{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T00:27:05Z","timestamp":1778804825017,"version":"3.51.4"},"reference-count":37,"publisher":"BMJ","issue":"9","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2016,8,24]]},"published-print":{"date-parts":[[2016,9]]},"abstract":"<jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>Vitamin D deficiency causes not only skeletal problems but also muscle weakness, including heart muscle. If the fetal heart is also affected, it might be more susceptible to fetal distress and birth asphyxia. In this pilot study, we hypothesised that low maternal vitamin D levels are over-represented in pregnancies with fetal distress\/birth asphyxia.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Design and setting<\/jats:title>\n                  <jats:p>A population-based nested case\u2013control study.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Patients<\/jats:title>\n                  <jats:p>Banked sera of 2496 women from the 12th week of pregnancy.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Outcome measures<\/jats:title>\n                  <jats:p>Vitamin D levels were analysed using a direct competitive chemiluminescence immunoassay. Vitamin D levels in early gestation in women delivered by emergency caesarean section due to suspected fetal distress were compared to those in controls. Birth asphyxia was defined as Apgar &lt;7 at 5\u2005min and\/or umbilical cord pH\u22647.15.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Vitamin D levels were significantly lower in mothers delivered by emergency caesarean section due to suspected fetal distress (n=53, 43.6\u00b118\u2005nmol\/L) compared to controls (n=120, 48.6\u00b119\u2005nmol\/L, p=0.04). Birth asphyxia was more common in women with vitamin D deficiency (n=95) in early pregnancy (OR 2.4, 95% CI 1.1 to 5.7).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Low vitamin D levels in early pregnancy may be associated with emergency caesarean section due to suspected fetal distress and birth asphyxia. If our findings are supported by further studies, preferably on severe birth asphyxia, vitamin D supplementation\/sun exposure in pregnancy may lower the risk of subsequent birth asphyxia.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjopen-2015-009733","type":"journal-article","created":{"date-parts":[[2016,9,22]],"date-time":"2016-09-22T22:48:45Z","timestamp":1474584525000},"page":"e009733","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":19,"title":["Maternal vitamin D deficiency and fetal distress\/birth asphyxia: a population-based nested case\u2013control study"],"prefix":"10.1136","volume":"6","author":[{"given":"Pelle G","family":"Lindqvist","sequence":"first","affiliation":[{"name":"Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden"},{"name":"Department of Obstetrics & Gynecology, Karolinska University Hospital, Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aldo T","family":"Silva","sequence":"additional","affiliation":[{"name":"Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sven A","family":"Gustafsson","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sebastian","family":"Gidl\u00f6f","sequence":"additional","affiliation":[{"name":"Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden"},{"name":"Department of Obstetrics & Gynecology, Karolinska University Hospital, Stockholm, Sweden"},{"name":"Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2016,9,22]]},"reference":[{"key":"2025101811473424000_6.9.e009733.1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMra070553"},{"key":"2025101811473424000_6.9.e009733.2","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2013-3241"},{"key":"2025101811473424000_6.9.e009733.3","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1016\/j.atherosclerosis.2007.05.017","article-title":"Lipid management in cardiovascular disease prevention guidelines: strategies and tactics for implementation","volume":"196","author":"Erhardt","year":"2008","journal-title":"Atherosclerosis"},{"key":"2025101811473424000_6.9.e009733.4","doi-asserted-by":"publisher","DOI":"10.1007\/s001980200012"},{"key":"2025101811473424000_6.9.e009733.5","first-page":"28","article-title":"Maternal and foetal outcome of pregnant patients with sickle cell anaemia at Kenyatta National Hospital Nairobi. 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