Evidence against breast-feeding as a mechanism for vertical transmission of hepatitis B.

A follow-up study of 147 babies born to mothers known to be carriers of hepatitis B surface antigen (HBsAg) revealed no evidence for a relationship between breast-feeding and the subsequent development of antigenaemia in the babies. All babies were tested at three or more months of age, and the mean age at last follow-up was eleven months with a mean of three serum specimens per baby (not counting cord-blood specimens). The frequency of acquisition of HBsAg and anti-HBs was almost identical among breast-fed and non breast-fed infants. The frequency of other variables known to influence the development of antigenaemia among infants of carrier mothers did not vary according to breast-feeding status: mother's HBsAg titre, HBsAg positivity rate in cord-blood specimens, and HBsAg prevalence among siblings. 32 breast-milk specimens from carrier mothers were all HBsAg negative.