Preterm Birth and Stillbirth: Total Bile Acid Levels in Intrahepatic Cholestasis of Pregnancy and Outcomes of Twin Pregnancies: A Retrospective Cohort Study from 2014 to 2022

Background Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder characterized by maternal pruritus and elevated serum bile acids. Twin pregnancies, as a type of high-risk pregnancy, present additional complexities when complicated by ICP compared to singleton pregnancies. Our study aims to investigate the relationship between bile acid levels in intrahepatic cholestasis of pregnancy and adverse pregnancy outcomes such as preterm birth and stillbirth in twin pregnancies. Methods This retrospective single-center cohort study was conducted at the Second Hospital of Sichuan University from January 2014 to July 2022, focusing on twin pregnancies complicated by ICP. Patients were grouped based on peak levels of total bile acids during pregnancy. Differences among these groups in gestational weeks at delivery, preterm birth, fetal growth restriction, fetal distress, stillbirth, premature rupture of membranes, meconium-stained amniotic fluid, and newborn birth weight were observed as pregnancy outcome indicators. Results In 1156 twin pregnancies complicated by ICP, were 430 cases classified as mild, 392 as moderate-low, 292 as moderate-high, and 42 as severe. Regarding pregnancy outcomes, significant differences were observed among the four groups of pregnant women in terms of gestational weeks at delivery (P < 0.001), rate of preterm birth (P < 0.001), newborn birth weight (P < 0.001), incidence of meconium-stained amniotic fluid (P < 0.001), and proportion of low birth weight infants (P < 0.001). Conclusion The study results indicate that the severity of intrahepatic cholestasis of pregnancy (ICP) is associated with adverse pregnancy outcomes such as preterm birth, newborn birth weight, and meconium-stained amniotic fluid contamination. Additionally, among different bile acid level groups, gestational weeks at delivery showed varying trends in stillbirth occurrence.