Longitudinal vitamin D status in pregnancy and the risk of pre‐eclampsia

SQ Wei, F Audibert, N Hidiroglou… - … Journal of Obstetrics …, 2012 - Wiley Online Library
SQ Wei, F Audibert, N Hidiroglou, K Sarafin, P Julien, Y Wu, ZC Luo, WD Fraser
BJOG: An International Journal of Obstetrics & Gynaecology, 2012Wiley Online Library
Please cite this paper as: Dr Wei SQ, Audibert F, Hidiroglou N, Sarafin K, Julien P, Wu Y,
Luo ZC, Fraser WD. Longitudinal vitamin D status in pregnancy and the risk of pre‐
eclampsia. BJOG 2012; 119: 832–839. Objective Whether vitamin D deficiency in pregnancy
is a cause of pre‐eclampsia remains controversial. Most previous studies to date have
assessed exposure at only one time‐point in pregnancy. We assessed longitudinal vitamin
D status during pregnancy and the risk of pre‐eclampsia. Design Prospective cohort study …
Please cite this paper as: Dr Wei SQ, Audibert F, Hidiroglou N, Sarafin K, Julien P, Wu Y, Luo ZC, Fraser WD. Longitudinal vitamin D status in pregnancy and the risk of pre‐eclampsia. BJOG 2012;119:832–839.
Objective  Whether vitamin D deficiency in pregnancy is a cause of pre‐eclampsia remains controversial. Most previous studies to date have assessed exposure at only one time‐point in pregnancy. We assessed longitudinal vitamin D status during pregnancy and the risk of pre‐eclampsia.
Design  Prospective cohort study.
Setting  Seventeen urban obstetric hospitals, Canada.
Population  Pregnant women who were participants in a trial of vitamin C and E supplementation for the prevention of pre‐eclampsia. Canadian participants who consented to participate in a biobank with plasma specimens available at the baseline visit were included (n = 697).
Methods  Maternal plasma 25‐hydroxyvitamin D (25(OH)D) concentrations were measured at 12–18 and 24–26 weeks of gestation using chemiluminescence immunoassay.
Main outcome measures  Pre‐eclampsia.
Results  Of the women, 39% were vitamin D deficient (25(OH)D <50 nmol/l). A strong positive correlation was observed in maternal 25(OH)D concentrations between the two gestational age windows (r = 0.69, P < 0.0001). Mean maternal 25(OH)D concentrations at 24–26 weeks of gestation were significantly lower in women who subsequently developed pre‐eclampsia compared with those who did not (mean ± SD: 48.9 ± 16.8 versus 57.0 ± 19.1 nmol/l, P = 0.03). Women with 25(OH)D < 50 nmol/l at 24–26 weeks gestation experienced an increased risk of pre‐eclampsia (adjusted odds ratio 3.24, 95% confidence interval 1.37–7.69), whereas the association was not statistically significant for maternal 25(OH)D level at 12–18 weeks of gestation.
Conclusions  Lower maternal 25(OH)D levels at late mid‐trimester were associated with an increased risk of pre‐eclampsia.
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