allows definitive determination of an embryo's gender prior to implantation in the uterus. After embryos are conceived through IVF, each embryo is biopsied prior to embryo transfer, and a specific chromosomal test is applied in order to determine gender (XX=female, or XY=male). Other chromosomal abnormalities may also be ruled out with the biopsy. Then, chromosomally normal embryos of the desired gender (only female embryos, for example), are transferred into the uterus. Accuracy rates reach 99% or higher. The technique is safe and highly successful.
