Trophectoderm Biopsy & New PGS
The Center for Human Reproduction’s Dr. David H. Barad explains the new form of pre-implantation genetic screening (PGS) with trophectoderm biopsy performed on day-5 embryos (blastocysts). Though considered technically superior to the original PGS, there are unanswered questions about whether the new PGS is accurate, and whether it improves IVF outcomes.
What’s done today is called a trophectoderm biopsy. You can think of that as a biopsy that’s done on a blastysis (five-day embryo) – which looks like a little ball – inside that ball is an inner cell mass that’s going to be the baby. The biopsy is done not on the inner cell mass, but on that outer part that is destined to be the placenta. That is why it is touted as being safer, because you are not biopsying the baby. The technical ways of testing those chromosomes have progressed over time so that they’re highly accurate in telling you the genetics of the cells that have been biopsied. So, we have a combination of something which is theoretically much safer and technically much more accurate, which should translate into a better test.