High relative deoxyribonucleic acid content of trophectoderm biopsy adversely affects pregnancy outcomes

Abstract

Objective: To evaluate the association between relative DNA content of the trophectoderm biopsy and pregnancy outcomes.

Design: Retrospective cohort study.

Setting: Academic-affiliated private practice.

Patient(s): This study included patients undergoing their first single embryo transfer after trophectoderm biopsy and comprehensive chromosome screening (CCS) at a single center between January 2010 and February 2014.

Intervention(s): In phase 1 of the study, a standard curve was developed to estimate the relative DNA content of trophectoderm biopsies. Phase 2 of the study examined reproductive outcomes in patients undergoing single embryo transfer after trophectoderm biopsy and CCS. Samples were divided into quartiles according to their relative DNA content, and clinical outcomes were compared.

Main outcome measure(s): Chemical pregnancy rate, clinical implantation rate, ongoing pregnancy rate, live birth rate.

Result(s): The quartile of highest relative DNA content had a significantly lower live birth rate when compared with the other three quartiles (relative risk 0.84, 95% confidence interval 0.75-0.95). There was no difference between the quartiles regarding age, body mass index, ovarian response, or endometrial thickness. Among those patients who had a live birth, there was no difference in hCG levels, gestational age at delivery, or birth weight with respect to biopsy DNA content.

Conclusion(s): Trophectoderm biopsies with the highest relative DNA content are associated with lower live birth rates after single embryo transfer. Possible explanations for this phenomenon include diminished accuracy of the euploid diagnosis vs. a mechanical impact of the biopsy. Regardless of the cause, the outcomes emphasize the importance of obtaining appropriately sized trophectoderm biopsies for CCS.

Keywords: Comprehensive chromosome screening; IVF; preimplantation genetic diagnosis; trophectoderm biopsy.