Non-medical oocyte cryopreservation at a single center in Japan: 8 years of experience.

Purpose: Increasing numbers of women are opting to undergo non-medical oocyte cryopreservation (NMOC). In this report, we present experience at our clinic and discuss NMOC in Japan. Methods: We followed the progress of 403 women who underwent NMOC at our clinic between 2014 and 2021, totaling 592 reproductive cycles. Results: In total, 61 women underwent oocyte warming and fertility treatment. Of these, 13 women gave birth to 14 children. The median age at first oocyte cryopreservation was 38.3 years, and the oldest pregnant woman was 42 years. Most clients (60%) were in their late 30s. The median time between first oocyte cryopreservation and warming was 3.0 years. One woman was able to achieve a live birth with four vitrified oocytes. Conclusions: This is the first report in Japan documenting pregnancies and childbirths resulting from NMOC. Ideally, women hope to achieve natural pregnancy between 20 and 32 years of age. NMOC is an option for individuals who are unable to pursue pregnancy during optimal reproductive years and wish to preserve their fertility for future attempts. NMOC is recommended in cases with few indications, and it is necessary to continue accumulating data on its long-term safety and effectiveness.