Endometrial preparation by hormone replacement and day 6 biopsied euploid blastocyst transfer (bt) increases the risk of miscarriage compared with an ovulatory cycle and day 5 biopsied euploid bt

Accepted theory posits that more than half of the causes of pregnancy loss involve aneuploidy of the transferred embryos or blastocysts. This explanation has recently come into question, however, due to the clinical application of preimplantation genetic testing for aneuploidy (PGT-A). In an effort to further elucidate the risk factors for miscarriage, we retrospectively evaluated the clinical data between ongoing pregnancies and cases of miscarriage following euploid blastocyst transfer.