{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T10:53:11Z","timestamp":1792666391812,"version":"4.5.0"},"reference-count":35,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2022,10,3]],"date-time":"2022-10-03T00:00:00Z","timestamp":1664755200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["BJOG"],"published-print":{"date-parts":[[2023,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Objective<\/jats:title><jats:p>To describe the rates of and risk factors associated with iatrogenic and spontaneous preterm birth and the variation in rates between hospitals.<\/jats:p><\/jats:sec><jats:sec><jats:title>Design<\/jats:title><jats:p>Cohort study using electronic health records.<\/jats:p><\/jats:sec><jats:sec><jats:title>Setting<\/jats:title><jats:p>English National Health Service.<\/jats:p><\/jats:sec><jats:sec><jats:title>Population<\/jats:title><jats:p>Singleton births between 1 April 2015 and 31 March 2017.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Multivariable Poisson regression models were used to estimate adjusted risk ratios (adjRR) to measure association with maternal demographic and clinical risk factors.<\/jats:p><\/jats:sec><jats:sec><jats:title>Main outcome measures<\/jats:title><jats:p>Preterm births (&lt;37\u2009weeks of gestation) were defined as iatrogenic or spontaneous according to mode of onset of labour.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Of the births, 6.1% were preterm and of these, 52.8% were iatrogenic. The proportion of preterm births that were iatrogenic increased after 32\u2009weeks. Both sub\u2010groups were associated with previous preterm birth, extremes of maternal age, socio\u2010economic deprivation and smoking. Iatrogenic preterm birth was associated with higher body mass index (BMI) (BMI &gt;40\u2009kg\/m<jats:sup>2<\/jats:sup> adjRR 1.59, 95% CI 1.50\u20131.69) and previous caesarean (adjRR 1.88, 95% CI 1.83\u20131.95). Spontaneous preterm birth was less common in women with a higher BMI (BMI &gt;40\u2009kg\/m<jats:sup>2<\/jats:sup> adjRR 0.77, 95% CI 0.70\u20130.84) and in women with a previous caesarean (adjRR 0.87, 95% CI 0.83\u20130.90). More variation between NHS hospital trusts was observed in rates of iatrogenic, compared with spontaneous, preterm births.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Just over half of all preterm births resulted from iatrogenic intervention. Iatrogenic births have overlapping but different patterns of maternal demographic and clinical risk factors to spontaneous preterm births. Iatrogenic and spontaneous sub\u2010groups should therefore be measured and monitored separately, as well as in aggregate, to facilitate different prevention strategies. This is feasible using routinely acquired hospital data.<\/jats:p><\/jats:sec>","DOI":"10.1111\/1471-0528.17291","type":"journal-article","created":{"date-parts":[[2022,9,8]],"date-time":"2022-09-08T08:39:12Z","timestamp":1662626352000},"page":"33-41","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":33,"title":["Iatrogenic and spontaneous preterm birth in England: A population\u2010based cohort study"],"prefix":"10.1111","volume":"130","author":[{"given":"Harriet","family":"Aughey","sequence":"first","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"University Hospitals Bristol NHS Foundation Trust  Bristol UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9932-6865","authenticated-orcid":false,"given":"Jennifer","family":"Jardine","sequence":"additional","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"Department of Health Services Research and Policy London School of Hygiene and Tropical Medicine  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hannah","family":"Knight","sequence":"additional","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"Department of Health Services Research and Policy London School of Hygiene and Tropical Medicine  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6517-3485","authenticated-orcid":false,"given":"Ipek","family":"Gurol\u2010Urganci","sequence":"additional","affiliation":[{"name":"Department of Health Services Research and Policy London School of Hygiene and Tropical Medicine  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kate","family":"Walker","sequence":"additional","affiliation":[{"name":"Department of Health Services Research and Policy London School of Hygiene and Tropical Medicine  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tina","family":"Harris","sequence":"additional","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"Faculty of Health and Life Sciences De Montfort University  Leicester UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9451-2335","authenticated-orcid":false,"given":"Jan","family":"van der Meulen","sequence":"additional","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"Department of Health Services Research and Policy London School of Hygiene and Tropical Medicine  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jane","family":"Hawdon","sequence":"additional","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"Royal Free NHS Foundation Trust  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dharmintra","family":"Pasupathy","sequence":"additional","affiliation":[{"name":"Royal College of Obstetricians and Gynaecologists  London UK"},{"name":"Reproduction and Perinatal Centre, Faculty of Medicine and Health University of Sydney  Sydney New South Wales Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"name":"the NMPA Project Team","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2022,10,3]]},"reference":[{"key":"e_1_2_12_2_1","unstructured":"National Institute for Health and Care Excellence.Preterm labour and birth [Internet].2015[cited 2022 Jan 10]. 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