446: Maternal pregnancy complications associated with intrahepatic cholestasis of pregnancy in a population-based cohort

Abstract

This study aims to estimate the risk of various maternal pregnancy outcomes in women with intrahepatic cholestasis of pregnancy (ICP). This is a retrospective cohort study including 2,250,129 singleton, non-anomalous pregnancies between 24 and 42 weeks and 6 days of gestation recorded in the 2005-2008 California Birth Registry, of which 8,047 were complicated by ICP. Maternal pregnancy outcomes assessed include preeclampsia (PET), severe PET (sPET), gestational hypertension (gHTN), cesarean section (CS) in nulliparous and multiparous women, postpartum hemorrhage (PPH), and chorioamnionitis. Statistical analysis included chi-squared tests and multivariate logistic regression analyses. The prevalence of ICP is 0.36% in our cohort. ICP is associated with an increased risk of PET (6.38% vs. 2.88%, p<0.001), severe PET (2.66% vs. 0.78%, p<0.001), and progression to sPET if diagnosed with PET (41.73% vs. 26.92%, p<0.001). This statistical significance remains even when controlling for independent PET risk factors such as age, race, and diabetes. ICP confers a slightly increased risk of gHTN (3.88% vs. 3.18%, p=0.002). CS risk increased and was higher among nulliparous women (34.18% vs. 29.05%, p<0.001) than in multiparous women (12.53% vs. 10.29%, p<0.001). Additional peripartum morbidities were found to be associated with ICP including chorioamnionitis (2.99% vs. 1.91%, p<0.001) and PPH (5.28% vs. 2.80%, p<0.001). All of these observations, except for gHTN and CS among multiparous women, remained statistically significant when controlling for potential cofounders, including maternal age, ethnicity, educational level, insurance status, and other co-morbid conditions (Table 1). ICP is a rare condition that confers an increased risk of PET, sPET, CS in nulliparous women, PPH, and chorioamnionitis. This observation of significant adverse maternal pregnancy outcomes can be used, in addition to fetal risks reported in literature, to counsel women with ICP.