Lower Maternal and Fetal Vitamin D Status and Higher Placental and Umbilical Vitamin D Receptor Expression in Preeclamptic Pregnancies.

Objective: To explore associations between maternal and fetal vitamin D status in preeclamptic pregnancies. Methods: A case-control experiment was carried out with proportion ratio of 1: 1 (controls: n = 60 vs cases: n = 60). Blood collection of both maternal and cord were performed before and during delivery, respectively, and 25(OH) D measurement was conducted. Difference analysis was performed according to returned data. Immunohistochemical analysis, together with semi-quantitative Western blot, was also performed to determine protein expression of vitamin D receptor in placenta and cord tissues of ESPE. Results: Mean +/- SD values of maternal 25(OH) D in control and PE group were 38.06 +/- 6.28 and 33.05 +/- 4.10, respectively, and significant differences with P < 0.0001 were found between control and PE in both continuous and categorical variables, especially in ESPE subtype (32.96 +/- 4.49). The deficiency category (< 30 nmol/L) showed increased odds of PE (OR, 2.83, 95% CI, 1.32-6.08) in both maternal 25(OH) D and cord 25(OH) D in multivariable logistic regression. Semi-quantitative analysis showed that expression of placenta VDR in the ESPE subgroup was significantly higher than that in control group with P < 0.001, while expression of umbilical vein VDR in ESPE subgroup was significantly higher than that in control group with P < 0.05. Conclusions: The present study finds that lowest maternal and fetal vitamin D status in ESPE existed in the preeclampsia subsets. The VDR expression in placenta and fetus in ESPE were higher than that of normal pregnancy, which indicated that it might be related to placenta compensatory mechanism and is worthy of further research.