ObjectiveTo explore the influence of paternal serum HBV-DNA load levels and pregnant women's HBsAb on vertical transmission of hepatitis B virus (HBV) from HBsAg positive fathers to infants in order to provide effective methods for paternal-fetal ventrical transmission of HBV prevention. MethodsUsing HBsAg and HBV-DNA as indicators to screen pregnant women and their husbands after gained consent, 121 families with HBVM negative or only HBsAb positive and HBV-DNA negative pregnant women, HBsAg positive husbands and their newborns were selected. In this case-control study, according to neonatal cord blood HBV-DNA detection, 23 newborns with cord blood HBV-DNA positive were selected as cases, 98 newborns as controls. ResultsThe positive rate of neonatal cord blood HBV-DNA was 19.0% (23/121); and there was dose-response relationship between paternal serum HBV-DNA load levels and neonatal cord blood HBV-DNA positive (trend χ2=60.108, P=0.000). The analysis of ROC curve showed that paternal serum HBV-DNA load level (106 copies/mL) is a better demarcation point to forecast the occurrence of vertical transmission of HBV from HBsAg positive fathers to infants, because there was a better sensitivity and specificity during forecast; and HBsAb negative pregnant women's were statistically significant (χ2=12.399, P=0.000). There was no significant difference at the positive rate of neonatal cord blood HBV-DNA between the case group and control group when paternal serum HBV-DNA load levels exceed 107 copies/mL (P > 0.05). ConclusionPaternal serum HBV-DNA load levels and HBsAb negative pregnant women are the risk factors of vertical transmission of HBV from HBsAg positive father to infants. Paternal serum HBV-DNA load level (106 copies/mL) is an appropriate index of the occurrence of vertical transmission.