Day-3 embryo morphology predicts euploidy among older subjects
Received 30 October 2006; received in revised form 29 January 2007; accepted 29 January 2007. published online 24 April 2007.
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 subjects (<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.
ABSTRACT