Day-3 embryo morphology predicts euploidy among older subjects

Objective: To evaluate whether day-3 embryo morphology predicts euploidy. Design: Retrospective. Setting: Private IVF center. Patient(s): Subjects (n = 144) undergoing in vitro fertilization and preimplantation genetic diagnosis (PGD). Intervention(S): Translate day-3 embryo characteristics into a standardized score. Main outcome measure(s): Day-3 embryo morphology score and PGD fluorescence in situ hybridization results for chromosomes: 13, 15, 16, 17, 18, 21, 22, X, and Y. Result(s): Of 1,043 biopsied blastomeres, 67% (n = 696) were chromosomally abnormal. Women with advanced maternal age (AMA) were 1.3 times more likely to have chromosomal errors(95% CI 1.1-1.4) than younger sub jects (< 38 years old). Morphology predicted PGD results in the AMA group (n = 553), but not in younger women. Fragmentation predicted euploidy in both the younger and the AMA group, but cell number did not. Conclusion(s): Day-3 embryo morphology selects for euploidy among AMA subjects but not among younger women who may have other factors responsible for embryo dysmorphism. However, cellular fragmentation is a sensitive proxy for selecting chromosomally normal embryos in both age groups. It is unclear that PGD-aneuploidy screening is a better tool for selecting which embryos to transfer than the standard approach of using day-3 embryo features, particularly among older women, a group for whom this technology is targeted.