Polar bodies are the by-products of the egg’s division during meiosis. As an egg matures, it goes through a two-step division process, dividing once at the time when ovulation would occur and again at the time of fertilization. The two polar bodies are the by-products of this division, and are essentially discarded by the egg. By analyzing the polar bodies, it is possible to infer the genetic status of the egg. Therefore, polar body analysis allows us to test the mother’s genetic contribution to the embryo.

When testing for a genetic disorder, it is critical to have information from both polar bodies to get a clear picture of the genetic make-up of the egg. The first polar body is released by the egg when ovulation would occur. The second polar body is released upon fertilization. When testing the polar bodies for chromosomal aneuploidy, such as Down syndrome, both polar bodies are removed together the day following the egg retrieval (Day 1). When testing for single gene disorders, such as cystic fibrosis, the polar bodies are removed separately. The first polar body is removed the day of the egg retrieval (Day 0) and the second polar body is removed on Day 1.

Studies have shown that PGD for aneuploidy by embryo biopsy alone is not highly accurate. Testing the polar bodies in addition to the embryo is the preferred method of testing for aneuploidy conditions.

 

Next Steps:

Please review our PGD information packet and pamphlets and contact our genetic counselors with any questions or inquiries regarding our PGD program.