title: Associations of maternal circulating 25-hydroxyvitamin D3 concentration with pregnancy and birth outcomes.
abstract: OBJECTIVE
  To investigate the association of maternal circulating 25-hydroxyvitamin D3 [25(OH)D3] concentration with pregnancy and birth outcomes.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Four geographical areas of Spain, 2003-2008.
  
  
  METHODS
  Of 2382 mother-child pairs participating in the INfancia y Medio Ambiente (INMA) Project.
  
  
  METHODS
  Maternal circulating 25(OH)D3 concentration was measured in pregnancy (mean [SD] 13.5 [2.2] weeks of gestation). We tested associations of maternal 25(OH)D3 concentration with pregnancy and birth outcomes.
  
  
  METHODS
  Gestational diabetes mellitus (GDM), preterm delivery, caesarean section, fetal growth restriction (FGR) and small-for-gestational age (SGA), anthropometric birth outcomes including weight, length and head circumference (HC).
  
  
  RESULTS
  Overall, 31.8% and 19.7% of women had vitamin D insufficiency [25(OH)D3 20-29.99 ng/ml] and deficiency [25(OH)D3 < 20 ng/ml], respectively. After adjustment, there was no association between maternal 25(OH)D3 concentration and risk of GDM or preterm delivery. Women with sufficient vitamin D [25(OH)D3 ≥ 30 ng/ml] had a decreased risk of caesarean section by obstructed labour compared with women with vitamin D deficiency [relative risk (RR) = 0.60, 95% CI 0.37, 0.97). Offspring of mothers with higher circulating 25(OH)D3 concentration tended to have smaller HC [coefficient (SE) per doubling concentration of 25(OH)D3, -0.10 (0.05), P = 0.038]. No significant associations were found for other birth outcomes.
  
  
  CONCLUSIONS
  This study did not find any evidence of an association between vitamin D status in pregnancy and GDM, preterm delivery, FGR, SGA and anthropometric birth outcomes. Results suggest that sufficient circulating vitamin D concentration [25(OH)D3 ≥ 30 ng/ml] in pregnancy may reduce the risk of caesarean section by obstructed labour.
authors.affiliation: Hospital de Sabadell, Corporació Sanitària Parc Taulí, Institut Universitari ParcTaulí-UAB, Sabadell, Catalonia, Spain.|Universitat Autònoma de Barcelona, Campus d'Excelència Internacional Bellaterra, Catalonia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rodriguez
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain.|Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain.|CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain.
authors.forename: R
authors.initials: R
authors.lastname: García-Esteban
authors.affiliation: CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Department of Health of the Basque Government, Subdirección de Salud Pública de Gipuzkoa, San Sebastian, Spain.|BIODONOSTIA Health Research Institute, San Sebastian, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Basterretxea
authors.affiliation: BIODONOSTIA Health Research Institute, San Sebastian, Spain.|Universidad del País Vasco, EHU-UPV, País Vasco, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Lertxundi
authors.affiliation: CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Center for Public Health Research (CSISP-FISABIO), Valencia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Rodríguez-Bernal
authors.affiliation: CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Center for Public Health Research (CSISP-FISABIO), Valencia, Spain.|University of Valencia, Valencia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Iñiguez
authors.affiliation: Hospital San Agustín, Avilés, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Rodriguez-Dehli
authors.affiliation: CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Universidad de Oviedo, Oviedo, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Tardón
authors.affiliation: Clinical Chemistry Unit, Public Health Laboratory of Bilbao, Euskadi, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Espada
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain.|Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain.|CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sunyer
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain.|Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain.|CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Morales
mesh_terms: D000328:Adult; D002112:Calcifediol / Q000097:blood* / Q000627:therapeutic use; D016640:Diabetes, Gestational / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D009035:Mothers / Q000706:statistics & numerical data*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D047928:Premature Birth; D011446:Prospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D002112:Calcifediol
keywords: Birthweight; caesarean section; gestational diabetes; pregnancy; preterm delivery; vitamin D