Pasternak MC, et al. - In this retrospective single-institution study, researchers investigated the prognostic value of embryo grading prior to biopsy and cryopreservation, or after cryopreservation and thaw, for pregnancy, live birth, and pregnancy loss rates after euploid SET. They analyzed 1123 euploid SET cycles. Of these, 771 resulted in pregnancy (68.7%); 614 SET resulted in live birth (54.7% of SET), and 157 patients (20.4% of clinical pregnancies) had a subsequent pregnancy loss. Embryos if received only A or B grading pertaining to the quality of the inner cell mass and trophectoderm, were deemed high grade; all others embryos were determined to be low grade. Those who had a high grade embryo prior to biopsy had significantly higher rates of clinical pregnancy, live birth, and no pregnancy loss amongst these patients, compared to those with a low grade embryo. For post thaw grading of embryos, the same was true and statistically significant. They observed significantly lower clinical pregnancy and live birth rates for embryos that were high grade prior to biopsy but low grade after thaw compared to embryos that were high grade at both times, or low grade prior to biopsy and high grade after thaw. A significantly lower live birth rate and higher pregnancy loss rate were evident for embryos that were low grade prior to biopsy and high grade after thaw compared to embryos that were high grade at both times. A significantly higher clinical pregnancy, live birth rate, and no pregnancy loss rate were observed for embryos that were low grade prior to biopsy and high grade after thaw compared to embryos that were low grade at both times. These findings support the predictive value of both pre-biopsy and post-thaw grading for obstetrical outcomes including clinical pregnancy, live birth, and pregnancy loss rates in women undergoing in vitro fertilization (IVF)/pre-implantation genetic testing for aneuploidy (PGT-A) with subsequent euploid SET.