Maternal vitamin D status and small-for-gestational-age offspring in women at high risk for preeclampsia.
OBJECTIVE
To examine the association between second-trimester maternal serum 25-hydroxyvitamin D concentrations and risk of small for gestational age (SGA) in singleton live births.


METHODS
We assayed serum samples at 12-26 weeks of gestation for 25-hydroxyvitamin D in a sample of participants in a multicenter clinical trial of low-dose aspirin for the prevention of preeclampsia in high-risk women (n=792). Multivariable log-binomial regression models were used to assess the association between 25-hydroxyvitamin D and risk of SGA (birth weight less than the 10 percentile for gestational age) after adjustment for confounders including maternal prepregnancy obesity, race, treatment allocation, and risk group.


RESULTS
Thirteen percent of neonates were SGA at birth. Mean (standard deviation) 25-hydroxyvitamin D concentrations were lower in women who delivered SGA (57.9 [29.9] nmol/L) compared with non-SGA neonates (64.8 [29.3] nmol/L, P=.028). In adjusted models, 25-hydroxyvitamin D concentrations of 50-74 nmol/L and 75 nmol/L or greater compared with less than 30 nmol/L were associated with 43% (95% confidence interval [CI] 0.33-0.99) and 54% (95% CI 0.24-0.87) reductions in risk of SGA, respectively. Race and maternal obesity each modified this association. White women with 25-hydroxyvitamin D 50 nmol/L or greater compared with less than 50 nmol/L had a 68% reduction in SGA risk (adjusted risk ratio 0.32, 95% CI 0.17-0.63) and nonobese women with 25-hydroxyvitamin D 50 nmol/L or greater compared with less than 50 nmol/L had a 50% reduction in SGA risk (adjusted risk ratio 0.50, 95% CI 0.31-0.82). There was no association between 25-hydroxyvitamin D and risk of SGA in black or obese mothers.


CONCLUSIONS
Maternal vitamin D status in the second trimester is associated with risk of SGA among all women and in the subgroups of white and nonobese women.


METHODS
II.
Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, the Division of Maternal-Fetal Medicine, Magee-Women's Hospital, and the Departments of Obstetrics, Gynecology and Reproductive Sciences and Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
Alison D
AD
Gernand
Hyagriv N
HN
Simhan
Steve
S
Caritis
Lisa M
LM
Bodnar
D000328:Adult; D001724:Birth Weight; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D064887:Observational Studies as Topic; D011225:Pre-Eclampsia / Q000097:blood / Q000517:prevention & control; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D014807:Vitamin D / Q000097:blood*; D055815:Young Adult
D014807:Vitamin D