Pre-Implantation Genetic Diagnosis (PGD) & Screening
A procedure that was first performed in 1989, pre-implantation genetic diagnosis (PGD), has assisted couples at risk of carrying life-threatening genetic diseases from potentially passing such afflictions to their offspring.
PGD can be used only in conjunction with in vitro fertilization (IVF). Because IVF allows examination of an embryo outside the womb, specialists can take sample cells for analysis and detection of known genetic diseases or chromosomal abnormalities. This allows genetics experts to identify embryos with irregularities.
While PGD has been used in treating women with recurring miscarriages in hopes of identifying embryos with normal chromosome structure and number for implantation, the effectiveness of this approach is a topic of ongoing debate and research.
Prior to PGD, the diagnosis of genetic disease was performed by testing a fetus through amniocentesis or chorionic villus sampling (CVS), in which cells from the placenta are sampled and tested early in a pregnancy.