The impact of intrahepatic cholestasis on pregnancy outcomes: a retrospective cohort study

BACKGROUND: This study analyzed the pregnancy outcomes of patients with intrahepatic cholestasis of pregnancy (ICP) in Hangzhou, China. METHODS: Cases of pregnant women monitored by antepartum testing at Hangzhou Women’s Hospital from January 2018 to December 2020 were reviewed. Subjects were classified into two groups according to whether they had ICP: 688 cases of ICP were assigned to an exposure group while 38,556 cases of non-ICP were assigned to a non-exposed group. Univariate analysis was performed on qualitative or quantitative data using the Chi-Squared test or Mann–Whitney U test, and the adjusted odds ratio (aOR) and 95% confidence interval (CI) of the two groups of related variables were calculated by multivariate binary logistic regression analysis. RESULTS: The incidence rate of ICP was 1.75%. Pregnant women with hepatitis B virus were correlated with ICP. Hepatitis B carriers (aOR = 3.873), preeclampsia (PE, aOR = 3.712), thrombocytopenia (aOR = 1.992), gestational hypertension (GH, aOR = 1.627), hyperlipidemia (aOR = 1.602) and gestational diabetes mellitus (GDM, aOR = 1.265) were all risk factors for ICP. In contrast, Body Mass Index (BMI) ≥ 30 kg/m(2) (aOR = 0.446), 25 m(2) < maternal BMI < 29.9 kg/m(2) (aOR = 0.699) and parity ≥ 1 (aOR = 0.722) were protective factors for ICP. Pregnant women in the ICP group had an increased risk of gestation days < 259 days (aOR = 4.574) and cesarean delivery (aOR = 1.930) after ICP, and a decreased risk of longer gestational days (aOR = 0.105), premature rupture of membranes (aOR = 0.384) and fetal macrosomia (aOR = 0.551). CONCLUSIONS: By analyzing a Chinese population with ICP, we identified that pregnant women who are hepatitis B carriers or with PE, thrombocytopenia, GH, hyperlipidemia, and GDM are at higher risk of ICP. Moreover, ICP is associated with adverse pregnancy outcomes; in particular, ICP may increase the incidence of shorter gestational days and non-vaginal delivery methods such as cesarean section but reduce the incidence of premature rupture of membranes and fetal macrosomia. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12876-023-02652-3.