Associations of maternal circulating 25-hydroxyvitamin D3 concentration with pregnancy and birth outcomes

BJOG. 2015 Nov;122(12):1695-704. doi: 10.1111/1471-0528.13074. Epub 2014 Sep 11.


Objective: To investigate the association of maternal circulating 25-hydroxyvitamin D3 [25(OH)D3] concentration with pregnancy and birth outcomes.

Design: Prospective cohort study.

Setting: Four geographical areas of Spain, 2003-2008.

Population: 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.

Main outcome measures: 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.

Conclusion: 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.

Keywords: Birthweight; caesarean section; gestational diabetes; pregnancy; preterm delivery; vitamin D.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Calcifediol / blood*
  • Calcifediol / therapeutic use
  • Diabetes, Gestational / blood
  • Diabetes, Gestational / etiology*
  • Diabetes, Gestational / prevention & control
  • Female
  • Humans
  • Infant, Newborn
  • Infant, Small for Gestational Age
  • Mothers / statistics & numerical data*
  • Pregnancy
  • Pregnancy Complications / blood
  • Pregnancy Complications / etiology*
  • Pregnancy Complications / prevention & control
  • Premature Birth
  • Prospective Studies
  • Risk Factors
  • Spain / epidemiology
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / complications*
  • Vitamins / therapeutic use*


  • Vitamins
  • Calcifediol