Selecting the best possible embryo to implant in a woman undergoing in vitro fertilization (IVF) is a complicated task. As success rates for IVF have improved, many clinics now implant a single embryo during an IVF cycle—with the goal of avoiding a multiple pregnancy—and the responsibility of selecting the embryo falls to the embryologist. To determine the quality and viability of an embryo, embryologists typically examine specific features of the embryos using a light microscope. In addition, specialists can use data from preimplantation genetic testing for aneuploidy (PGT-A), a test of whether cells from the embryo at the blastocyst stage have a normal or abnormal number of chromosomes. However, this crucial test carries the risk of false positives (which could lead to discarding a normal embryo) and false negatives (which could lead to transferring an embryo with a chromosomal abnormality).
* This article was originally published here