Higher pregnancy rates are observed after single euploid frozen embryo transfer utilizing time-lapse monitoring technology when compared to traditional embryo incubation

One of the challenges in assisted reproductive technology is to identify and select embryos with the highest developmental potential, with a goal of improving pregnancy and ultimately live birth rates. Preimplantation genetic testing for aneuploidy (PGT-A) with next generation sequencing (NGS) has improved pregnancy rates by transfer of euploid embryos, however room for improvement remains. Time-lapse monitoring (TLM) is a non-invasive system that allows for continuous embryo imaging, maintenance of optimal culture conditions, and detection of developmental events that may lead to improved outcomes. Our objective is to determine whether TLM at the time of embryo development leads to improved pregnancy rates over traditional embryo incubation. Retrospective cohort study at a large, private fertility center. A comprehensive electronic chart review was performed. All patients utilizing the TLM device (Embryoscope®, Vitrolife, Sweden) at a single IVF center from 2018 through March 2019 were analyzed. All patients who underwent a frozen embryo transfer (FET) of a PGT-A analyzed day 5, 6, or 7 embryo of good or fair quality were included in the study. Statistics were performed using 2-tailed Chi-square analysis where statistical significance was set at p values <0.05. A total of 952 patients were identified; 83 (8.7%) used the TLM device. Of all patients, 942 (98.9%) had only a single thaw cycle and transfer. Focusing on patients with only a single thaw cycle, thereby isolating the analysis to the best overall embryo(s), the overall pregnancy rate was 644/942 (68.4%). Of these patients, the pregnancy rate of patients using TLM was significantly higher than those using traditional incubation (59/73, 80.8% versus 585/869, 67.3%; p<0.05). Looking only at patients that had an elective single embryo transfer (eSET), the overall pregnancy rate was 639/869 (73.5%). Pregnancy rates were higher after transfer of embryos created with TLM technology compared to traditional incubation (54/67, 80.6% versus 585/869, 67.3%; p<0.05). Combining patients that had both a single thaw cycle as well as an eSET, the overall pregnancy rate was 636/933 (68.2%) and TLM embryos had a significantly higher pregnancy rate over embryos from traditional incubation (51/64, 79.7% versus 585/869, 67.3%; p<0.05). TLM technology at the time of embryo development yields a statistically higher pregnancy rate as compared to embryos created with traditional incubation. This is especially true when the best embryo(s) is(are) selected for transfer as well as when only an eSET is performed. Given the significantly improved pregnancy rates, TLM incubation of embryos should be considered as an alternative to traditional incubation.