Multiyear outcomes using sibling oocytes demonstrates safety and efficacy of a simplified culture system consistent with use in a low-cost IVF setting

Research question: Can a novel closed simplified IVF culture system be used to achieve outcomes comparable to those obtained with intracytoplasmic sperm injection (ICSI) followed by conventional culturing? Design: This analysis is part of a non-inferiority prospective study comparing ICSI and a simplified culture system (SCS) for gamete fertilization in a selected group of patients. According to protocol, sibling oocytes in intact cumulus-oocyte complexes were randomly distributed between ICSI and conventional insemination in the SCS. For women, selection criteria included being under 43 years of age and at least six eggs at retrieval. An inseminating motile sperm count >= 1 million was required. The primary outcome measure was ongoing pregnancy rate (> 12 weeks) per cycle; secondary outcome measures included fertilization rate, miscarriage rate and implantation rate (ongoing pregnancy rate per embryo). Results: From January 2016 until December 2019, 653 SCS/ICSI cycles were performed yielding a total of 7915 oocytes. The fertilization rate was 61.1% and 50.4% for SCS and ICSI (P < 0.0001), respectively. The ongoing pregnancy rate was 32.0% for SCS and 36.7% for ICSI (P = 0.27). Implantation rate was 30.6% for SCS and 34.4% for ICSI (P = 0.35). The miscarriage rate was 7.5% and 6.5% for SCS and ICSI, respectively (P = 0.75). Conclusion: No difference was found in ongoing pregnancy rate, implantation rate and the miscarriage rate between SCS and ICSI in this selected patient cohort.