Source Clinical Ethics Advisory Group, Children's Hospital at Westmead, Westmead, NSW, 2145, Australia; University of Sydney, NSW, 2006, Australia.

Without intervention, a pregnant woman who is a chronic hepatitis B carrier is at risk of transmitting hepatitis B and of her infant becoming a chronic carrier and having a significantly increased lifetime risk of developing liver cancer or cirrhosis. Hepatitis B vaccine and immunoglobulin reduce the risk of the baby becoming a carrier, but with only a short window period after birth to deliver this potentially life-saving intervention. We reviewed the evidence on the magnitude of the risk. If the carrier mother is e antigen positive (highly infective), the calculated risk to the infant without intervention is 75.2%, reduced to 6.0% by giving vaccine and immunoglobulin at birth. If the mother is surface antigen positive but e antigen negative, the risk to the infant without intervention is 10.3%, reduced to 1.0% by giving vaccine and immunoglobulin. If vaccine is accepted but immunoglobulin refused, as for example by some Jehovah's Witnesses, the risk to babies of e antigen positive mothers is reduced to 21.0% and to babies of e antigen negative mothers to 2.6%. These figures can be used to inform parents and as a possible basis for child protection proceedings if parents decline vaccine and/or immunoglobulin. We argue from the perspective of the best interests of the child that the severity of the condition justifies initiating child protection proceedings whenever a baby is born to a hepatitis B carrier mother and, despite concerted attempts to persuade them, the parents refuse vaccine and/or immunoglobulin.