Multinucleation of a sibling blastomere on day 2 suggests unsuitability for embryo transfer in IVF-preimplantation genetic screening cycles.

OBJECTIVE

To evaluate the impact of multinucleation of a sibling blastomere of day 2 embryos on the rate of aneuploidy detected by day 3 preimplantation genetic screening (PGS) biopsy and the effect on subsequent implantation and pregnancy rates.

DESIGN

Retrospective cohort study.

SETTING

University-based IVF center.

PATIENT(S): A total of 141 couples undergoing their first IVF-PGS cycle for idiopathic recurrent pregnancy loss (RPL) or multiple failed IVF implantations.

INTERVENTION(S): Biopsy of single-nucleated blastomeres for PGS analysis of chromosomes X, Y, 13, 15, 16, 17, 18, 21, and 22 by fluorescence in situ hybridization.

MAIN OUTCOME MEASURE(S): Aneuploidy, implantation, and pregnancy rates.

RESULT(S): PGS revealed an increased incidence of aneuploidy when comparing multinucleated day 2 embryos with single-nucleated embryos (85% vs. 78%; relative risk 0.92 (95% confidence interval 0.84-1.00). Transfer of single-nucleated euploid embryos resulted in clinical pregnancy and implantation rates of 28% and 24%. Transfer of multinucleated euploid embryos resulted in no implantations.

CONCLUSION(S): The presence of multinucleated blastomeres on day 2 of embryo development, 1 day before biopsy, predicts an increase of aneuploidy and poor pregnancy outcomes in IVF-PGS cycles.