[Mother-to-child transmission of hepatitis B virus despite postexposure prophylaxis: A review of the literature and description of 11 observations].

Chronic hepatitis B virus (HBV) infection leads to a risk of developing cirrhosis and hepatocellular carcinoma. In France, where the prevalence of HBV is low, mother-to-child transmission is the cause of chronic infection in more than one-third of cases. After exposure, the risk of chronic infection is the highest for newborns (90 %). The World Health Organization implemented a global immunization program in 1991, applied in France in 1994. A significant number of children are infected each year, however, and failure of postexposure prophylaxis is reported in 4-10 % of newborns. We report 11 children with chronic HBV infection due to failure of serovaccination, followed up in two centers between 1993 and 2015. We discuss maternal screening, serovaccination, and follow-up conditions, as well as the role of maternal viral load, amniocentesis, and mode of delivery as risk factors. These observations confirm that serovaccination failures are related to the nonobservance of recommendations for maternal screening or postexposure prophylaxis, and to a high maternal viral load (>10 copies/mL). We therefore recommend improving the screening strategy, with control of the hepatitis B antigen in early pregnancy, and discussion of treatment with a nucleoside analog during the last trimester of pregnancy. Serovaccination should be enforced. Its efficacy should be controlled when the child reaches 9 months of age, in order to organize the follow-up if infection occurs.