{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T06:08:40Z","timestamp":1789884520987,"version":"4.0.1"},"reference-count":48,"publisher":"BMJ","issue":"1","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2016,12,15]]},"published-print":{"date-parts":[[2017,1]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Socioeconomic inequalities in birth weight and in body mass index (BMI) later in childhood are in opposite directions, which raises questions about when during childhood the change in direction happens. We examined how maternal and paternal education and household income were associated with birthweight z-scores and with BMI z-scores at age 5 and 12\u2005months and 7\u2005years, and we examined the socioeconomic differences in the tracking of these z-scores across infancy and childhood.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      The associations were studied in a cohort of children in the Danish National Birth Cohort, single born between 1997 and 2003, for whom information on body size from at least 1 of 4 time points (n=85\u2005062) was recorded\n                      <jats:italic>.<\/jats:italic>\n                      We examined the associations using linear mixed-effects modelling.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Children from families with a low maternal and paternal educational level changed their body size z-scores upwards between birth and age 7\u2005years. At age 5 and 12\u2005months, there were no educational gradient. A low maternal educational level was associated with lower birth weight for gestational age z-scores at birth for boys (\u22120.199; 95% CI \u22120.230 to \u22120.169) and girls (\u22120.198; 95% CI \u22120.229 to \u22120.167) and higher BMI z-scores at age 7 for boys (0.198; 95% CI 0.154 to 0.242) and girls (0.218; 95% CI 0.173 to 0.264). There was not a similarly clear pattern in the tracking between different household income groups. However, a low household income level was associated with higher z-scores of both birth weight and BMI at age 7\u2005years, but with a much weaker gradient at 5 and 12\u2005months.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>The educational gradient shifts from positive with birth weight, to none during infancy to inverse with BMI at age 7\u2005years. In contrast, the income gradient was positive at birth and at 7\u2005years and much weaker during infancy.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2016-011781","type":"journal-article","created":{"date-parts":[[2017,1,21]],"date-time":"2017-01-21T20:10:23Z","timestamp":1485029423000},"page":"e011781","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":39,"title":["Socioeconomic disparities in birth weight and body mass index during infancy through age 7\u2005years: a study within the Danish National Birth Cohort"],"prefix":"10.1136","volume":"7","author":[{"given":"Camilla Schmidt","family":"Morgen","sequence":"first","affiliation":[{"name":"Department of Clinical Epidemiology (formerly Institute of Preventive Medicine), Copenhagen, Denmark"},{"name":"Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4296-8488","authenticated-orcid":false,"given":"Per Kragh","family":"Andersen","sequence":"additional","affiliation":[{"name":"Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laust Hvas","family":"Mortensen","sequence":"additional","affiliation":[{"name":"Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura D","family":"Howe","sequence":"additional","affiliation":[{"name":"MRC Integrative Epidemiology Unit, The University of Bristol, and School of Social and Community Medicine, University of Bristol, Bristol, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mette","family":"Rasmussen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pernille","family":"Due","sequence":"additional","affiliation":[{"name":"National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thorkild I A","family":"S\u00f8rensen","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology (formerly Institute of Preventive Medicine), Copenhagen, Denmark"},{"name":"MRC Integrative Epidemiology Unit, The University of Bristol, and School of Social and Community Medicine, University of Bristol, Bristol, UK"},{"name":"Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Public Health, University of Copenhagen, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne-Marie Nybo","family":"Andersen","sequence":"additional","affiliation":[{"name":"Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2017,1,20]]},"reference":[{"key":"2025121410594597000_7.1.e011781.1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1467-789X.2006.00291.x"},{"key":"2025121410594597000_7.1.e011781.2","doi-asserted-by":"publisher","DOI":"10.1001\/archpedi.158.1.27"},{"key":"2025121410594597000_7.1.e011781.3","doi-asserted-by":"publisher","DOI":"10.1111\/j.1467-789X.2004.00133.x"},{"key":"2025121410594597000_7.1.e011781.4","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2016.6361"},{"key":"2025121410594597000_7.1.e011781.5","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0069860"},{"key":"2025121410594597000_7.1.e011781.6","doi-asserted-by":"publisher","DOI":"10.1111\/j.1467-789X.2010.00810.x"},{"key":"2025121410594597000_7.1.e011781.7","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199709253371301"},{"key":"2025121410594597000_7.1.e011781.8","doi-asserted-by":"publisher","DOI":"10.1038\/ijo.2010.222"},{"key":"2025121410594597000_7.1.e011781.9","first-page":"146","article-title":"Social inequality in birth weight. 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