Current status of hepatitis B virus infection among pregnant women in Shaanxi Province, China and risk factors for mother-to-infant transmission

Objective To investigate the hepatitis B virus ( HBV) infection rate among pregnant women in Shaanxi Province, China and the high-risk population of mother-to-infant transmission ( MTIT) . Methods A survey was performed for 13 451 pregnant women in 18 hospitals in Shaanxi Province to investigate the status of HBV infection, and combined immunization was performed for the infants born to HBsAg-positive women. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for MTIT. The t-test or the Mann-Whitney U test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. Results The prevalence rate of HBsAg was 7. 07% among the pregnant women in Shaanxi Province, and the rate reached as high as 9. 40% in southern Shaanxi. The MTIT rate of HBV was 5. 21%. The univariate analysis showed that HBsAg titer, HBeAg titer, positive HBeAg, and HBV DNA load in mothers were associated with HBV infection in infants, and the multivariate analysis showed that HBV DNA load in mothers is an independent risk factor for MTIT ( relative risk = 1. 586, 95% confidence interval: 1. 020-2. 465, P = 0. 041) . Among the pregnant women with HBV infection and MTIT, 84. 62% had positive HBe Ag and an HBV DNA load of > 106 IU/ml; among the infants with MTIT, 15. 38% were the infants born to the HBe Ag-negative pregnant women. For the pregnant women with positive HBe Ag and HBV DNA > 106 IU/ml, the relative risk of MTIT in infants was 1. 210 ( 1. 129-1. 297) ; for the pregnant women with negative HBe Ag, HBV DNA > 2 × 103 IU/ml, and HBs Ag > 104 IU/ml, the relative risk of MTIT in infants was 26. 062 ( 2. 633-258. 024) . Conclusion There is a high HBV infection rate among pregnant women in Shaanxi Province. Pregnant women with positive HBeAg and a high HBV DNA load have a high risk of MTIT. Although the infants born to HBeAg-negative mothers have a low HBV infection rate, there is still a high risk of MTIT when the mother has an HBV DNA load of > 2 × 103 IU/ml and an HBsAg level of > 104 IU/ml.