Proteinuria is a clinical characteristic of intrahepatic cholestasis of pregnancy but it is not a marker of severity: A retrospective cohort study

Objectives To determine the prevalence of proteinuria in patients diagnosed with intrahepatic cholestasis of pregnancy (IHCP), and the association between the presence of proteinuria and adverse pregnancy outcomes. Methods This was a retrospective cohort study. The study included all pregnant patients between July 2014 and January 2022, at gestational age > 24weeks who had been diagnosed with IHCP and had completed a 24-hour protein collection. High order multifetal gestations were excluded. Patients were divided into 3 groups:1. IHCP without proteinuria (Non-proteinuric group);2. IHCP with proteinuria and normal blood pressure (Isolated proteinuria group), and 3. IHCP with proteinuria and elevated blood pressure (IHCP with preeclampsia (PET)). Primary outcome was defined as a composite maternal-fetal outcome including: preterm labor <34 weeks, arterial cord blood ph<7.1, rate of Cesarean delivery due to non-reassuring fetal monitoring. Parametric and non-parametric statistical methods were used for analysis. Results A total of 272 met all inclusion criteria and were included, 94 patients (34.5%) had proteinuria; of them, 67 (24.6%) had isolated proteinuria and 27 (9.9%) had PET. Demographic parameters were comparable among the groups. Patients with PET had higher rates of in-vitro fertilization (IVF) treatments, twin gestation and elevated serum creatinine and urea levels. The rate of composite adverse pregnancy outcome was higher in patients with PET compared with patients with and without proteinuria (14/27 (51.9%) vs. 18/67 (26.9%) vs. 49/178 (27.5%), respectively, p = 0.03). Conclusions Approximately 35% of patients with IHCP have proteinuria. The presence of PET, rather than isolated proteinuria, is associated with adverse pregnancy outcome.