{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T03:02:48Z","timestamp":1787022168715,"version":"build-2736575974"},"reference-count":34,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2025,9,8]],"date-time":"2025-09-08T00:00:00Z","timestamp":1757289600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00c3fico e Tecnol\u00c3\u00b3gico","doi-asserted-by":"publisher","award":["443775\/2018"],"award-info":[{"award-number":["443775\/2018"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","award":["OPP1201939"],"award-info":[{"award-number":["OPP1201939"]}],"id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00c3fico e Tecnol\u00c3\u00b3gico","doi-asserted-by":"publisher","award":["Bolsista de Desenvolvimento Tecnol\u00f3gico Industrial N\u00edvel B"],"award-info":[{"award-number":["Bolsista de Desenvolvimento Tecnol\u00f3gico Industrial N\u00edvel B"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00c3fico e Tecnol\u00c3\u00b3gico","doi-asserted-by":"publisher","award":["Bolsista de Desenvolvimento Tecnol\u00f3gico Industrial N\u00edvel B"],"award-info":[{"award-number":["Bolsista de Desenvolvimento Tecnol\u00f3gico Industrial N\u00edvel B"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00c3fico e Tecnol\u00c3\u00b3gico","doi-asserted-by":"publisher","award":["Produtividade em Pesquisa 2"],"award-info":[{"award-number":["Produtividade em Pesquisa 2"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Studies have shown that excessive obstetric interventions such as induced labor and caesarean sections have contributed to the shortening of the length of gestation, leading to a left shift in gestational age (GA) at birth. The aim of this study was to analyze trends in GA and the contribution of associated factors to changes in S\u00e3o Paulo city, Brazil during the period 2012\u20132019. We conducted an observational time-series study of births in S\u00e3o Paulo using data from Brazil\u2019s national live births information system (SINASC). We calculated the annual percent change (APC) of births by GA between 2012 and 2019 and between the first and second four-year periods of the time series by applying log transformation to the percentages, followed by Prais-Winsten regression. A total of 1,525,759 live births were analyzed. From 2015, there was an increase in the proportion of live births between 39 and 40 weeks from 2015 and a fall in the proportion of early term (37\u201338 weeks) and preterm (&lt; 37 weeks) births throughout the study period. The APC of births at 39 and 40 weeks was 7.9% and 5.7%, respectively, while the proportion of births at other gestational ages showed a statistically significant reduction over the study period. These reductions were more pronounced in the first four-year period (2012\u20132015). The same trend was observed when the data were analyzed by type of delivery, type of service (public or private), maternal age, and maternal education level. The findings show that there was a right shift in the GA curve during the study period and a reduction in the proportion of preterm and early term births. These changes were more pronounced in births that occurred in private hospitals. These changes reflect public policies implemented to reduce obstetric interventions such as induced labor and caesarean section before labor, especially before 39 weeks of gestation.<\/jats:p>","DOI":"10.1371\/journal.pone.0319307","type":"journal-article","created":{"date-parts":[[2025,9,8]],"date-time":"2025-09-08T17:45:10Z","timestamp":1757353510000},"page":"e0319307","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Trends in gestational age at birth in the city of S\u00e3o Paulo, Brazil between 2012 and 2019"],"prefix":"10.1371","volume":"20","author":[{"given":"Margarida Maria Ten\u00f3rio de Azevedo","family":"Lira","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marina","family":"de Freitas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eliana de Aquino","family":"Bonilha","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C\u00e9lia Maria Castex","family":"Aly","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patr\u00edcia Carla","family":"dos