The sex of an embryo is determined by the chromosomes carried by the sperm. A sperm can carry either the X or the Y chromosome. The woman’s egg only contributes the X chromosome to the fertilized embryo. The presence of the Y chromosome in the sperm will create a male baby (XY). Two X chromosomes – one X from the sperm and one X from the egg – will produce a girl baby (XX).
Sex Selection in Conjunction with IVF Procedure
PGS/NGS testing takes place in conjunction with IVF in a controlled laboratory setting. Several days after fertilization of the patient’s eggs in vitro, 3-6 cells are removed from each of the embryos that are at the blastocyst stage.