Day 3 biopsy and blastulation rates

OBJECTIVE: To determine if blastomere biopsy affects the rate of blastulation as compared to intact embryos. STUDY DESIGN: Retrospective age-matched cohort study. RESULTS: Forty-one patients with 41 in vitro fertilization (IVF) cycles and 329 embryos who underwent cleavage-stage biopsy with preimplantation genetic screening using array comparative genomic hybridiza tion were compared to 41 IVF cycles with 352 embryos eligible for biopsy but who did not undergo biopsy January 2011–July 2013. The proportion of embryos that developed to the blastocyst stage was significantly lower in the case group than in the control group (46.5% vs. 59.9%; p=0.0134). This was most evident in the age group >35 years old (43.2% vs. 58.8%; p=0.035). No significant difference was detected in proportions that developed to fully expanded or hatching blastulation between cases and controls (28.0% vs. 24.4%, p=0.56). There was a statistically significant difference in the proportion of euploid embryos available for transfer when comparing day 3 vs. day 5 biopsy (20.9% vs. 13.1%, p=0.0003). CONCLUSION: Cleavage stage biopsy for genetic testing lowers the overall proportion of embryos that develop to the blastocyst stage by 25% (from 59.9% to 46.5%). When compared to trophectoderm biopsy, cleavage stage biopsy allows for a larger cohort of euploid embryos to be available for selection and transfer.