Sex Selection IVF and Family Balancing
Sometimes families desire a child of certain sex (Gender Selection IVF) a. to avoid a sex linked genetic disorder or b. to parent a child of certain sex e.g female after they had a child or children of the opposite sex e.g male, especially as families want to have a limited number of children (2.03 per woman).
The sex of the embryo can be determined through sorting the X (female) from male (Y) sperm or by determining the sex chromosome composition of the embryo (female XX or male XY). Sorting sperm alone is not an accurate method for sex selection and cannot be used alone for sex selection in couple desiring close to 100% accurate selection.
Who is a good candidate for sex selection procedures?
Women with good ovarian reserve and younger than 40 are more likely to deliver a baby after sex selection. Success rates of IVF are significantly lower in women >40 year old mainly due to chromosomal abnormalities of the egg and reduced response to ovarian stimulation. Women producing a good number of eggs with normal chromosomes are more likely to find embryos of the desired sex that can implant and achieve pregnancy.
How is sex selection done?
Following ovarian stimulation, egg retrieval and fertilization embryos are biopsied on day 3 or day 5 (blastocyst stage). The cells are tested for the X and Y chromosomes. One or more embryos of the desired sex are transferred into the uterus.
To enrich for the desired sex, the sperm is sorted prior to sex selection IVF and the desired type of sperm X or Y is used for fertilization.