The impact of proteinuria on maternal and perinatal outcomes among women with pre‐eclampsia

Objective To assess the impact of proteinuria on pregnancy outcomes among women with pre‐eclampsia. Methods The present retrospective cohort study included patients with pre‐eclampsia who delivered at a referral maternity hospital in Brazil between January 1, 2009, and December 31, 2013. Patients were stratified into three groups based on 24‐hour urinary protein excretion during pregnancy: mild (0.3–<2.0 g), severe (2.0–<5.0 g), and massive (≥5.0 g). Results There were 293 patients included in the study; 88, 129, and 76 had mild, severe, and massive proteinuria, respectively. Chronic hypertension was the most frequent pre‐existing condition among all women (86 [29.4%]). The mean pregnancy duration at the onset of maternal pre‐eclampsia was longest in the mild group compared and decreased with increasing proteinuria severity ( P <0.001). Preterm delivery was recorded among 205 of 293 (70.0%) neonates; there were 66 (22.5%) neonates that were preterm and in the massive proteinuria group. The incidence of severe pre‐eclampsia was lowest in the mild proteinuria group ( P =0.002) and tended to occur at 34 weeks. Cesarean delivery rates exceeded 80.0% in all groups. Most patients assessed at 40–60 days postpartum remained proteinuric (40/61[66%]). Conclusions Quantifying the severity of proteinuria could identify a subgroup of women with pre‐eclampsia at increased risk of adverse outcomes.