Santos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0140-2063","authenticated-orcid":true,"given":"Denise Yoshie","family":"Niy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carmen Simone Grilo","family":"Diniz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,9,8]]},"reference":[{"issue":"1","key":"pone.0319307.ref001","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1053\/j.semperi.2006.01.009","article-title":"Changes in the gestational age distribution among U.S. singleton births: impact on rates of late preterm birth, 1992 to 2002","volume":"30","author":"MJ Davidoff","year":"2006","journal-title":"Semin Perinatol"},{"key":"pone.0319307.ref002","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/j.clp.2011.06.009","article-title":"Morbidity and mortality in late preterm and early term newborns: A continuum","volume":"38","author":"WA Engle","year":"2011","journal-title":"Clin Perinatol"},{"issue":"23","key":"pone.0319307.ref003","doi-asserted-by":"crossref","first-page":"2445","DOI":"10.1001\/jama.2013.6235","article-title":"Defining \u201cterm\u201d pregnancy: recommendations from the Defining \u201cTerm\u201d Pregnancy Workgroup","volume":"309","author":"CY Spong","year":"2013","journal-title":"JAMA"},{"issue":"12","key":"pone.0319307.ref004","article-title":"Trends in All-Cause Mortality across Gestational Age in Days for Children Born at Term","volume":"10","author":"CS Wu","year":"2015","journal-title":"PLoS One"},{"issue":"1","key":"pone.0319307.ref005","doi-asserted-by":"crossref","first-page":"33","DOI":"10.7322\/jhgd.113712","article-title":"Why do women in the private sector have shorter pregnancies in Brazil? Left shift of gestational age, caesarean section and inversion of the expected disparity","volume":"26","author":"CSG Diniz","year":"2016","journal-title":"J Hum Growth Dev"},{"issue":"12","key":"pone.0319307.ref006","article-title":"Burden of early-term birth on adverse infant outcomes: a population-based cohort study in Brazil","volume":"7","author":"C Leal M do","year":"2017","journal-title":"BMJ Open"},{"issue":"2","key":"pone.0319307.ref007","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0056238","article-title":"Trends in the distribution of gestational age and contribution of planned births in New South Wales, Australia","volume":"8","author":"N Nassar","year":"2013","journal-title":"PLoS One"},{"key":"pone.0319307.ref008","article-title":"Committee Opinion: Definition of Term Pregnancy","author":"ACOG","year":"2013","journal-title":"Obstet Gynecol"},{"issue":"5","key":"pone.0319307.ref009","doi-asserted-by":"crossref","first-page":"1483","DOI":"10.1590\/S1413-81232013000500034","article-title":"SIM e SINASC: representa\u00e7\u00e3o social de enfermeiros e profissionais de setores administrativos que atuam em hospitais no munic\u00edpio de S\u00e3o Paulo","volume":"18","author":"D Schoeps","year":"2013","journal-title":"Ci\u00eanc sa\u00fade coletiva"},{"issue":"1","key":"pone.0319307.ref010","article-title":"Coverage, completeness and reliability of the data in the Information System on Live Births in public maternity wards in the municipality in S\u00e3o Paulo, Brazil, 2011","volume":"27","author":"A Bonilha E de","year":"2018","journal-title":"Epidemiol Serv Saude"},{"key":"pone.0319307.ref011","article-title":"Anomalias cong\u00eanitas no sistema de informa\u00e7\u00f5es sobre nascidos vivos, 2001-2020: relato de experi\u00eancia da gest\u00e3o do sistema no munic\u00edpio de S\u00e3o Paulo","volume-title":"Sa\u00fade Brasil 2020\/2021: anomalias cong\u00eanitas priorit\u00e1rias para a vigil\u00e2ncia ao nascimento","author":"ESR Vico","year":"2021"},{"issue":"8","key":"pone.0319307.ref012","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2019.10236","article-title":"Association of Cesarean Delivery With Risk of Neurodevelopmental and Psychiatric Disorders in the Offspring: A Systematic Review and Meta-analysis","volume":"2","author":"T Zhang","year":"2019","journal-title":"JAMA Netw Open"},{"issue":"2","key":"pone.0319307.ref013","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1111\/ajo.13253","article-title":"Naegele\u2019s rule and the length of pregnancy - 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