title: Maternal vitamin D deficiency during pregnancy elevates the risks of small for gestational age and low birth weight infants in Chinese population.
abstract: BACKGROUND
  Vitamin D deficiency is common in pregnant women. Nevertheless, the association between maternal vitamin D status during pregnancy and the risk of having small for gestational age (SGA) and low birth weight (LBW) infants is uncertain.
  
  
  OBJECTIVE
  The objective of this study was to investigate whether there is a correlation between maternal vitamin D deficiency during pregnancy and the risk of having SGA and LBW infants in a Chinese population.
  
  
  METHODS
  This was a population-based birth cohort study that recruited 3658 eligible mother-and-singleton-offspring pairs.
  
  
  METHODS
  Serum 25-hydroxyvitamin D was measured by RIA. The rate and relative risk (RR) for SGA and LBW infants were calculated among subjects with vitamin D deficiency and insufficiency during pregnancy.
  
  
  RESULTS
  There was a positive correlation between maternal serum 25-hydroxyvitamin D level and offspring birth weight (r = 0.477; P < .001). Further analysis showed that 4.98% of neonates were LBW infants among the subjects with vitamin D deficiency (RR, 12.00; 95% confidence interval [CI], 4.37, 33.00) and 1.32% among the subjects with vitamin D insufficiency (RR, 3.18; 95% CI, 1.07, 9.48). After adjustment for confounders, the RR for LBW infants was 12.31 (95% CI, 4.47, 33.89) among subjects with vitamin D deficiency and 3.15 (95% CI, 1.06, 9.39) among subjects with vitamin D insufficiency. Moreover, 16.01% of neonates were SGA infants among subjects with vitamin D deficiency (RR, 5.72; 95% CI, 3.80, 8.59) and 5.59% among subjects with vitamin D insufficiency (RR, 1.99; 95% CI, 1.27, 3.13). After adjustment for confounders, the RR for SGA infants was 6.47 (95% CI, 4.30, 9.75) among subjects with vitamin D deficiency and 2.01 (95% CI, 1.28, 3.16) among subjects with vitamin D insufficiency.
  
  
  CONCLUSIONS
  Maternal vitamin D deficiency during pregnancy elevates the risk of SGA and LBW infants in a Chinese population.
authors.affiliation: School of Public Health (Y.-H.C., L.F., J.-H.H., Z.Y., P.Z., H.W., Y.-Y.X., C.Z., F.-B.T., D.-X.X.), Anhui Provincial Key Laboratory of Population Health and Aristogenics (Y.-H.C., J.-H.H., P.Z., Y.-Y.X., C.Z., F.-B.T., D.-X.X.), and School of Basic Medical Science (Y.-H.C.), Anhui Medical University, Hefei 230032, China.
authors.forename: Yuan-Hua
authors.initials: YH
authors.lastname: Chen
authors.forename: Lin
authors.initials: L
authors.lastname: Fu
authors.forename: Jia-Hu
authors.initials: JH
authors.lastname: Hao
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yu
authors.forename: Peng
authors.initials: P
authors.lastname: Zhu
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Xu
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Fang-Biao
authors.initials: FB
authors.lastname: Tao
authors.forename: De-Xiang
authors.initials: DX
authors.lastname: Xu
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D002681:China; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D009035:Mothers; D011247:Pregnancy; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D