Impact of multiple blastocyst biopsy and vitrification-warming procedures on pregnancy outcomes

Abstract

Objective: To assess the impact of multiple blastocyst biopsy and vitrification-warming procedures on clinical outcomes.

Design: Retrospective study.

Setting: Private fertility clinic.

Patient(s): Preimplantation genetic diagnosis (PGD) patients undergoing comprehensive chromosome screening, including monogenic disorder and chromosome rearrangement cases.

Intervention(s): Warming and transfer of euploid blastocysts biopsied and vitrified-warmed once (group 1 [G1, control]; n = 2,130), biopsied once but vitrified-warmed twice (group 2 [G2]; n = 34), or biopsied and vitrified-warmed twice (group 3 [G3]; n = 29).

Main outcome measure(s): Thaw (for transfer) survival rate and clinical pregnancy rate (CPR).

Result(s): The thaw survival rates were 98.4% for G1, 97.3% for G2, and 93.3% for G3, with once biopsied and vitrified-warmed embryos being significantly higher than twice biopsied and vitrified-warmed embryos (G1 vs. G3; P=.032). There was a slight reduction in CPR with an additional vitrification-warming (G1 54.3% vs. G2 47.1%) and larger reduction with an additional embryo biopsy (G2 47.1% vs. G3 31.0%), but neither difference was statistically significant. However, the combined effect of both additional biopsy and vitrification-warming resulted in a significantly reduced CPR (G1 54.3% vs. G3 31.0%; P=.013).

Conclusion(s): This study indicates that blastocysts biopsied and vitrified-warmed twice have reduced clinical outcomes compared with blastocysts biopsied and vitrified-warmed once. PGD patients should be advised that performing a second biopsy and vitrification-warming in cases of failure to obtain a result from initial biopsy will reduce the chance of pregnancy. Patients with inherited disorders may elect to proceed with the second biopsy and vitrification to avoid transfer of embryos with the genetic condition.

Keywords: Blastocyst; preimplantation genetic screening; trophectoderm biopsy; vitrification.