Trends in gestational age at delivery for intrahepatic cholestasis of pregnancy and adoption of society guidelines

Abstract

Background: Intrahepatic cholestasis of pregnancy is associated with a significant risk of stillbirth, which contributes to variation in clinical management. Recent Society for Maternal-Fetal Medicine guidance recommends delivery at 36 weeks of gestation for patients with serum bile acid levels of >100 μmol/L, consideration for delivery between 36 and 39 weeks of gestation stratified by bile acid level, and against preterm delivery for those with clinical features of cholestasis without bile acid elevation.

Objective: This study aimed to investigate institutional practices before the publication of the new delivery timing recommendations to establish the maternal and neonatal effects of late preterm, early-term, and term deliveries in the setting of cholestasis.

Study design: This study examined maternal and neonatal outcomes of 441 patients affected by cholestasis delivering 484 neonates in a 4-hospital system over a 30-month period. Logistic and linear regression analyses were performed to assess neonatal outcomes concerning peak serum bile acid levels at various gestational ages controlling for maternal comorbidities, multiple pregnancies, and neonatal birthweight.

Results: With the clinical flexibility afforded by the new guidelines, pregnancy prolongation to term may have been achieved in 91 patients (21%), and 286 patients (74%) with bile acid elevation could have delivered at a later gestational age. Preterm deliveries of patients with bile acid levels of >10 μmol/L were associated with higher rates of neonatal intensive care unit admission and adverse neonatal outcomes than early-term deliveries.

Conclusion: Study data suggested an opportunity for education and practice change to reflect current Society for Maternal-Fetal Medicine guidelines in efforts to reduce potential neonatal morbidities associated with late preterm deliveries among pregnancies affected by cholestasis.

Keywords: bile acids; intrahepatic cholestasis of pregnancy; neonatal morbidity; practice variation; prematurity; pruritus; stillbirth.