{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T05:26:52Z","timestamp":1775626012644,"version":"3.50.1"},"reference-count":37,"publisher":"SAGE Publications","issue":"2","license":[{"start":{"date-parts":[[2006,4,1]],"date-time":"2006-04-01T00:00:00Z","timestamp":1143849600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Stat Methods Med Res"],"published-print":{"date-parts":[[2006,4]]},"abstract":"<jats:p> Women tend to repeat reproductive outcomes, with past history of an adverse outcome being associated with an approximate two-fold increase in subsequent risk. These observations support the need for statistical designs and analyses that address this clustering. Failure to do so may mask effects, result in inaccurate variance estimators, produce biased or inefficient estimates of exposure effects. We review and evaluate basic analytic approaches for analysing reproductive outcomes, including ignoring reproductive history, treating it as a covariate or avoiding the clustering problem by analysing only one pregnancy per woman, and contrast these to more modern approaches such as generalized estimating equations with robust standard errors and mixed models with various correlation structures. We illustrate the issues by analysing a sample from the Collaborative Perinatal Project dataset, demonstrating how the statistical model impacts summary statistics and inferences when assessing etiologic determinants of birth weight. <\/jats:p>","DOI":"10.1191\/0962280206sm434oa","type":"journal-article","created":{"date-parts":[[2006,3,18]],"date-time":"2006-03-18T15:37:24Z","timestamp":1142696244000},"page":"103-126","source":"Crossref","is-referenced-by-count":55,"title":["Analysis of repeated pregnancy outcomes"],"prefix":"10.1177","volume":"15","author":[{"given":"Germaine Buck","family":"Louis","sequence":"first","affiliation":[{"name":"Epidemiology Branch Division of Epidemiology, Statistics and Prevention                         Research, National Institute of Child Health and Human Development,                         Rockville, MD, USA,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vanja","family":"Dukic","sequence":"additional","affiliation":[{"name":"Department of Health Studies, University of Chicago, 5841 S. Maryland                         Ave., MC 2007, Chicago, IL 60637, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Patrick J","family":"Heagerty","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, University of Washington, Box 357232,                         Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas A","family":"Louis","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, Bloomberg School of Public Health, Johns                         Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205-2179, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Courtney D","family":"Lynch","sequence":"additional","affiliation":[{"name":"Epidemiology Branch Division of Epidemiology, Statistics and Prevention                         Research, National Institute of Child Health and Human Development,                         Rockville, MD, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Louise M","family":"Ryan","sequence":"additional","affiliation":[{"name":"Department of Biostatistics, Harvard School of Public Health, Harvard                         University, 655 Huntington Ave., Boston, MA 02115-6009, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Enrique F","family":"Schisterman","sequence":"additional","affiliation":[{"name":"Epidemiology Branch Division of Epidemiology, Statistics and Prevention                         Research, National Institute of Child Health and Human Development,                         Rockville, MD, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ann","family":"Trumble","sequence":"additional","affiliation":[{"name":"Epidemiology Branch Division of Epidemiology, Statistics and Prevention                         Research, National Institute of Child Health and Human Development,                         Rockville, MD, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"name":"Pregnancy Modeling Working Group","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2006,4,1]]},"reference":[{"key":"atypb1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-1809.1949.tb02450.x"},{"key":"atypb2","doi-asserted-by":"publisher","DOI":"10.1097\/00003081-197003000-00008"},{"key":"atypb3","volume-title":"Preventing low birth weight","author":"Institute of Medicine","year":"1985"},{"key":"atypb4","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1985.tb03071.x"},{"key":"atypb5","doi-asserted-by":"publisher","DOI":"10.3109\/00016348309154207"},{"key":"atypb6","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/17.4.830"},{"key":"atypb7","doi-asserted-by":"publisher","DOI":"10.1016\/0895-4356(89)90115-7"},{"key":"atypb8","first-page":"485","volume":"84","author":"Raine T","year":"1994","journal-title":"Obsterics and Gynecology"},{"key":"atypb9","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-3016.11.s1.4.x"},{"key":"atypb10","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199407073310101"},{"key":"atypb11","doi-asserted-by":"publisher","DOI":"10.2105\/AJPH.72.3.253"},{"key":"atypb12","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-3016.11.s1.3.x"},{"key":"atypb13","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa031587"},{"key":"atypb14","doi-asserted-by":"crossref","first-page":"1448","DOI":"10.1093\/humrep\/12.7.1448","volume":"12","author":"Basso O","year":"1997","journal-title":"Human Reproduction"},{"key":"atypb15","first-page":"153","volume":"27","author":"Wall EM.","year":"1988","journal-title":"Journal of Family Practice"},{"key":"atypb16","volume-title":"Women and their pregnancies","author":"Niswander KR","year":"1972"},{"key":"atypb17","volume-title":"The first year of life","author":"Hardy JB","year":"1979"},{"key":"atypb18","volume-title":"A User\u2019s Guide to the Project and Data. 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