{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T16:25:29Z","timestamp":1791822329332,"version":"4.3.4"},"reference-count":32,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T00:00:00Z","timestamp":1771286400000},"content-version":"vor","delay-in-days":16,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T00:00:00Z","timestamp":1769904000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Health Science Reports"],"published-print":{"date-parts":[[2026,2]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background and Aims<\/jats:title>\n                    <jats:p>To analyze the distribution pattern of maternal age and the impact of different maternal age subgroups on pregnancy adverse outcomes in China.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      This is a multicenter retrospective cohort study from 2010 to 2017. Live\u2010born singletons were included. The pregnancy and perinatal adverse outcomes were collected. The \u03c7\n                      <jats:sup>2<\/jats:sup>\n                      test was used to compare the frequencies among categorical data, Student's\n                      <jats:italic>t<\/jats:italic>\n                      \u2010test, or Kruskal\u2013Wallis\n                      <jats:italic>H<\/jats:italic>\n                      \u2010test for continuous variables. Each adverse outcome (\n                      <jats:italic>p<\/jats:italic>\n                      \u2010value\u2009&lt;\u20090.2 in univariate analysis) was entered into a multinomial multivariate logistic regression to compare maternal age subgroups (&lt;\u200920 years, 21\u201324 years, 30\u201334 years, and \u2265\u200935 years) with the 25\u201329 years group, adjusting for parity.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      There were 216,404 mothers with a mean age of 27.4\u2009\u00b1\u20094.9 years. The proportion of mothers of &lt;\u200920 years, 21\u201324 years, 25\u201329 years, 30\u201334 years, and \u2265\u200935 years was 2.5%, 26.0%, 42.5%, 20.1%, and 9.0%, respectively. Mean gestational age at delivery and birthweight were inverted\n                      <jats:italic>U<\/jats:italic>\n                      \u2010shaped associated with the maternal age. The incidence of preterm delivery was high in the maternal age &lt;\u200920 years (11.4%) and \u2265\u200935 years (10.7%) categories. Compared with maternal age 25\u201329 years, age &lt;\u200920 years and age 20\u201324 years were associated with preterm delivery, low birthweight infants, very low birthweight infants, Apgar score \u2264\u20095 at 5\u2009min, and eclampsia. Maternal age \u2265\u200935 years and age 30\u201334 years were associated with the elevated risk of preterm delivery, macrosomia, low birthweight infants, very\u2010low\u2010birthweight infant delivery, gestational diabetes mellitus, gestational hypertension, pre\u2010eclampsia, eclampsia, placenta previa, elective and emergency cesarean delivery. Maternal age \u2265\u200935 years was associated with a high risk of Apgar score \u2264\u20095 at 5\u2009min. The overall incidence of cesarean delivery was 41.7% (56.7% in age \u2265\u200935 years).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This large cohort study demonstrated a significant impact of maternal age on pregnancy adverse outcomes in China, with the &lt;\u200920 years, 20\u201324 years, 30\u201334 years, and \u2265\u200935 years age groups being associated with an enhanced risk compared with the 25\u201329 years age group. The high cesarean delivery rate was alarming.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/hsr2.71817","type":"journal-article","created":{"date-parts":[[2026,2,18]],"date-time":"2026-02-18T07:37:57Z","timestamp":1771400277000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Impact of Different Maternal Age Subgroups on Pregnancy Adverse Outcomes in China: A Multicenter Cohort Study"],"prefix":"10.1002","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8016-0826","authenticated-orcid":false,"given":"Yi\u2010Jie","family":"Zhang","sequence":"first","affiliation":[{"name":"Department of Neonatology The Affiliated Hospital of Qingdao University Qingdao China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianguo","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Neonatology Children's Hospital of Fudan University Shanghai China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Neonatology Children's Hospital of Fudan University Shanghai China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,2,17]]},"reference":[{"key":"e_1_2_12_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(23)00878-4"},{"key":"e_1_2_12_3_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12887-022-03579-6"},{"key":"e_1_2_12_4_1","doi-asserted-by":"publisher","DOI":"10.1002\/ijgo.13195"},{"key":"e_1_2_12_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bpobgyn.2020.07.005"},{"key":"e_1_2_12_6_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0000000000004873"},{"key":"e_1_2_12_7_1","first-page":"1","article-title":"Births: Final Data for 2022","volume":"73","author":"Osterman M. 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