{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,25]],"date-time":"2026-01-25T13:27:51Z","timestamp":1769347671012,"version":"3.49.0"},"reference-count":19,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2024,6,29]],"date-time":"2024-06-29T00:00:00Z","timestamp":1719619200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council","doi-asserted-by":"publisher","award":["GNT1176437"],"award-info":[{"award-number":["GNT1176437"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council","doi-asserted-by":"publisher","award":["GNT2008793"],"award-info":[{"award-number":["GNT2008793"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council","doi-asserted-by":"publisher","award":["GNT2009765"],"award-info":[{"award-number":["GNT2009765"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Aust NZ J Obst Gynaeco"],"published-print":{"date-parts":[[2025,2]]},"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>During the COVID\u201019 pandemic, mitigation measures were associated with a reduction in preterm birth rates; while not clearly proven, this observation has sparked significant interest.<\/jats:p><\/jats:sec><jats:sec><jats:title>Aim<\/jats:title><jats:p>To understand the cause of this reduction by exploring the characteristics of preterm birth cohorts.<\/jats:p><\/jats:sec><jats:sec><jats:title>Material and methods<\/jats:title><jats:p>We performed a retrospective cohort study where we compared women who delivered preterm in three Melbourne maternity hospitals and conceived between November 2019 and February 2020 (mitigation measures\u2010exposed cohort) to women who delivered preterm and conceived between November 2018 and February 2019 (non\u2010exposed cohort). We compared maternal characteristics, pregnancy complications, antenatal interventions, intrapartum care, and indications for delivery.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>In the exposed cohort, 252\/3129 women delivered preterm (8.1%), vs 298\/3154 (9.4%) in the non\u2010exposed cohort (odds ratio (OR) 0.84, 95% CI 0.70\u20131.00, <jats:italic>P<\/jats:italic>\u2009=\u20090.051). The baseline characteristic of two cohorts were comparable. Rates of spontaneous preterm labour (sPTL) without preterm pre\u2010labour rupture of membranes (PPROM) were lower in the exposed cohort (13.1% vs 24.2%, OR 0.47, <jats:italic>P<\/jats:italic>\u2009=\u20090.001) while PPROM occurred more often (48.0% vs 35.6%, OR 1.67, <jats:italic>P<\/jats:italic>\u2009=\u20090.003). With a non\u2010statistically significant prolongation of pregnancy in the cohort exposed to mitigation measures for both sPTL without PPROM (35.4 vs 34.9\u2009weeks, <jats:italic>P<\/jats:italic>\u2009=\u20090.703) and PPROM (35.6 vs 34.9\u2009weeks, <jats:italic>P<\/jats:italic>\u2009=\u20090.184). The rate of spontaneous labour after PPROM was higher in the exposed cohort compared to the non\u2010exposed cohort (40.1% vs 24.1%, OR 2.09, <jats:italic>P<\/jats:italic>\u2009&lt;\u20090.001).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>The reduction in preterm delivery during mitigation measures may have been driven by a reduction in spontaneous labour without PPROM, which seemed to result in more PPROM later in pregnancy.<\/jats:p><\/jats:sec>","DOI":"10.1111\/ajo.13853","type":"journal-article","created":{"date-parts":[[2024,6,29]],"date-time":"2024-06-29T07:28:38Z","timestamp":1719646118000},"page":"114-120","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Characteristics of preterm births during <scp>COVID<\/scp>\u201019 mitigation measures"],"prefix":"10.1111","volume":"65","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-3142-9170","authenticated-orcid":false,"given":"Yizhen (Amy)","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology Monash University  Melbourne Victoria Australia"},{"name":"Women's and Newborn Program Monash Health  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexia","family":"Matheson","sequence":"additional","affiliation":[{"name":"Women's and Newborn Program Monash Health  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rochelle","family":"Sleaby","sequence":"additional","affiliation":[{"name":"Women's and Newborn Program Monash Health  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brendan","family":"Mulcahy","sequence":"additional","affiliation":[{"name":"Women's and Newborn Program Monash Health  Melbourne Victoria Australia"},{"name":"Department of Paediatrics Monash University  Melbourne Victoria 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Melbourne Victoria Australia"},{"name":"Aberdeen Centre for Women's Health Research, School of Medicine University of Aberdeen  Aberdeen UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9664-4182","authenticated-orcid":false,"given":"Atul","family":"Malhotra","sequence":"additional","affiliation":[{"name":"Women's and Newborn Program Monash Health  Melbourne Victoria Australia"},{"name":"Department of Paediatrics Monash University  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel L.","family":"Rolnik","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology Monash University  Melbourne Victoria Australia"},{"name":"Women's and Newborn Program Monash Health  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,6,29]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S2468-2667(20)30223-1"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1136\/archdischild-2020-319990"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2020.10.017"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajogmf.2020.100258"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmjgh-2021-006359"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1111\/ajo.13406"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12884-021-04249-8"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.23743"},{"key":"e_1_2_9_10_1","volume-title":"COVID\u201019: A chronology of state and territory government announcements","author":"Storen 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