Progression from isolated gestational proteinuria to preeclampsia with severe features

Introduction: The association between the degree of isolated gestational proteinuria and preeclampsia with severe features and other placental-mediated complications is controversial. The aim of this study was to evaluate whether a higher isolated proteinuria level is associated with an increased frequency of preeclampsia with severe features. Material and methods: This retrospective cohort study included pregnant women who were past 24 weeks of gestation and were diagnosed as having new-onset proteinuria ≥300 mg in a 24-h urine collection. Exclusion criteria included diagnosis of preeclampsia within 72 h from admission, chronic renal disease or chronic hypertension. The study population was divided into tertiles by proteinuria level and the association with preeclampsia with severe features was assessed in both bivariable and multivariable analysis. The main outcome measures was the development of preeclampsia with severe features. Results: Overall, 165 women were diagnosed with isolated gestational proteinuria, and 38 (23.0%) of them developed preeclampsia with severe features. Women in the increasing proteinuria tertile were more likely to develop preeclampsia with severe features (5.5%, 21.8%, 41.8%, respectively; p = 0.004). A multivariable logistic regression model controlling for background characteristics as well as gestational age at diagnosis, blood pressure, and kidney and liver function tests showed an increased risk of 14% to develop preeclampsia with severe features for every 500-mg rise in proteinuria level (adjusted odds ratio = 1.14, 95% confidence interval 1.03–1.27). Conclusions: A higher isolated gestational proteinuria level was associated with an increased risk to develop preeclampsia with severe features among pregnant women past 24 weeks of gestation.