Q. My husband and I are each aware of some serious diseases that run in our families. We read that PGD (preimplantation genetic diagnosis) can help select healthy embryos. What kinds of conditions can PGD test for? Should we look into this test even if we don’t need fertility treatments?
A. PGD involves removing a cell from a day-3 embryo and performing genetic tests to determine if it is a “healthy” embryo. There are a wide range of opinions as to who can benefit from this procedure, which unfortunately can be inaccurate and cost thousands of dollars. It definitely benefits those would-be parents who don’t want to pass on a terrible genetic disease such as muscular dystrophy or Huntington’s disease. There are dozens of such entities that we can now test for prior to conception (or preimplantation). The differences of opinion about using this test come when there are other tentative indications for it, such as advanced maternal age, recurrent pregnancy loss, and multiple IVF failures. The problem is that currently we can only study a small percentage of an embryo’s chromosomes, so we can’t really determine if it’s truly genetically healthy or not. For this reason, most studies have not shown PGD to be significantly beneficial unless it’s done for a specific genetic problem. Ask your doctor whether the diseases that run in your families are diseases that can be specifically screened for with PGD before deciding whether or not to proceed.