What is PGD/PGS?

What a difference a couple of weeks can make. Several weeks ago the Red Sox seemed doomed to another “close but no cigar” type of season and here they are in the World Series. Over October 12-16th the annual meeting of the ASRM was here in Washington DC. It is tough to have the meeting in one’s hometown as working while attending the daily meeting can be problematic…although not as problematic as going out at night to parties and then working the next AM. However, as a fairly boring the Eagle Scout straight arrow nice guy who prefers to be in bed a by 10 PM I really wouldn’t be able to comment about what went on after dark at the ASRM. But if you want to know if your RE behaved, please feel free to contact me and I can elaborate on all the juicy details.

One of the highlights of the meeting was a lunch debate between Santiago Munne, PhD and Marcus Hughes, MD, PhD on the topic of whether preimplantation genetic diagnosis (PGD) for aneuploidy (also known as preimplantation genetic screening (PGS)) will become standard of care in IVF. Both are excellent scientists, although I must admit that Dr. Hughes is, in my book, one of the smartest human beings on the planet. Over the next few blog posts I want to address the issue of IVF with PGD/PGS and after keeping you all (and my Mom) in suspense I will tell you about the outcome of the debate.

So please accept my humble apologies for being slow to post recently…it took me a while to recover from Club Luv at the ASRM (just kidding). Here is the latest Question of the Day from the book that is being promoted on WTOP here in Washington. How about some more 5-star reviews on Amazon ? (just thought I would ask).

72. What are PGD and PGS?


Preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) are techniques that provide diagnostic information concerning an embryo prior to its transfer to the uterus. The vast majority of PGD and PGS procedures are performed by removing 1 or 2 cells (or blastomeres) of a 6- to 8-cell embryo on day 3 of embryo culture following IVF. These cells are rapidly analyzed, and on day 5 the unaffected embryos are selected for embryo transfer. PGD was first performed in 1989 in an effort to avoid the transfer of embryos that carried serious genetic disorders (for example, cystic fibrosis). Thus couples who undergo PGD do not have infertility but rather are at risk for passing a genetic disease to their children. A wide range of single-gene and chromosomal disorders can now be diagnosed with PGD, including autosomal recessive diseases (e.g., cystic fibrosis), X-linked recessive diseases (e.g., hemophilia, Duchenne muscular dystrophy), autosomal dominant diseases (e.g., Huntington’s disease), and chromosomal rearrangements (e.g., balanced translocations). PGS is similar to PGD, but refers to screening of embryos produced in the course of fertility treatments. Thus couples who undergo PGS include infertile patients without an underlying genetic problem. PGS is performed in an attempt to identify those embryos that are genetically abnormal so that improved embryo selection will—ideally—result in improved pregnancy rates and lower miscarriage rates.