Association between Vitamin D Deficiency and Preeclampsia: A Case Control Study

Abstract

Summary P reeclampsia is a pregnancy-specific disorder that affects 3–5% of pregnant women worldwide and is one of the most frequently encountered medical complication of pregnancy. Hypertension is one of the most common medical complications of pregnancy. It remains one of the leading causes of maternal deaths all over the world. Early detection and appropriate management of the pregnancy may improve the outcome for both the mother and the fetus. Despite growing knowledge of the pathophysiology of pregnancy induced hypertensive disorders, there is no preventive measures have been shown to be effective. Recent research has pointed towards some role of vitamin D deficiency in pathogenesis of preeclampsia.Vitamin D deficiency in pregnant women and their children is a major health problem, with potential adverse consequences for overall health. Vitamin D deficiency correlates with many other adverse effects such as infertility, gestational diabetes mellitus, bacterial vaginosis, preterm labour,low birth weight and an increased risk for cesarean delivery. During pregnancy and lactation, significant changes in maternal vitamin D and calciummetabolism occur to provide the calcium that is needed for fetal bone mineral accretion. Compared to normal pregnancies, vitamin D metabolism is markedly altered in pre-eclampsia. This may be due to reduced placental 1α-hydroxylase activityresulting in lower circulating calcitriol concentrations compared to normotensive pregnant women. Vitamin D inhibits the mRNA transcription of inflammatory cytokine genes (TNFα, IFNγ and IL-6) in trophoblast cell. Immune challenge by lipopolysaccharide induces the expression of VDR and CYP27B1 along with cytokines such as IL-6 in placenta. The increase in the number of studies on this subject shows conflicting results on the association between 25(OH)D levels in pregnancy and adverse effects on maternal and fetal health, both skeletal and non-skeletal such as autoimmune diseases, cardiovascular diseases, diabetes and certain types of cancer. The current study aimed to compare Serum 25 hydroxy vitamin D levels among patients with preeclampsia and healthy normotensive pregnant women. A case-control study was conducted at Ain Shams University Maternity Hospital as 90primigravida women, between 18-35 years, with Singleton pregnancy, after 36 weeks of gestation without any other medical disorders.They were classified into 2 groups: - Group (1): 45 preeclamptic women. - Group (2): 45 normotensive women. Preeclampsia was defined as a systolic blood pressure greater than or equal to 140 mm Hg and/or diastolic blood pressure greater than or equal to 90 mmHg and the presence of +1 or more of proteinuria after 20 weeks of gestation. Deficiency of vitamin D level in pregnant women was defined as serum level < 20 ng/ml, insufficiency as21-30 ng/ml and optimum level as > 30 ng/ml. All samples were screened by DRG® 25-OH Vitamin D (total) ELISA (EIA-5396) and it was found that mean25 hydroxy vitamin D levels were lower in preeclamptic group than normotensive control group. Mean level of25 hydroxy vitamin D between preeclamptic cases was 11.98 ±5.43 ng/ml and between normotensive controls was12.33±10.48ng/ml.