Family Balancing & Gender Selection

Selecting the Sex of Your Baby
As with all biological traits, gender is genetically based. Females are characterized by the possession of two X chromosomes (XX), while males have one X and one Y chromosome (XY). Every cell in the body contains these chromosomes, and these two chromosome complements plus 22 other pairs are theoretically present in all the cells of a normal pre-implantation embryo. One of each chromosome pair is of maternal origin (from the egg) while the other is of paternal origin (from the sperm).

Theoretically, sex determination can be accomplished in one of two ways:
a) separating the X- and Y-sperm and using either fraction for assisted conception, or

b) genetic analysis of embryos prior to implantation (called PGD), followed by transfer of either XX or XY embryos.
Separation of X- and Y-bearing sperm prior to assisted conception has met with limited success, with no guarantee of the desired sex being obtained. On the other hand, genetic analysis has proven to be much more accurate, and application of genetic testing to identify XX (female) and XY (male) embryos is the method of choice for gender selection at New York Fertility Institute. During this analysis, the normality of other chromosomes can also be checked, thus helping to ensure that healthy embryos of the desired sex are transferred.