Four on Ice

On Wednesday, the embryologist from Fertility Associates called with an update on our embryos. To be eligible to be biopsied (sampled) for PGD, they need to develop to the blastocyst stage of development. This generally occurs around day 5 or 6 of development, at which point the embryo is comprised of approximately 200 cells. They said that of our nine embryos, one was developed enough to biopsy for PGD so far, and so had been biopsied and would be frozen that day. Four more embryos were looking promising for biopsy the following day. The remaining four weren’t looking as good, and while it is likely they wouldn’t continue to develop, they would continue to monitor them and make a decision regarding their viability the following day. On Thursday, three more embryos had been biopsied and frozen, and one more was still ‘trying’, so the embryologist said they’d give it until Friday to see if it too reached the blastocyst stage, and would call then to let us know.

Development of a blastocyst embryo

Today, the embryologist called to say the final embryo didn’t make the cut, which leaves us with four embryos in total biopsied and frozen, a great result. For each embryo, there is a 50/50 chance that they do not have the gene for SCA3, and will be suitable for implantation. We are cautiously optimistic that four embryos gives us a reasonable chance of one with a clear result. They sent the samples to the lab today for the genetic testing, and advised us that the results will take between 2-6 weeks. 

Further information
Blastocyst embryos are graded A-C according to their appearance and rate of development. They contain two groups of cells, one that develops into the foetus (the inner cell mass), and one that develops into the placenta (the trophectoderm). Embryos are given one grade for each of the two groups of cells. I asked how ours were graded, and three of them are graded AB, which is very good, and one is BC which isn’t as good, but embryos with that grade can still develop normally. The trophectoderm is the part which is sampled for PGD.

Diagram showing biopsy of the blastocyst's trophectoderm for PGD