{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,3]],"date-time":"2026-05-03T00:48:11Z","timestamp":1777769291588,"version":"3.51.4"},"reference-count":19,"publisher":"BMJ","issue":"2","license":[{"start":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T00:00:00Z","timestamp":1777420800000},"content-version":"unspecified","delay-in-days":28,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["bmjph"],"accepted":{"date-parts":[[2026,3,12]]},"published-print":{"date-parts":[[2026,4]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>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\u2019s 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.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      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\n                      <jats:sup>2<\/jats:sup>\n                      ) 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.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      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\u201344 years were negatively associated with pregnancy loss, with only the number of facilities per woman aged 20\u201344 years showing a significant difference when the significance level was set at\n                      <jats:italic>p<\/jats:italic>\n                      &lt;0.05.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>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.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjph-2025-002636","type":"journal-article","created":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T16:15:14Z","timestamp":1777479314000},"page":"e002636","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Regional correlation study of obstetrician maldistribution and its impact on pregnancy loss outcomes in Japan amid declining fertility"],"prefix":"10.1136","volume":"4","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0895-0815","authenticated-orcid":false,"given":"Ken","family":"Kuriki","sequence":"first","affiliation":[{"name":"Graduate School of Public Health, Shizuoka Graduate University of Public Health, Shizuoka, Japan"},{"name":"Yaizu City Hospital, Yaizu, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4876-446X","authenticated-orcid":false,"given":"Eiji","family":"Nakatani","sequence":"additional","affiliation":[{"name":"Graduate School of Public Health, Shizuoka Graduate University of Public Health, Shizuoka, Japan"},{"name":"Department of Biostatistics and Health Data Science, Graduate School of Medical Sciences Nagoya City University, Nagoya, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4767-331X","authenticated-orcid":false,"given":"Yasuto","family":"Sato","sequence":"additional","affiliation":[{"name":"Graduate School of Public Health, Shizuoka Graduate University of Public Health, Shizuoka, Japan"},{"name":"Center for Health Informatics Policy, National Institute of Public Health, Saitama, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2026,4,29]]},"reference":[{"key":"2026042909150709000_4.2.e002636.1","first-page":"366","article-title":"Recent trends in regional population: Continuing Population concentration in metropolitan areas","volume":"271","author":"Obayashi","year":"2019","journal-title":"J Clin Exp Med"},{"key":"2026042909150709000_4.2.e002636.2","doi-asserted-by":"crossref","DOI":"10.1002\/psp.2786","article-title":"Moving up and down the urban hierarchy: Age\u2010specific internal migration patterns in Japan based on the 2020 census","volume":"30","author":"Kotsubo","year":"2024","journal-title":"Popul Space Place"},{"key":"2026042909150709000_4.2.e002636.3","unstructured":"Ministry of Education C, Sports, Science and Technology . Regarding the increase in medical school admission quotas for the 2025 academic year (Reiwa 7). Presented at: 184th Meeting of the University Sub-division of the Central Council for Education. [in Japanese], 2024. Available: https:\/\/www.mext.go.jp\/b_menu\/shingi\/chukyo\/chukyo4\/siryo\/mext_01834.html [Accessed 13 Feb 2026]."},{"key":"2026042909150709000_4.2.e002636.4","article-title":"Transition of physician distribution (1980-2002) in Japan and factors predicting future rural practice","volume":"9","author":"Inoue","year":"2009","journal-title":"Rural Remote Health"},{"key":"2026042909150709000_4.2.e002636.5","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2017-018538","article-title":"Examining changes in the equity of physician distribution in Japan: a specialty-specific longitudinal study","volume":"8","author":"Hara","year":"2018","journal-title":"BMJ Open"},{"key":"2026042909150709000_4.2.e002636.6","unstructured":"Ministry of Health LaW . Guidelines for Developing a Plan for Securing Physicians [in Japanese], 2019. Available: https:\/\/www.mhlw.go.jp\/content\/000700134.pdf [Accessed 13 Feb 2026]."