Hepatitis B virus (HBV) infection is a worldwide public health crisis, both acutely and from sequelae in chronically infected individuals. Transmission occurs via vertical transmission or early childhood infection in the countries where HBV endemic. Strategies to decrease the risk include prevention of blood and body fluids exposure, avoidance of high-risk behaviors, universal screening of women during pregnancy and active and passive immunization. Hepatitis B vaccine has been shown to be safe and effective for pregnant women, but still not given in pregnant women and high-risk patients.
Perinatal transmission of HBV occurs if the mother has had acute HBV infection during late pregnancy or in the first month post-partum or if the mother is a chronic HBV antigen carrier. Vertical transmission from chronic carrier exceeds 90% and exceeds up to 40% of the world chronic carriers in endemic areas. 60% of the pregnant women who acquire acute HBV infection at or near delivery will transmit the HBV to their offspring. Although infection is rarely symptomatic, 70 to 90% of the babies will remain chronically infected into the adult life and prone to cirrhosis and hepatocellular carcinoma. Because of high risks and the safety and efficacy of HB vaccine in preventing HB infection, it is recommended that HB vaccine is given to pregnant women at high risk. However, its safety to the fetus is not well documented.
Pregnant women who are at high risk of HBV infection during pregnancy (more than one sex partner during the previous six months, been evaluated or treated for STD, recent or current injection for drug use, or having HBsAg positive sex partner) should be vaccinated. No congenital anomaly was observed in infants. All infants were physically and developmentally normal.
The risk to the developing fetus from the vaccination of the mother during pregnancy is theoretical. Available vaccines contain noninfectious HBsAg and should cause no risk of infection to the fetus. So HB vaccine should be provided to all pregnant women at risk for disease acquisition during pregnancy.