Lack of evidence for transplacental transmission of HBV infection by HBsAg-carrier mothers

Abstract

The possibility of transplacental transmission of HBV infection was investigated in 54 HBsAg-carrier Saudi mothers and their newborns. Controls were 60 Saudi mothers with previous exposure to HBV, and their newborns. Thirteen cord blood samples were HBsAg-positive by ELISA, including three from mothers with previous exposure to HBV, compared with one sample which was HBsAg- and HBeAg-positive and three samples which were only HBeAg-positive. Eight of the 13 cord blood samples which were HBsAg-positive by ELISA were haemolysed sera and were found to be HBsAg-negative by RIA and RPHA. None of the infants' sera, taken within 1-4 days of delivery, was positive for HBsAg or IgM anti-HBc. These results indicate that HBV markers in cord blood are either false-positive or due to contamination by maternal blood rather than an indication of in utero infection.