The pivotal role of the number of transferred embryos in oocyte donation cycles: A retrospective cohort study

Abstract

This research aimed to show the role of the number of transferred embryos on pregnancy outcomes of the oocyte donation cycles (ODC). This retrospective cohort study included 122 ODCs performed at a private in vitro fertilization (IVF) center between 2020 June - 2021 January. Cases with severe male infertility, tuboperitoneal, and endometrial factors were not included in the study. The median (interquartile range) recipient age was 43 (30–54) years. ODC results revealed that 10.7% of the cases were negative, 4.9% were biochemical pregnancies, and 84.4% were clinical pregnancies. Pregnancy outcomes were checked; miscarriage, preterm, and term delivery rates were 5.7%, 3.9%, and 90.4%, respectively. The rate of recipients for the younger than 40 years was 32%, between the 40–44 years was 27%, and between 45–54 years was 41% respectively. Statistically significant difference was not observed between age groups in terms of endometrial thickness (p = 0.059), number of transferred embryos (p = 0.857), number of ODC attempt (p = 0.666), live birth rate (p = 0.1), and other pregnancy outcomes (p > 0.05, for all). A total of 96 (78.7%) embryo transfers (ET) resulted in a live birth. In 8.2% (n=10) of cases, single embryo transfer (SET) and in 91.8% (n=112) of cases, double embryo transfer (DET) was performed. The number of embryos transferred was statistically significantly higher among cases that resulted in live births compared to cases without live births (p = 0.002). Significant difference was not found in terms of the recipient age (p = 0.392), male age (p = 0.108), endometrial thickness (p = 0.478), and the number of attempt (p = 0.777) between cases resulted in live birth or not. The only parameter that affects the live birth rates in ODC is the number of transferred embryos.