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Maternal Serum 25‐Hydroxyvitamin D Concentrations during Pregnancy and Infant Birthweight for Gestational Age: a Three‐Cohort Study
Author(s) -
Tian Yan,
Holzman Claudia,
SiegaRiz Anna M.,
Williams Michelle A.,
Dole Nancy,
Enquobahrie Daniel A.,
Ferre Cynthia D.
Publication year - 2016
Publication title -
paediatric and perinatal epidemiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 88
eISSN - 1365-3016
pISSN - 0269-5022
DOI - 10.1111/ppe.12262
Subject(s) - medicine , obstetrics , pregnancy , gestational age , cohort , cohort study , vitamin d and neurology , gestation , pediatrics , endocrinology , genetics , biology
Background In response to inconsistent findings, we investigated associations between maternal serum 25‐hydroxyvitamin D [25( OH ) D ] concentrations and infant birthweight for gestational age ( BW / GA ), including potential effect modification by maternal race/ethnicity and infant sex. Methods Data from 2558 pregnant women were combined in a nested case–control study (preterm and term) sampled from three cohorts: the O mega study, the P regnancy, I nfection and N utrition study, and the P regnancy O utcomes and C ommunity H ealth study. Maternal 25( OH ) D concentrations were sampled at 4 to 29 weeks gestation (80% 14–26 weeks). BW / GA was modelled as sex and gestational age‐specific birthweight z‐scores. General linear regression models (adjusting for age, education, parity, pre‐pregnancy body mass index, season at blood draw, and smoking) assessed 25( OH )D concentrations in relation to BW / GA . Results Among non‐Hispanic Black women, the positive association between 25( OH ) D concentrations and BW / GA was of similar magnitude in pregnancies with female or male infants [beta (β) = 0.015, standard error ( SE ) = 0.007, P = 0.025; β = 0.018, SE = 0.006, P = 0.003, respectively]. Among non‐ H ispanic W hite women, 25( OH )D‐ BW / GA association was observed only with male infants, and the effect size was lower (β = 0.008, SE = 0.003, P = 0.02). Conclusions Maternal serum concentrations of 25( OH )D in early and mid‐pregnancy were positively associated with BW / GA among non‐ H ispanic B lack male and female infants and non‐ H ispanic W hite male infants. Effect modification by race/ethnicity may be due, in part, to overall lower concentrations of 25( OH ) D in non‐ H ispanic B lacks. Reasons for effect modification by infant sex remain unclear.