Current Status of Maternal Gestational Weight Gain and Obstetric Outcomes in Japan

Introduction In 2021, the Japanese Ministry of Health, Labour and Welfare (JMHLW) revised the standard optimal gestational weight gain (GWG) to reduce the incidence of low-birth-weight infants (LBWI) in Japan. In this study, we examined whether maternal GWG increased and LBWI decreased after the revision. Materials and methods We reviewed the obstetric records of singleton pregnant Japanese women who delivered at our institute at ≥37 weeks’ gestation in 2020 (before revision) and 2022 (after revision). Results The maternal GWG was significantly increased after the revision of the JMHLW guideline; however, the expected decrease in the incidence of LBWI was not achieved. Conclusion The maternal GWG met the new criteria in the revised guidelines and did not appear to contribute to the reduced incidence of LBWI.