Even more potentially good news today! Heidi has seven fertilized eggs out of the nine retrieved. That is a pretty good yield. Tomorrow we will perform a genetic test that measures a gene known as human leukocyte antigen-G (HLA-G) in the culture media surrounding Heidi's two-day-old embryos. This test, although not as conclusive as CGH testing, will provide us with a good measure of the embryos' potential to produce a viable pregnancy.
Two days from now, we will grade the embryos microscopically. The method we use is called the Graduated Embryo Scoring (GES) system, which we introduced in 2000. We culture and assess each embryo separately, determining if they reach daily developmental milestones—and we give them a score of up to 100 points. The GES method differs from other traditional grading systems in which a single assessment is made on groups or clusters of several embryos.
Heidi herself seems to be in a good place. I believe that she understands that everyone, including Darren, is doing their very best for her and that we are all guardedly optimistic. She is doing so well that she went off with Darren to a business meeting today.
Now we need to wait for a few days so that we can better assess embryo quality. Heidi's embryos will ultimately get the opportunity to prove themselves by reaching the blastocyst stage of development before being transferred to her uterus. By allowing embryos to develop to this stage, many of the poorer quality ones are culled, making it unnecessary to transfer too many at one time.
If you've ever wondered why it is so difficult to answer questions relating to success rates with IVF, this is the reason: It is truly a work in progress. But as each embryo reaches a milestone, the future becomes clearer.