This study investigates the factors contributing to the decline in obstetrics and gynecology (OB/GYN) malpractice claims in Japan and highlights professional attitudes, institutional support systems, clinical practices, and policies that can further reduce such claims, while comparing these findings with malpractice data from the United States. We analyzed OB/GYN closed malpractice claims from the Supreme Court of Japan, along with data on maternal and neonatal mortality rates from the Ministry of Health, Labour and Welfare. We used Jonckheere-Terpstra tests to evaluate trends, considering p-values <
0.05 as statistically significant. In Japan, the proportion of medical malpractice claims in OB/GYN dropped significantly from 15.1% in 2004 to 5.2% in 2022 (p <
0.001). The number of claims per 100 OB/GYN physicians also significantly decreased from 0.9 in 2007 to 0.4 in 2016 (p <
0.001). Despite an increase in the cesarean delivery rate, both maternal and neonatal mortality rates have significantly decreased (p <
0.001 and p <
0.05, respectively). Japan's OB/GYN field saw a dramatic reduction in claims due to heightened awareness after a wrongful criminally charge, the establishment of financial compensation for cerebral palsy, standardized clinical guidelines, and adverse event investigation system.