{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T09:16:01Z","timestamp":1775466961043,"version":"3.50.1"},"reference-count":34,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T00:00:00Z","timestamp":1769385600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T00:00:00Z","timestamp":1769385600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["BJOG"],"published-print":{"date-parts":[[2026,5]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>Evaluate the rate and trend of preterm birth (PTB) and the associated perinatal survival in Hong Kong.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Population\u2010based, repeated cross\u2010sectional time series.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>All public maternity hospitals.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Population<\/jats:title>\n                    <jats:p>845\u2009640 singleton and 26\u2009748 twin deliveries from 2000 to 2023.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Two analyses were performed (i) spontaneous PTB (sPTB) vs. iatrogenic PTB (iPTB), (ii) spontaneous PTB with no preterm prelabour rupture of membranes (PPROM) (sPTB\u2010noPPROM) versus. PTB following PPROM (PTB\u2010PPROM) vs. iPTB.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Main Outcome Measures<\/jats:title>\n                    <jats:p>PTB rate and perinatal survival.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Simply dividing PTB into sPTB and iPTB demonstrated increasing PTB rates for both types amongst singleton and twin pregnancy. Subclassification of sPTB into sPTB\u2010noPPROM and PTB\u2010PPROM demonstrated a downward trend in sPTB\u2010noPPROM while PTB\u2010PPROM increased significantly (singleton: sPTB\u2010noPPROM average annual percent change (AAPC) \u22120.96, 95% CI \u22121.67 to \u22120.41; PTB\u2010PPROM AAPC 3.4, 95% CI 2.89 to 4.18; iPTB AAPC 2.01, 95% CI 1.57 to 2.45; twin: sPTB\u2010noPPROM AAPC \u22122.62, 95% CI \u22124.09 to \u22121.58; PTB\u2010PPROM AAPC 3.05, 95% CI 2.46 to 3.72; iPTB AAPC 2.75, 95% CI 1.82 to 3.69). PTB\u2010PPROM and iPTB were the leading causes of PTB for singleton and twin pregnancy, respectively. Hypertensive disorders were the predominant causes of iPTB for both singleton and twin pregnancy while iPTB indicated by maternal illnesses reduced over time. Reduction of neonatal mortality rates were noted amongst iPTB for singleton &lt;\u200937\u2009weeks and twin pregnancies at 34\n                      <jats:sup>+0<\/jats:sup>\n                      \u201336\n                      <jats:sup>+6<\/jats:sup>\n                      weeks. The rate of stillbirth and perinatal mortality also reduced amongst PTB of twin pregnancies.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Perinatal survival improved despite increasing PTB rates. The trend of PTB should be interpreted in the context of perinatal health indicators, and categorisation of PTB could aid with truly reflecting and explaining the trends and patterns of PTB within a population.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/1471-0528.70166","type":"journal-article","created":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T11:17:22Z","timestamp":1769512642000},"page":"1213-1226","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Temporal Patterns in Preterm Birth Subtypes and Perinatal Survival, 2000\u20132023: Population\u2010Based, Repeated Cross\u2010Sectional Time\u2010Series"],"prefix":"10.1111","volume":"133","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1207-6494","authenticated-orcid":false,"given":"Ka Wang","family":"Cheung","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology Queen Mary Hospital, The University of Hong Kong  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