Correlation of Vitamin D Levels in Term Normotensive and Pre-eclamptic Patients in Labor

To evaluate maternal vitamin D levels in term normotensive and preeclamptic patients in labor and to assess additional factors such as maternal and cord blood levels of calcium, phosphorus, parathormone, and alkaline phosphatase and associated factors such as BMI, birth weight, and mode of delivery.

This was a case control study carried out in Department of Obstetrics and Gynaecology, ESIC-PGIMSR, New Delhi, India from August 2012-April 2014. A total of 100 patients were divided into two equal groups (control and study groups of 50 each). Control group had women with singleton uncomplicated, term normotensive pregnant women in labor while the study group composed of term preeclamptic women in labor. Blood samples were drawn for vitamin D, serum calcium, serum phosphorus, serum alkaline phosphatase, and serum parathormone levels during first stage of labor, and subsequently, their levels were evaluated in cord blood also.

All the enrolled patients had vitamin D deficiency pointing toward a universal prevalence of this micronutrient deficiency in antenatal patients. We found more incidence of severe vitamin D deficiency (90 %) in preeclamptic patients as compared to normotensive patients (62 %). Also preeclamptic group had lower median vitamin D levels (3.9 ng/ml) when compared to normotensive group (9 ng/ml). Similarly, all the neonates were found to be vitamin D deficient as assessed by their cord blood levels. Neonates born to preeclamptic mothers had lower median cord blood vitamin D levels (4.4 ng/ml) when compared to those born to normotensive mothers (7.25 ng/ml). The mean maternal calcium levels followed trends observed in vitamin D levels with preeclamptic patients having consistently lower calcium levels (mean value of 8.50 ± 0.80 mg/dl) when compared to normotensive patients (mean value of 8.89 ± 0.56 mg/dl). Preeclamptic group was found to have more number of patients (58 %) with higher BMI when compared to normotensive group (32 % of patients). A slightly more incidence (36 %) of low birth weight babies is being born to preeclamptic mothers as compared to normotensive mothers (34 %). Significantly a more number of patients (36 %) with vitamin D levels below 15 ng/ml underwent cesarean section when compared to only 9 % of patients having vitamin D level above this level.

Preeclampsia is indeed associated with lower vitamin D levels, and its pathophysiology involves vitamin D and calcium metabolism.