High Prevalence of Vitamin D deficiency among normotensive and hypertensive pregnant women in Ghana

Abstract Background: Hypovitaminosis D in pregnancy is associated with adverse health outcomes in mothers, newborns and infants. This study assessed the levels of 25-hydroxyvitamin D [25(OH)D] in normotensive pregnancies and pregnancies complicated by preeclampsia, and evaluated the association between vitamin D deficiency and foeto-maternal outcome. Methods: This case-control study was conducted among pregnant women who visited the Comboni Hospital, in Ghana from January 2017 to May 2018 for antenatal care. A total of 180 pregnant women comprising 88 preeclamptic women (PE) and 92 healthy normotensive pregnant women (NP) were recruited. Socio-demographic, clinical and obstetric data were obtained using validated questionnaires. Blood pressure and anthropometrics were measured, and blood samples were collected for the estimation of 25(OH)D using enzyme-linked immunosorbent assay technique. Lipids (total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol) and were also estimated. Results: A total of 81.7% of the study participants had vitamin D deficiency. Of these, 88.6% of the women with PE had vitamin D deficiency compared to 75.0% in the NP. Vitamin D levels was significantly reduced in the PE women compared to the normotensive pregnant women (p=0.001). A higher proportion of the preeclamptic women who were vitamin D deficient had preterm delivery (p < 0:0001) and delivered low birth weight infants (p < 0:0001), and infants with IUGR (p < 0:0001) compared to the control group (p < 0:0001). Pregnant women with PE presented with significant dyslipidaemia, evidenced by significantly elevated TC (p=0.008), LDL (p<0.0001), triglycerides (p=0.017) and a significantly reduced HDL (p=0.001) as compared to NP. In the preeclamptic women, serum 25(OH)D showed an inverse, but not significant association with TC (β= -0.087, p=0.464), TG (β= -0.143, p=0.233) and LDL (β= -0.101, p=0.388) and a positive, but not significant association with HDL (β= 0.166, p=0.154). Conclusion: The prevalence of vitamin D deficiency is high in both normotensive pregnancies and pregnancies complicated by preeclampsia but amplified in preeclampsia. Higher proportion of pregnant women with hypovitaminosis D had preterm babies and delivered low birth weight neonates. Additional studies are needed to explore the potential benefits and optimal dosing of vitamin D use in pregnancy especially in sub-Saharan Africa.