Factors Associated with Progression to Preeclampsia with Severe Features in Pregnancies Complicated by Mild Hypertensive Disorders

In this retrospective cohort study, we aimed to investigate the variables associated with progression to preeclampsia with severe features in parturients already diagnosed with mild hypertensive disorders of pregnancy. The study was conducted in a single university-affiliated medical center between 2018 and 2020. All women admitted due to hypertensive disorders were included. Data collected was compared between parturients who progressed and did not progress to preeclampsia with severe features. Among 359 women presenting without severe features, 18 (5%) developed severe features, delivered smaller babies at lower gestational age, and with higher rates of cesarean delivery (p < 0.001 for all). Chronic hypertension, maternal diabetes, any previous gestational hypertensive disorder, gestational diabetes, number of hospitalizations, earlier gestational age at initial presentation, and superimposed preeclampsia as the preliminary diagnosis were all associated with preeclampsia progression to severe features. Previous delivery within 2-5 years was a protective variable from preeclampsia progression. Following regression analysis and adjustment to confounders, only gestational age at initial presentation and superimposed preeclampsia remained significant variables associated with progression to severe features (aOR 0.74 (0.55-0.96) and 34.44 (1.07-1111.85), aOR (95% CI), respectively, p < 0.05 for both) with combined ROC-AUC prediction performance of 0.89, 95% CI 0.83-0.95, p < 0.001. In conclusion, according to our study results, early gestational age at presentation and superimposed preeclampsia as the preliminary diagnosis are the only independent factors that are associated with progression to severe features in women already diagnosed with mild hypertensive disorders during pregnancy.