Abstract
Vertical transmission of hepatitis B virus (HBV) has been proposed to play an important role in mother-to-child transmission, although the extent to which vertical transmission via oocytes contributes to neonatal HBV infection remains unknown. Ovarian biopsies were collected during caesarean sections in 68 clinically asymptomatic pregnant women who were carriers of HBV. The presence of hepatitis B surface antigen (HBsAg) in the ova of pregnant women was determined by immunohistochemistry. Serum markers of HBV infection in pregnant women and their neonates were analysed. It was found that, of 68 women, the ova were positive for HBsAg in only one woman and her neonate was negative for any serum HBV markers 3 days after birth. Of 68 neonates, one was positive for serum HBV markers 3 days after birth and his mother's ova were negative for HBsAg. These findings indicate that vertical transmission via oocytes may not be the major route of HBV intra-uterine infection.