The effect of twin pregnancy in intrahepatic cholestasis of pregnancy: A case control study.

Abstract

Intrahepatic cholestasis of pregnancy (ICP) is one of the most common hepatic disorders during pregnancy, and the etiology is thought to be multifactorial including both environmental and hormonal contributions. In twin pregnancies, the fetal and placental mass is generally greater than in singleton pregnancies, and is, theoretically, likely to have a greater influence upon the maternal hepatic metabolism compared to singleton pregnancy. The aim of this study was to compare ICP in twin and singleton pregnancies according to ICP characteristics, time of diagnosis, serum bile acid levels, pharmacological treatment, and pregnancy outcomes. This case control study was undertaken at Aarhus University Hospital, Denmark, from 2012 to 2019. The study comprised 51 women with twin pregnancies and ICP. These women were matched with 153 women with twin pregnancies without ICP and 153 women with singleton pregnancies with ICP, respectively. Three controls were matched per case, and data obtained from medical records and Danish obstetrical databases were compared. We found a significantly lower gestational age at ICP diagnosis in twin pregnancies (227 vs. 242 days for singleton pregnancies; p = 0.002). Bile acids reached significantly higher maximum blood levels in twin pregnancies (32.9 vs. 22.2 μmol/L; p = 0.012), and at a lower gestational age (gestational age maximum bile acids: 235 vs. 250 days; p < 0.001). No difference in pharmacological treatment was observed between the groups. Twin pregnancies with and without ICP had comparable pregnancy outcomes; however, ICP pregnancies had a higher incidence of gestational diabetes mellitus (15.7% vs. 5.2%; p = 0.03). In repeat pregnancies, ICP was diagnosed earlier in the twin pregnancy (p = 0.006). Compared to singleton pregnancies, twin pregnant women with ICP have an earlier diagnosis of ICP, and levels of bile acids are higher. Compared to twin pregnancies without ICP, the pregnancy outcomes are comparable.