},{"key":"2026042909150709000_4.2.e002636.7","doi-asserted-by":"crossref","DOI":"10.1186\/1475-9276-8-5","article-title":"Trend in geographic distribution of physicians in Japan","volume":"8","author":"Toyabe","year":"2009","journal-title":"Int J Equity Health"},{"key":"2026042909150709000_4.2.e002636.8","doi-asserted-by":"publisher","DOI":"10.1016\/j.healthpol.2010.02.008"},{"key":"2026042909150709000_4.2.e002636.9","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2016-013922","article-title":"Examining sufficiency and equity in the geographic distribution of physicians in Japan: a longitudinal study","volume":"7","author":"Hara","year":"2017","journal-title":"BMJ Open"},{"key":"2026042909150709000_4.2.e002636.10","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0245385","article-title":"The geographical maldistribution of obstetricians and gynecologists in Japan","volume":"16","author":"Matsumoto","year":"2021","journal-title":"PLoS One"},{"key":"2026042909150709000_4.2.e002636.11","doi-asserted-by":"crossref","DOI":"10.1186\/1478-4491-11-59","article-title":"Widening disparity in the geographic distribution of pediatricians in Japan","volume":"11","author":"Sasaki","year":"2013","journal-title":"Hum Resour Health"},{"key":"2026042909150709000_4.2.e002636.12","doi-asserted-by":"crossref","DOI":"10.1186\/s12913-023-10258-4","article-title":"Gender difference of geographic distribution of physicians in Japan: three-point analysis of 1994, 2004 and 2014","volume":"23","author":"Kimura","year":"2023","journal-title":"BMC Health Serv Res"},{"key":"2026042909150709000_4.2.e002636.13","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2019-031882","article-title":"How far is too far? A nationwide cross-sectional study for establishing optimal hospital access time for Korean pregnant women","volume":"9","author":"Kwak","year":"2019","journal-title":"BMJ Open"},{"key":"2026042909150709000_4.2.e002636.14","article-title":"Kansas maternity deserts: a cross-sectional study of rural obstetric providers","volume":"21","author":"Taporco","year":"2021","journal-title":"Rural Remote Health"},{"key":"2026042909150709000_4.2.e002636.15","doi-asserted-by":"crossref","DOI":"10.1186\/s12884-024-06535-7","article-title":"Navigating geographical disparities: access to obstetric hospitals in maternity care deserts and across the United States","volume":"24","author":"Fontenot","year":"2024","journal-title":"BMC Pregnancy Childbirth"},{"key":"2026042909150709000_4.2.e002636.16","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2020-036852","article-title":"Impact of obstetric unit closures, travel time and distance to obstetric services on maternal and neonatal outcomes in high-income countries: a systematic review","volume":"10","author":"Malouf","year":"2020","journal-title":"BMJ Open"},{"key":"2026042909150709000_4.2.e002636.17","doi-asserted-by":"crossref","DOI":"10.1186\/s12913-018-3441-y","article-title":"Board certification and urban-rural migration of physicians in Japan","volume":"18","author":"Koike","year":"2018","journal-title":"BMC Health Serv Res"},{"key":"2026042909150709000_4.2.e002636.18","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.puhe.2018.02.005","article-title":"Trend in unequal geographical distribution of doctors by age and sex in Japan from 2004 to 2014","volume":"159","author":"Morita","year":"2018","journal-title":"Public Health (Fairfax)"},{"key":"2026042909150709000_4.2.e002636.19","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2018-023696","article-title":"Future projection of the physician workforce and its geographical equity in Japan: a cohort-component model","volume":"8","author":"Hara","year":"2018","journal-title":"BMJ Open"}],"container-title":["BMJ Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjph-2025-002636","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T16:15:19Z","timestamp":1777479319000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjpublichealth.bmj.com\/lookup\/doi\/10.1136\/bmjph-2025-002636"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4]]},"references-count":19,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,4,29]]},"published-print":{"date-parts":[[2026,4]]}},"alternative-id":["10.1136\/bmjph-2025-002636"],"URL":"https:\/\/doi.org\/10.1136\/bmjph-2025-002636","relation":{},"ISSN":["2753-4294"],"issn-type":[{"value":"2753-4294","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4]]}}}