Hepatitis B virus infection in pregnant mothers and its transmission to infants.

Screening for serological markers of hepatitis B virus infection was done on 500 pregnant mothers. HBsAg, AntiHBs and HBeAg were done. HBsAg was positive in 3.6%, AntiHBs in 17.4% and HBeAg in 0.4% cases. The infants born to the asymptomatic HBsAg carrier mothers were followed up to 6 months to determine the vertical transmission of HBV infection. Rate of transmission of infection from HBsAg positive mothers to infants were 16.66% irrespective of HBeAg status, whereas it was nearly 100% in case of HBeAg positive mothers. All of the HBsAg positive infants developed the antigenemia between 3-6 months of age, supporting the hypothesis that intrapartum transmission is the major mode of vertical transmission.