Vitamin D Status and the Determinants of Preeclampsia in Pregnant Women in Goma (Democratic Republic of the Congo)

Background: Preeclampsia (PE) is a common condition, causing maternal and perinatal morbidity and mortality worldwide. In the absence of fully satisfactory treatment, screening remains one of the pillars of management. Low vitamin D status has been identified as a risk factor for PE. But, data on vitamin D status and risk factors for PE in the Democratic Republic of the Congo (DRC) is scanty. The aim of this study is to determine the level of Vitamin D and risk factors in preeclamptic patients in our environment. Methods: To fill this gap, we conducted a multicenter incident case control study on 190 pregnant women, 95 cases and 95 controls, receiving care from seven hospitals in Goma, in the eastern DRC, from April 1 to December 31, 2019. Socioeconomic, diet habits, clinical data, urinalysis and serum 25-hydroxy vitamin D [25(OH)D] levels were analyzed. Vitamin D deficiency was defined as serum 25(OH)D < 30 ng/ml. Bivariate and multivariate analysis were used to assess risk factors of PE. Results: The median vitamin D level in preeclamptic women was lower than in the control group (21.7 [Interquartile Range (IQR) = 19.2 - 24.1] ng/ml versus 28.5 [IQR = 24.9 - 31.4] ng/ml;(p < 0.001). PE was associated with: 1) vitamin D deficiency, Odds Ratio (OR) = 2.77 at 95% Confidence Interval-CI of [1.22 - 6.31];p = 0.015; 2) previous history of PE (OR = 12.30;95% CI [1.92 - 18.98];p = 0.008) and 3) high BMI (OR = 2.82;95% CI [1.28 - 6.21];p = 0.010). Smoking (OR = 0.33;95% CI [0.22 - 0.98];p = 0.015) and consumption of dairy products (OR = 0.39;95% CI [0.17 - 0.92];p = 0.032) were protective. Conclusion: The odds of PE were 3-fold in pregnant women with vitamin D deficiency. Vitamin D supplementation during pregnancy might reduce the risk of developing PE and ultimately reduce the consequences on maternal and perinatal advert outcomes.