{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T11:02:09Z","timestamp":1790766129096,"version":"4.1.0"},"reference-count":36,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":19,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"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":["Pregnancy"],"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To evaluate whether maternal nativity (US born vs. non\u2013US born) is associated with preterm birth (PTB) risk in individuals with twin pregnancies and to assess whether this association varies across racial and ethnic groups.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This cross\u2010sectional study used the National Center for Health Statistics and Centers for Disease Control and Prevention (CDC) natality dataset (2016\u20132023). This analysis included individuals aged 15\u201344 years with live\u2010born twins residing in the United States. Maternal nativity (US born vs. non\u2013US born) was stratified by race and ethnicity. Covariates included maternal age, education, insurance, prenatal care, smoking, prepregnancy body mass index, diabetes, hypertension, and year of birth. PTB (&lt;37\u00a0weeks) was further categorized as extremely (&lt;29\u00a0weeks), moderately (29\u201333weeks), and late (34\u201336\u00a0weeks). Binary and multinomial logistic regressions were used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Among 467,446 twin pregnancies, 282,754 (60.5%) were preterm. Of these, 191,972 (41.1%) were classified as late preterm (34 to &lt;37\u00a0weeks), 68,457 (14.6%) as moderately preterm (29 to &lt;34\u00a0weeks), and 22,325 (4.8%) as extremely preterm (&lt;29\u00a0weeks). Non\u2010US\u2010born individuals had lower odds of PTB compared to US\u2010born counterparts (aOR, 0.88; 95% CI, 0.86\u20130.89). The protective effect was strongest among non\u2010US\u2010born Black individuals (aOR, 0.65; 95% CI, 0.62\u20130.68). Across PTB subcategories, non\u2010US\u2010born individuals had reduced odds of extremely preterm (aOR, 0.85; 95% CI, 0.81\u20130.88), moderately preterm (aOR, 0.82; 95% CI, 0.80\u20130.84), and late PTB (aOR, 0.90; 95% CI, 0.88\u20130.92).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Non\u2010US\u2010born individuals had lower odds of PTB compared to US\u2010born individuals among twin pregnancies, extending prior findings from singleton populations to this high\u2010risk group. These findings reinforce the role of nativity as an important social determinant of perinatal health. Future work should examine the mechanisms underlying these disparities and the influence of structural and cultural factors on twin birth outcomes.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/pmf2.70361","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T13:24:25Z","timestamp":1784553865000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Maternal nativity and preterm birth disparities in twin pregnancies: A nationwide population\u2010based study"],"prefix":"10.1002","volume":"2","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5611-1231","authenticated-orcid":false,"given":"Hiba J.","family":"Mustafa","sequence":"first","affiliation":[{"name":"The Fetal Center at Riley Children's and Indiana University Health Division of Maternal\u2010Fetal Medicine Indiana University School of Medicine  Indianapolis Indiana USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-5762-6576","authenticated-orcid":false,"given":"Jana","family":"Karam","sequence":"additional","affiliation":[{"name":"Obstetrics and Gynecology Lebanese American University School of Medicine  Beirut Lebanon"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William A.","family":"Grobman","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology Brown University Medical School  Providence Rhode Island USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2332-1774","authenticated-orcid":false,"given":"Kevin L.","family":"Moss","sequence":"additional","affiliation":[{"name":"Department of Biostatistics and Health Data Science Indiana University School of Medicine  Indianapolis Indiana USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jasmine","family":"Johnson","sequence":"additional","affiliation":[{"name":"The Fetal Center at Riley Children's and Indiana University Health Division of Maternal\u2010Fetal Medicine Indiana University School of Medicine  Indianapolis Indiana USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4076-469X","authenticated-orcid":false,"given":"Maged M.","family":"Costantine","sequence":"additional","affiliation":[{"name":"Division of Maternal\u2010Fetal Medicine Department of Obstetrics and Gynecology The Ohio State University  Columbus Ohio USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heather A.","family":"Frey","sequence":"additional","affiliation":[{"name":"Division of Maternal\u2010Fetal Medicine Department of Obstetrics and Gynecology The Ohio State University  Columbus Ohio USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1966-9578","authenticated-orcid":false,"given":"Moti","family":"Gulersen","sequence":"additional","affiliation":[{"name":"Division of Maternal\u2010Fetal Medicine Thomas Jefferson University  Philadelphia Pennsylvania USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincenzo","family":"Berghella","sequence":"additional","affiliation":[{"name":"Division of Maternal\u2010Fetal Medicine Thomas Jefferson University  Philadelphia Pennsylvania USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alireza A.","family":"Shamshirsaz","sequence":"additional","affiliation":[{"name":"Comprehensive Fetal Care Center at Dell Children's Dell Children's Medical Center  Austin Texas USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"issue":"1","key":"e_1_2_8_2_1","first-page":"1","article-title":"Births: Final Data for 2021","volume":"72","author":"Osterman M. 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