A 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), which can maintain a stable culture environment, have been developed for use in in vitro fertilization (IVF) treatment. Methods: In this retrospective cross-sectional study, data from 1200 women who visited the Creation and Love fertility center between April 2021 and October 2023 were reviewed. Among them, the electronic medical records of 400 women aged 22–45 years who underwent IVF treatment were selected and divided into two groups according to the type of incubator used: 100 in the TL group and 300 in the conventional incubator (CI) group, to evaluate differences in embryo development. Among these participants, pregnancy outcomes were assessed in 150 women who underwent day 3 (cleavage-stage) fresh embryo transfer. Controlled ovarian stimulation was performed using a standard antagonist protocol. The primary outcome was a good embryo rate, and the secondary outcomes were the clinical pregnancy rate and live birth rate. Results: The mean age of the study population was 34.6 ± 5.4 years. The groups had similar good embryo rates (67.7% vs. 65.5%, p = 0.84), clinical pregnancy rates (49.0% vs. 52.0%, p = 0.86), and live birth rates (35.0% vs. 42.0%, p = 0.76). Furthermore, subgroup analyses showed that the live birth rate in women aged ≥ 35 years 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 the CI during day 3 fresh-embryo transfer cycles, our study demonstrated a statistically significant increase in live birth rates among women ≥ 35 years in the TL group.