Abstract: Objective To investigate the effects of serum bile acid levels on pregnancy and perinatal outcomes in women with intrahepatic cholestasis of pregnancy (ICP) with different times of disease onset. Methods Clinical data of pregnant women with ICP from January 2022 to December 2025 in Yangzhou Maternal and Child Health Care Hospital Affiliated to Yangzhou University were collected, including a total of 115 cases. According to the gestational age at onset, patients were classified as early-onset or late-onset ICP, and further stratified into mild or severe ICP based on serum total bile acid (TBA) levels. The patients were ultimately divided into four groups: early-onset mild (n=15), early-onset severe (n=10), late-onset mild (n=62), and late-onset severe (n=28). General clinical characteristics, laboratory parameters, pregnancy outcomes, and perinatal outcomes were compared among the groups. Results The results showed that there were no significant differences among the four groups in maternal age or pre-pregnancy body mass index (P>0.05). The gestational age at diagnosis was significantly earlier in women with early-onset ICP than in those with late-onset ICP [(24.6±2.1) weeks vs. (33.8±2.6) weeks, P<0.05)]. Serum TBA levels were significantly higher in women with severe ICP than in those with mild ICP [early-onset: (82.4±21.6) μmol/L vs. (24.6±7.8) μmol/L; late-onset: (76.3±18.9) μmol/L vs. (22.9±6.5) μmol/L; all P<0.05]. Regarding pregnancy outcomes, the early-onset severe ICP group had the highest rates of cesarean delivery and preterm birth, at 80.0% and 70.0%, respectively, which were significantly higher than those in the early-onset mild group (40.0% and 26.7%), late-onset mild group (35.5% and 14.5%), and late-onset severe group (60.7% and 39.3%) (P<0.05). Analysis of perinatal outcomes showed that neonates in the early-onset severe ICP group had the lowest gestational age at birth (33.4±2.6) weeks and birth weight (1980±510) g. This group also exhibited the highest incidences of low birth weight (60.0%), fetal distress (50.0%), neonatal intensive care unit admission (70.0%), and neonatal asphyxia (30.0%), all of which were significantly higher than those in the other three groups (P<0.05). Conclusion Serum bile acid levels are closely associated with the severity of liver dysfunction, pregnancy outcomes, and perinatal prognosis in women with ICP. Early-onset severe ICP represents the highest-risk subtype for adverse maternal and fetal outcomes and warrants intensified prenatal surveillance and individualized management.

Key words: Intrahepatic cholestasis of pregnancy, Total bile acids, Early-onset ICP