Association between Maternal Vitamin D Levels and Risk of Preeclampsia: A Prospective Cohort Study

Dr. Hinalben Ishvarbhai Vaghani; Dr. Hasty Maldebhai Nandaniya; Dr. Bhakti Umesh Zaveri

Authors

Dr. Hinalben Ishvarbhai Vaghani MBBS, DNB OBGY, Department of Obstetrics and Gynaecology, Rhythm Multispeciality Hospital, Kadi, Gujarat, India. Author
Dr. Hasty Maldebhai Nandaniya MBBS, Shantabaa Medical College, Amreli, Gujarat, India. Author
Dr. Bhakti Umesh Zaveri MBBS Graduate, AMC MET Medical College, Ahmedabad, Gujarat, India. Author

Keywords:

25-Hydroxyvitamin D, Preeclampsia, Pregnancy, Prospective Cohort, Vitamin D Deficiency, Hypertensive Disorders of Pregnancy.

Abstract

Background: Vitamin D has immunomodulatory, vascular and placental effects that could affect the pathogenesis of preeclampsia, but prospective evidence is inconsistent. The aim of the study was to examine the relationship between 25-hydroxyvitamin D [25(OH)D] levels in the first trimester and the risk of preeclampsia.

Methods: This was a prospective cohort study of 438 women with singleton pregnancies who were enrolled at 11-14 weeks of gestation and followed to delivery (420 women completed follow-up). The serum 25(OH)D level was assessed at recruitment and classified as deficient (<20 ng/mL), insufficient (20-29.9 ng/mL), or sufficient (>=30 ng/mL). Preeclampsia was diagnosed according to standard criteria and monitored in participants. After adjustment for maternal age, BMI, parity, family history of hypertensive disorders, season of sampling and vitamin D supplement use by multivariable logistic regression.

Results: 40/420 women (9.5%) developed preeclampsia. The mean baseline 25(OH)D level was significantly lower in women who developed preeclampsia than in normotensive women (17.9 +/- 7.4 ng/mL vs 25.5 +/- 9.8 ng/mL; P < 0.001). The prevalence of Preeclampsia was 14.7% in the vitamin D deficient women, 7.0% in the insufficient women and 4.6% in the sufficient women (P for trend = 0.006). Vitamin D deficiency was associated with a 3.08-fold increase in the odds of preeclampsia after adjustment (adjusted odds ratio 3.08; 95% confidence interval 1.12-8.48; P = 0.029). For every 5 ng/mL increase in 25(OH)D, adjusted odds were 20% lower (adjusted odds ratio 0.80; 95% confidence interval 0.69-0.92; P = 0.002).

Conclusion: A lower 25(OH) D level in early pregnancy was independently associated with a higher risk of preeclampsia later in pregnancy. Vitamin D status could be used for risk stratification, but trials of intervention are required before a preventive effect of supplementation could be inferred.