Genetic Testing

Pregnancy Rates in In Vitro Fertilization Are Superior When Trophectoderm Biopsy Is Done Only on Hatching Embryos [40K]

Obstetrics & Gynecology

Sonali Singh, MD, Elie Hobeika, MD, and Michael Lawrence Traub, MD


INTRODUCTION: In-vitro fertilization (IVF) with trophectoderm embryo biopsy and pre-implantation genetic screening (PGS) for aneuploidy, followed by elective single frozen embryo transfer (eSET) is becoming increasingly popular. However, embryos can be biopsied at various stages of blastocyst development. No studies to date have specifically investigated differences in pregnancy outcomes by timing of embryo biopsy.

METHODS: Retrospective study of patients (n5363) at a single IVF center between January 1, 2013 and December 31, 2016 undergoing eSET with PGS. Embryo grading assessed at the time of biopsy and transfer. Pregnancy rates analyzed by embryo expansion, inner cell mass and trophectoderm grading. Statistical analyses performed by ttest, chi squared, Mann Whitney and Fischer exact tests. Interactions between embryo expansion, inner cell mass and trophectoderm grading were analyzed by 2-way ANOVA. IRB approval obtained.

RESULTS: Implantation, clinical pregnancy and live birth rates improved significantly (P5.0001) and pregnancy loss decreased substantially (P,.001) with increased embryo expansion and if embryos were hatching at the time of embryo biopsy. For non-expanded or expanded embryos at biopsy, that later hatched at the time of eSET, pregnancy outcomes remained poor (live births 0% and 5.9%). Pregnancy rates from eSET with PGS where embryos were allowed to hatch, were far better than eSET of embryos without PGS.

CONCLUSION: Embryos biopsied before they are hatching have extremely poor pregnancy outcomes regardless of how much they expand by the time of eSET. The embryo biopsy on a non-hatching embryo seems to significantly damage the embryo. IVF labs should wait until embryos hatch before performing trophectoderm biopsy.


Financial Disclosure: The authors did not report any potential conflicts of interest.


© 2019 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.

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