OBJECTIVE To explore the risk factors for intrauterine hepatitis B virus (HBV) infection in the pregnant women carried with HBV and analyze the association with gene polymorphisms of interleukin-28B (IL-28B).

METHODS A total of 620 HBsAg-positive pregnant women who were treated in Jinan Second Maternal and Child Health Hospital from Jan 2019 to Feb 2022 were recruited as the research subjects, 50 of whom had intrauterine HBV infection and were assigned as the infection group, and 570 who did not have intrauterine infection and were assigned as the no infection group. The polymorphisms at rs8099917 locus of IL-28B gene were statistically analyzed, and the risk factors for the intrauterine HBV infection were observed.

RESULTS The frequencies of GG genotype and G allele of the infection group were significantly higher than those of the no infection group(P < 0.05). The risk factors for the intrauterine HBV infection in the HBsAg-positive pregnant women included the GG genotype and G allele of IL28 gene, HBV DNA more than 10⁶ copies/ml, change of liver B-ultrasound and positive pre S1 protein(P < 0.05).

CONCLUSION The intrauterine HBV infection of the HBsAg-positive pregnant women is associated with the IL-28B gene polymorphisms, HBV DNA level, change of liver B-ultrasound and positive pre S1 protein.