Vertical Transmission of Hepatitis B Antigen in Taiwan

Abstract

To determine the frequency of vertical transmission of hepatitis B antigen (HB_s Ag) from asymptomatic carrier mothers in Taiwan to their offspring, HB_s Ag was sought by radioimmunoassay and complement fixation. Of 158 babies born to carrier mothers, antigenemia developed in 63; 51 of these antigenemic babies had become antigen positive within the first six months of life. Three inter-related factors were found to increase the risk that antigenemia would develop in the infant: a high maternal complement-fixation titer for HB_s Ag: presence of HB_s Ag in the baby's umbilical-cord blood: and antigenemia in siblings. In contrast to previous studies, these findings indicate that vertical transmission from carrier mothers frequently occurs, at least in Taiwan, and may partially explain Taiwan's high prevalence of HB_s Ag. (N Engl J Med 292:771–774, 1975)