In medicine and (clinical) genetics preimplantation genetic diagnosis (PGD) is a method to test embryos for genetic disorders before they are reimplanted in the uterus.

When a genetic disorder occurs in a family, the parents are usually reluctant to attempt pregnancy again, given the 25-50% chance (dependent on the type of disorder) of recurrence after a previous child has been affected.

A solution to the problem is the use of in vitro fertilisation (IVF) with testing of each embryo at blastocyst stage for the presence of the disease-causing genes. Although there remains a small chance of false negative results, this would eradicate the possibility of recurrence of the disease in question.

In theory, PGD could be used for sex selection, a very controversial procedure to ensure that offspring is of one particular sex, or selection on the presence or absence of other genetically determined traits.

External links

• Preimplantation genetic diagnosis and sex selection (http://www.thedoctorslounge.net/fertilounge/articles/pgd/index.htm)
• Use of PGD in infertility (http://www.infertile.com/treatmnt/treats/pgd.htm)
• Religious views on PGD (http://www.religioustolerance.org/abo_pgd.htm)