Comparison of Embryo Development and Pregnancy Outcomes Between Time-Lapse and Conventional Incubators: A Single-Center Cross-Sectional Study

Background: In recent years, time-lapse incubators (TLs) with the ability to maintain a stable culture environment have been developed for in vitro fertilization treatment. Methods: In this retrospective cross-sectional study, data from 1,200 women who visited the Creation and Love fertility center, between April 2021 and October 2023 were reviewed. Among them, electronic medical records of 400 women aged 22-45 who underwent in vitro fertilization treatment were selected and divided into 2 groups according to the type of incubator used: 100 in the TL group and 300 in the CI group to evaluate differences in embryo development. Out of these participants, pregnancy outcomes were compared in 150 who underwent fresh-embryo transfer. Controlled ovarian stimulation was performed by standard antagonist protocol. The primary outcome was live birth rate, and the secondary outcome was good embryo rate. Results: The mean age of the study population was 34.6±5.4. Groups had a similar good embryo rate (67.7% vs. 65.5%, p=0.84), clinical pregnancy rate (49.0% vs. 52.0%, p=0.86) and live birth rate (35.0% vs. 42.0%, p=0.76). Furthermore, subgroup analyses of the live birth rate in women aged >35 was higher in the TL group than the CI group (38.0% vs. 23.4%, p=0.03). Conclusions: Based on the comparative analysis of live birth rates between women cultured using TLs and those using CI during 3-day fresh embryo transfer cycles, our study demonstrated a statistically significant increase in live birth rates among women >35 yr of age in the TL group.