Study Raises Questions About Popular Genetic Test for ‘Abnormal’ Embryos

However the brand new examine additionally reveals the constraints of transferring such embryos. A overwhelming majority of the 144 embryos transferred by the group had just one or two chromosomal abnormalities, however the transfers led to 11 miscarriages along with the eight reside births.

“There’s a variety of miscarriages in that ratio,” mentioned Laura Hercher, director of pupil analysis on the Sarah Lawrence School genetic counseling program.

The PGT-A take a look at is used to display for aneuploidy, which is when an improper variety of chromosomes — both too few or too many — is detected in sampled cells. An irregular variety of chromosomes can, in critical circumstances, result in genetic disabilities, like Down syndrome. Extra typically, the unsuitable variety of chromosomes can result in failed pregnancies, both by stopping embryos from implanting or by inflicting miscarriages.

However the issue with PGT-A, the authors of the examine argue, is that it gives an incomplete image that’s typically interpreted as a really definitive end result. The take a look at depends on sampling a handful of cells from the outer shell of the creating embryo and testing to see if every one has 23 pairs of chromosomes.

“The purpose of PGT was to pick embryos that may give any individual a greater likelihood of reaching being pregnant,” mentioned Dr. David Barad, an OB-GYN on the Heart for Human Copy and a co-author of the examine. “However doing genetic testing doesn’t make embryos higher, it simply form of provides us some thought of who they’re.”

Although shifting forward with utilizing these embryos with abnormalities could include some danger, the authors of the brand new examine, all of whom have been related to the clinic doing the transfers, argue that viable embryos are at the moment being disregarded, leaving many ladies to imagine they haven’t any different choices to attain a being pregnant.

“The miscarriage price is roughly what one expects at such superior age,” Dr. Norbert Gleicher, director of the clinic and a co-author of the examine, mentioned by e mail. He added: “Ask ladies what they like. A danger of miscarriage or no likelihood of getting a child in any respect. The reply might be clear.”