Journal of Fertilization: In Vitro - IVF-Worldwide, Reproductive Medicine, Genetics & Stem Cell Biol
Open Access

Abstract

Clinical Pregnancy Rates after Elective versus Non-Elective Single Embryo Transfer in PGS Cycles

Oleksii O Barash, Kristen A Ivani, Susan P Willman, Mary D Hinckley, Deborah S Wachs, Evan M Rosenbluth, Sara Reid and Louis N Weckstein

Objective: The objective of this study was to evaluate ongoing clinical pregnancy rates after elective single embryo transfer (eSET) versus non-elective single embryo transfer (non-elective SET) and compare them to ongoing pregnancy rates after double embryo transfer (DET) in IVF cycles with preimplantation genetic screening (PGS). Design: A retrospective study of SNP PGS outcome data from blastocysts biopsied on day 5 or day 6 was conducted to identify differences in ongoing clinical pregnancy rates between study groups. Settings: Large private IVF practice. Materials and methods: 676 cycles of IVF treatment (591 patients) with PGS between January 2013 and July 2016 followed by 658 FETs were included in the study (569 SETs and 89 double embryo transfers). 4102 embryos were vitrified after the trophectoderm biopsy, and selected embryos were subsequently thawed for a hormone replacement frozen embryo transfer (FET) cycle. 415 SETs were elective (two or more euploid embryos were available) and 154 SETs were non-elective (only one euploid embryo was available). Cumulative live birth rates were assessed by Kaplan-Meier function. Results: Our data demonstrated no statistically significant difference in clinical outcomes between the study groups: the ongoing pregnancy rate after an elective SET was 61.0% (253/415) and 53.3% (82/154) after a nonelective SET. Moreover, the ongoing pregnancy rates in a group of patients who had elective SET were not statistically different among different age groups (ongoing PR ranged from 42.3% to 56.1%). Similar results were obtained in a group of patients with non-elective SET (ongoing PR ranged from 56.1% to 66.1%). An increase in the total number of available euploid embryos from 2 to ≥ 5 embryos did not affect ongoing pregnancy rates after SET: 58.2% (53/91), 68.4% (67/98), 52.9% (36/68) and 61.4% (97/158), respectively, χ2=2.087, p=0.1486. Cumulative live birth rate after two consecutive SETs is equivalent to live birth rate after DET: 74.3% and 72.9%, respectively. Conclusion: Analysis of the data proved the effectiveness of single embryo transfers in IVF PGS cycles regardless of maternal age or total number of euploid embryos available for transfer. In order to maintain high ongoing pregnancy rates and reduce multiple gestation rates, single embryo transfer should be imperative in PGS cycles.