Time-Lapse Incubation for Embryo Culture-Morphokinetics and Environmental Stability May Not Be Enough: Results from a Pilot Randomized Controlled Trial

Background: Does the Time-lapse Incubator (TLI) add value to reproductive outcomes when its two components, undisturbed culturing and morphokinetic embryo grading, are separated. Methods: A prospective pilot, randomized, controlled, double-blinded, single-center study was conducted during the years 2016–2020. In total, 102 patients were randomized into three groups: (1) conventional incubation with morphological evaluation only (n = 34), (2) TLI with both morphological and morphokinetic evaluations (n = 32), and (3) TLI with morphological evaluation only (n = 36). All arms were cultured in ESCO-MIRI^® incubators. A total of 1061 injected mature oocytes were evaluated (420 in arm 1, 285 in arm 2, and 356 in arm 3). The primary outcome was live birth rates. Secondary outcomes included clinical and cumulative pregnancy rates as well as embryo quality. Embryos in arm 3 were retrospectively evaluated for their morphokinetic score. Results: No significant difference was found in the live birth rate for single embryo transfer cycles (SET) (35% vs. 31.6% vs. 24%, p = 0.708) or double embryo transfer (DET) cycles (41.7% vs. 38.5% vs. 36.4%, p = 0.966). Comparable pregnancy rates, clinical pregnancy rates, and cumulative pregnancy were found for similar top-quality embryos for days 2, 3, and blastocyst stages across groups. A similar number of embryos were suitable for either transfer or cryopreservation within the different groups. For 62.8% of the embryos in arm 3, the morphokinetic and morphologic evaluations were similar. In only 2/36 (5.6%) treatment cycles, the use of morphokinetic scoring may have helped the patient avoid undergoing an additional treatment cycle. In the other cases, morphokinetic scoring would not have changed the end point of pregnancy. Conclusions: The two components of the TLI system—undisturbed culturing and morphokinetic embryo grading—do not appear to have a significant additional value in reproductive outcome, although these results should be validated by an RCT.