{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T11:22:41Z","timestamp":1789212161283,"version":"build-2803163510"},"reference-count":35,"publisher":"BMJ","issue":"2","license":[{"start":{"date-parts":[[2020,2,25]],"date-time":"2020-02-25T00:00:00Z","timestamp":1582588800000},"content-version":"unspecified","delay-in-days":24,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002341","name":"Suomen Akatemia","doi-asserted-by":"publisher","award":["285672"],"award-info":[{"award-number":["285672"]}],"id":[{"id":"10.13039\/501100002341","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004037","name":"Juho Vainion S\u00e4\u00e4ti\u00f6","doi-asserted-by":"publisher","award":["201510322"],"award-info":[{"award-number":["201510322"]}],"id":[{"id":"10.13039\/501100004037","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004037","name":"Juho Vainion S\u00e4\u00e4ti\u00f6","doi-asserted-by":"publisher","award":["201610405"],"award-info":[{"award-number":["201610405"]}],"id":[{"id":"10.13039\/501100004037","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004037","name":"Juho Vainion S\u00e4\u00e4ti\u00f6","doi-asserted-by":"publisher","award":["201710136"],"award-info":[{"award-number":["201710136"]}],"id":[{"id":"10.13039\/501100004037","id-type":"DOI","asserted-by":"publisher"}]},{"name":"EU Life project","award":["LIFE15ENV\/PT\/000674"],"award-info":[{"award-number":["LIFE15ENV\/PT\/000674"]}]},{"DOI":"10.13039\/501100004785","name":"NordForsk","doi-asserted-by":"publisher","award":["#75007"],"award-info":[{"award-number":["#75007"]}],"id":[{"id":"10.13039\/501100004785","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005432","name":"Pohjois-Savon Rahasto","doi-asserted-by":"publisher","award":["65161550"],"award-info":[{"award-number":["65161550"]}],"id":[{"id":"10.13039\/501100005432","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2020,1,30]]},"published-print":{"date-parts":[[2020,2]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>The aim of our work was to analyse the effect of maternal smoking on body size and body proportions of newborns when the mother had smoked only during the first trimester, in comparison with continued smoking after the first trimester. Furthermore, we have evaluated how growth restriction associated with maternal smoking contributes to changes in body proportions.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Register-based cohort study<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Maternal Exposure (MATEX) cohort identified from the Finnish Medical Birth Register.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>Singleton births without congenital anomalies and missing data (1.38\u2009million) from 1 January 1991 to 31 December 2016.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Logistic regression was used to quantify the effect of maternal smoking, stratified by the maternal smoking status.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Outcome measures<\/jats:title>\n                    <jats:p>Body proportions indicated by low brain-to-body ratio (defined as &lt;10th percentile); high ponderal index and high head-to-length ratio (defined as &gt;90th percentile); small body size for gestational age at birth (defined as weight, length or head circumference &lt;10th percentile) and preterm birth (&lt;37\u2009weeks) and low birth weight (2500\u2009g).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Continued smoking after the first trimester was associated with high ponderal index (OR 1.26, 95%\u2009CI 1.23 to 1.28), low brain-to-body ratio (1.11, 1.07\u20131.15) and high head-to-length ratio (1.22, 1.19\u20131.26), corresponding with absolute risks of 22%, 10% and 19%, respectively). The effects were slightly lower when smoking had been quit during the first trimester. Similar effects were seen for the body size variables and low birth weight. Preterm birth was not associated with smoking only during first trimester.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Maternal smoking, independent of smoking duration during pregnancy, was associated with abnormal body proportions resulting from larger reduction of length and head circumference in comparison to weight. The effects of having quit smoking during the first trimester and having continued smoking after the first trimester were similar, suggesting the importance of early pregnancy as a sensitive exposure window.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2019-033465","type":"journal-article","created":{"date-parts":[[2020,2,26]],"date-time":"2020-02-26T06:15:17Z","timestamp":1582697717000},"page":"e033465","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":29,"title":["Effects of maternal smoking on body size and proportions at birth: a register-based cohort study of 1.4 million births"],"prefix":"10.1136","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7991-2752","authenticated-orcid":false,"given":"Isabell","family":"Rumrich","sequence":"first","affiliation":[{"name":"Department of Environmental and Biological Sciences, University of Eastern Finland, Faculty of Science and Forestry, Kuopio, Finland"},{"name":"Department of Public Health Solutions, Finnish Institute for Health and Welfare, Kuopio, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kirsi","family":"V\u00e4h\u00e4kangas","sequence":"additional","affiliation":[{"name":"School of Pharmacy\/Toxicology, University of Eastern Finland, Faculty of Health Sciences, Kuopio, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matti","family":"Viluksela","sequence":"additional","affiliation":[{"name":"Department of Environmental and Biological Sciences, University of Eastern Finland, Faculty of Science and Forestry, Kuopio, Finland"},{"name":"School of Pharmacy\/Toxicology, University of Eastern Finland, Faculty of Health Sciences, Kuopio, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mika","family":"Gissler","sequence":"additional","affiliation":[{"name":"Department of Information Services, Finnish Institute for Health and Welfare, Helsinki, Finland"},{"name":"Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Huddinge, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hanna","family":"de Ruyter","sequence":"additional","affiliation":[{"name":"Unit for Obstetrics and Gynecology, Southern Ostrobothnia Central Hospital, Sein\u00e4joki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Otto","family":"H\u00e4nninen","sequence":"additional","affiliation":[{"name":"Department of Public Health Solutions, Finnish Institute for Health and Welfare, Kuopio, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2020,2,25]]},"reference":[{"key":"2025121401282583000_10.2.e033465.1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-3016.2000.00266.x"},{"key":"2025121401282583000_10.2.e033465.2","doi-asserted-by":"publisher","DOI":"10.2174\/157015907781695955"},{"key":"2025121401282583000_10.2.e033465.3","doi-asserted-by":"crossref","DOI":"10.1186\/s12967-015-0690-y","article-title":"Short and long term health effects of parental tobacco smoking during pregnancy and lactation: a descriptive review","volume":"13","author":"Banderali","year":"2015","journal-title":"J Transl Med"},{"key":"2025121401282583000_10.2.e033465.4","doi-asserted-by":"publisher","DOI":"10.1586\/17474108.3.6.719"},{"key":"2025121401282583000_10.2.e033465.5","doi-asserted-by":"crossref","first-page":"4037","DOI":"10.3109\/14767058.2016.1154525","article-title":"Intrauterine growth restriction - 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