Assessment of embryologist sufficiency and associated regional disparities in Japanese assisted reproduction facilities using nationwide survey data (IZANAMI project)

Aims: This study aims to comprehensively examine the employment and practices of embryologists in Japan's assisted reproductive technology (ART) laboratories, focusing on the impact of various factors such as ART cycle numbers, add-ons, and regional differences. Additionally, it seeks to assess the extent to which Japanese ART facilities meet international minimum standards set by the American Society for Reproductive Medicine (ASRM). Methods: A survey was conducted from December 2021 to February 2022 among 621 ART facilities in Japan. The study categorized facilities into five ART cycle groups and compared the number of embryologists across these groups. It also examined the correlation between the number of embryologists, ART cycles, add-ons, and regional differences. Data were analyzed using linear regression and multiple linear regression analyses. Results: The study's findings revealed a significant correlation between the total number of embryologists at each facility and the ART cycles. Notably, there were significant differences in the number of embryologists across all ART cycle categories. Of the 435 facilities, only 44.6% met the ASRM minimum embryologist staffing requirement. The regression analysis further highlighted the significance of ART cycles and preimplantation genetic testing for aneuploidies as factors. Moreover, the number of embryologists stationed at urban facilities was significantly higher than at nonurban facilities, indicating a potential regional disparity. Conclusion: In Japan, it was first found that more than 50% of ART facilities do not have sufficient embryologists in place relative to the number of ART cycles. Furthermore, the add-ons and regional differences affect the placement of embryologists.