Risk factors for intrauterine infection with hepatitis B virus

ObjectiveTo investigate risk factors for hepatitis B virus (HBV) intrauterine infection.MethodsPeripheral blood samples and clinical data were collected from 174 pregnant women who were positive for hepatitis B surface antigen (HBsAg). Their 176 neonates received an active–passive immunization schedule at 0, 1, and 6 months. Blood samples from the infants, collected before immune prophylaxis administration, were tested for HBV markers and HBV DNA.ResultsThe intrauterine infection rate at 6 months after birth was 5.1%. Maternal HBV DNA positivity (OR 11.362; 95% CI, 1.389–92.931), hepatitis B e antigen (HBeAg) positivity (OR 7.278; 95% CI, 1.734–30.538), and thalassemia minor (OR 15.619; 95% CI, 2.239–108.964) were associated with intrauterine infection. The intrauterine infection rate for mothers with 105 copies/mL of serum HBV DNA or more was 18.2%, compared with 0.8% for mothers with less than 105 copies/mL.ConclusionA positive HBsAg test at 24 hours and/or 1 month of age followed by a positive test at 6 months is an objective and comprehensive criterion for the diagnosis of HBV intrauterine infection. Maternal HBV DNA positivity (especially 105 copies/mL of HBV DNA or more), HBeAg positivity, and thalassemia minor are risk factors for HBV intrauterine infection.