Assisted reproductive technology in Japan: A summary report for 2018 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology

Purpose: Since 2007, the Japan Society of Obstetrics and Gynecology (JSOG) has collected cycle-based data for assisted reproductive technology (ART) in an online registry. Here, we present the characteristics and treatment outcomes of ART cycles registered during 2018. Methods: The Japanese ART registry consists of cycle-specific information for all ART treatment cycles implemented at 621 participating facilities. We conducted descriptive analyses for such cycles registered for 2018. Results: In total, 454 893 treatment cycles and 56 979 neonates were reported in 2018: both increased from 2017. The mean maternal age was 38.0 years (standard deviation ± 4.7). Of 247 402 oocyte retrievals, 118 378 (47.8%) involved freeze-all-embryos cycles; fresh embryo transfer (ET) was performed in 50 463 cycles: a decreasing trend since 2015. A total of 199 914 frozen-thawed ET cycles were reported, resulting in 69 357 pregnancies and 49 360 neonates born. Single ET (SET) was performed in 82.2% of fresh transfers and 83.4% of frozen-thawed cycles, with singleton pregnancy/live birth rates of 97.2%/97.2% and 97.0%/97.2%, respectively. Conclusions: Total ART cycles and subsequent live births increased in 2018. SET was performed in over 80% of cases, and the mode of ET has shifted continuously from using fresh embryos to frozen-thawed ones compared with previous years.