Background This study investigates the changing regional disparities in obstetrician distribution across Japan over the past 20 years. As the impact of healthcare resource distribution on pregnancy loss outcomes (miscarriages and stillbirths) remains controversial, understanding this relationship is crucial for ensuring equitable perinatal care. Given Japan’s declining birthrate, ageing population and increasing urbanisation, we aim to clarify how the regional distribution of obstetricians has changed in relation to demand and its potential impact on pregnancy loss outcomes. Methods We conducted a regional correlation study using publicly available official statistical data. First, we calculated the number of obstetricians per birth within each secondary medical area (SMA) and calculated Gini coefficients to examine changes in the maldistribution of obstetricians over a 20-year period. Subsequently, the 335 SMAs in 2000 were clustered into four groups using a two-dimensional classification based on the median values of the number of obstetricians per birth (0.0079 obstetricians/birth) and population density (759.3/km 2 ) to identify which group they would have belonged to in 2020. Finally, multiple regression analysis was conducted. The objective variable was the 2020 ratio of pregnancy losses to live births, while explanatory variables included healthcare, demographic and socioeconomic factors. Pregnancy losses were calculated as the difference between 2019 notifications and 2020 live births. Results Based on Vital Statistics, while the total number of obstetricians nationwide was 11 688 at the baseline, the net increase over the 20-year period was only 629. Despite this overall increase, the Gini coefficient for the number of obstetricians per birth rose from 0.228 to 0.259, indicating that regional maldistribution has worsened relative to the number of births. The number of SMAs in the group with lower than the median number of obstetricians per birth in 2000 decreased from 167 to 57 in 2020; 7 SMAs moved from higher to lower number of obstetricians per birth groups. The number of births decreased by approximately two-thirds over 20 years, resulting in an increase in the number of obstetricians per birth of approximately 1.5 times. Multiple regression analysis showed that the number of obstetricians per birth and the number of childbirth facilities (total facilities and clinics alone) per woman aged 20–44 years were negatively associated with pregnancy loss, with only the number of facilities per woman aged 20–44 years showing a significant difference when the significance level was set at p <0.05. Conclusions Regional maldistribution of obstetricians in Japan has worsened over the past 20 years. Our findings suggest that clinical availability, rather than the absolute number of obstetricians per birth, may be more significantly associated with pregnancy loss outcomes. This underscores the critical importance of sustaining healthcare infrastructure, particularly through the strategic maintenance of clinics in rural areas. These results provide essential evidence for future healthcare planning and regional policy-making.
Kuriki et al. (Wed,) studied this question.