Abstract: Objective To analyze the correlation between expression of placental abcb4 gene and prognosis of perinatal infants in patients with intrahepatic cholestasis of pregnancy (ICP). Methods Sixty cases of ICP pregnant women who were regularly given production inspection in our hospital from May, 2015 to May, 2017 were set as ICP group, including 36 cases of mild ICP and 24 cases of severe ICP. Another 30 cases of pregnant women with normal checkups were selected as control group. The expressions levels of abcb4 mRNA and abcb4 protein in placenta were determined by RT-PCR and immunohistochemistry, and their relationship with amniotic fluid contamination, neonatal Apgar score and poor prognosis were analyzed. Results Compared with control group, the amniotic fluid contamination rate was significantly higher in ICP group while the neonatal Apgar score was significantly lower, and the incidence rates of premature delivery, neonatal asphyxia and low birth weight infants were significantly higher (P<0.05). There were statistically significant differences in the amniotic fluid contamination rate, neonatal Apgar score, incidence rates of premature delivery and neonatal asphyxia between mild ICP patients and severe ICP patients (P<0.05). Compared with control group, the abcb4 mRNA level in ICP group was significantly decreased, and the abcb4 protein expression intensity was significantly decreased (P<0.05). Compared with mild ICP patients, the abcb4 mRNA level was significantly decreased in severe ICP patients, and the abcb4 protein expression intensity was significantly decreased (P<0.05). Pearson correlation analysis showed that abcb4 mRNA level and abcb4 protein expression intensity in placenta of ICP patients were negatively correlated with amniotic fluid contamination rate, Apgar score and incidence rates of premature delivery and neonatal asphyxia (P<0.05). Conclusion The expression level of abcb4 gene in placenta of ICP patients is closely related to the prognosis of perinatal infants. Especially the decrease of abcb4 gene expression level can increase the risk of amniotic fluid contamination, premature delivery and neonatal asphyxia.