{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T08:13:07Z","timestamp":1790669587293,"version":"4.1.0"},"reference-count":35,"publisher":"BMJ","issue":"11","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2014,9,24]]},"published-print":{"date-parts":[[2014,11]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To evaluate the associations between maternal age and obstetric and neonatal outcomes in primiparous women with emphasis on teenagers and older women.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>A population-based cohort study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>The Swedish Medical Birth Register.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>Primiparous women with singleton births from 1992 through 2010 (N=798\u2005674) were divided into seven age groups: &lt;17\u2005years, 17\u201319\u2005years and an additional five 5-year classes. The reference group consisted of the women aged 25\u201329\u2005years.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary outcome<\/jats:title>\n                    <jats:p>Obstetric and neonatal outcome.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The teenager groups had significantly more vaginal births (adjusted OR (aOR) 2.04 (1.79 to 2.32) and 1.95 (1.88 to 2.02) for age &lt;17\u2005years and 17\u201319\u2005years, respectively); fewer caesarean sections (aOR 0.57 (0.48 to 0.67) and 0.55 (0.53 to 0.58)), and instrumental vaginal births (aOR 0.43 (0.36 to 0.52) and 0.50 (0.48 to 0.53)) compared with the reference group. The opposite was found among older women reaching a fourfold increased OR for caesarean section. The teenagers showed no increased risk of adverse neonatal outcome but presented an increased risk of prematurity &lt;32\u2005weeks (aOR 1.66 (1.10 to 2.51) and 1.20 (1.04 to 1.38)). Women with advancing age (\u226530\u2005years) revealed significantly increased risk of prematurity, perineal lacerations, preeclampsia, abruption, placenta previa, postpartum haemorrhage and unfavourable neonatal outcomes compared with the reference group.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>For clinicians counselling young women it is of importance to highlight the obstetrically positive consequences that fewer maternal complications and favourable neonatal outcomes are expected. The results imply that there is a need for individualising antenatal surveillance programmes and obstetric care based on age grouping in order to attempt to improve the outcomes in the age groups with less favourable obstetric and neonatal outcomes. Such changes in surveillance programmes and obstetric interventions need to be evaluated in further studies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2014-005840","type":"journal-article","created":{"date-parts":[[2014,11,12]],"date-time":"2014-11-12T00:18:19Z","timestamp":1415751499000},"page":"e005840","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":108,"title":["Impact of maternal age on obstetric and neonatal outcome with emphasis on primiparous adolescents and older women: a Swedish Medical Birth Register Study"],"prefix":"10.1136","volume":"4","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4679-550X","authenticated-orcid":false,"given":"Marie","family":"Blomberg","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Link\u00f6ping University, Link\u00f6ping, 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The Swedish Medical Birth Register: a summary of content and quality. Research Report, Article no: 2003-112-3. Centre for Epidemiology, National Board of Health and Welfare Stockholm, 2003. http:\/\/www.socialstyrelsen.se\/publikationer2003\/2003-112-3 (accessed May 2014)."},{"key":"2025121602304259000_4.11.e005840.23","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1177\/140349489001800209","article-title":"A quality study of a medical birth registry","volume":"18","author":"Cnattingius","year":"1990","journal-title":"Scand J Soc Med"},{"key":"2025121602304259000_4.11.e005840.24","doi-asserted-by":"publisher","DOI":"10.1034\/j.1600-0412.2003.00172.x"},{"key":"2025121602304259000_4.11.e005840.25","doi-asserted-by":"publisher","DOI":"10.1007\/BF01719316"},{"key":"2025121602304259000_4.11.e005840.26","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000107291.46159.00"},{"key":"2025121602304259000_4.11.e005840.27","doi-asserted-by":"publisher","DOI":"10.1093\/eurpub\/11.3.329"},{"key":"2025121602304259000_4.11.e005840.28","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1186\/1471-2393-14-321","article-title":"Varying gestational age patterns in cesarean delivery: an international comparison","volume":"14","author":"Delnord","year":"2014","journal-title":"BMC Pregnancy Childbirth"},{"issue":"(Suppl 1)","key":"2025121602304259000_4.11.e005840.29","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1111\/1471-0528.12631","article-title":"Risk factors for spontaneous and provider-initiated preterm delivery in high and low Human Development Index countries: a secondary analysis of the World Health Organization Multicountry Survey on Maternal and Newborn Health","volume":"121","author":"Morisaki","year":"2014","journal-title":"BJOG"},{"key":"2025121602304259000_4.11.e005840.30","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1016\/j.jpag.2011.02.008","article-title":"Is young maternal age really a risk factor for adverse pregnancy outcome in a Canadian tertiary referral hospital","volume":"24","author":"Shrim","year":"2011","journal-title":"J Pediatr Adolesc Gynecol"},{"key":"2025121602304259000_4.11.e005840.31","doi-asserted-by":"crossref","first-page":"253","DOI":"10.3109\/01443611003605294","article-title":"Obstetric outcome of teenage pregnancies from 2002 to 2008: the Sheffield experience","volume":"30","author":"Jivraj","year":"2010","journal-title":"J Obstet Gynaecol"},{"key":"2025121602304259000_4.11.e005840.32","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1007\/s00404-010-1679-7","article-title":"Teenage deliveries in Northern Germany: always a risk factor for higher surgical delivery rates","volume":"284","author":"Beyer","year":"2011","journal-title":"Arch Gynecol Obstet"},{"key":"2025121602304259000_4.11.e005840.33","doi-asserted-by":"publisher","DOI":"10.1016\/S0029-7844(00)01075-9"},{"key":"2025121602304259000_4.11.e005840.34","doi-asserted-by":"publisher","DOI":"10.1093\/humupd\/dms043"},{"key":"2025121602304259000_4.11.e005840.35","doi-asserted-by":"publisher","DOI":"10.1007\/s11906-006-0045-4"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2014-005840","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,16]],"date-time":"2025-12-16T10:30:52Z","timestamp":1765881052000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2014-005840"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,11]]},"references-count":35,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2014,11,11]]},"published-print":{"date-parts":[[2014,11]]}},"alternative-id":["10.1136\/bmjopen-2014-005840"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2014-005840","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,11]]}}}