The Traditional Approach
The current standard of care for the prevention of transmission of HBV from an infected mother to her infant in developed countries is based on passive-active prophylaxis -- that is, intramuscular injection of HBIg immediately after birth (ideally in the first few hours), combined with active immunization brought about with the HBV vaccine series beginning at birth with subsequent doses given at 1 and 6 months of age.[2,5,9,10,11,12] The HBIg is administered at a different site from the first dose of HBV vaccine. The infant is then tested for HBsAg and anti-HBs 1-2 months after completing the vaccine series to confirm immunity and to rule out infection.
When optimally applied, this strategy of care will successfully reduce the rate of mother-to-child HBV transmission from > 90% to < 10%. However, failure to recognize the HBsAg-positive mother or nonadherence with the recommended strategy will allow perinatal transmission of HBV infection.
This strategy depends on coordination of care of pregnant women, beginning with the first prenatal visit. All pregnant women should be tested for HBV infection. The care team responsible for perinatal care of the infant must be alerted to the maternal HBV infection status to implement the prophylaxis regimen.[1,11,15]
What Is the Success of This Approach?
Prenatal HBV screening followed by postnatal passive-active immunoprophylaxis within 24 hours of birth is highly effective in preventing perinatal transmission of HBV.[1,11,16] The long-term efficacy of postnatal vaccination and HBIg administration in high-risk patients was explored by Wu and colleagues. In 8733 senior high school students who were born after July 1987, the overall rates of HBsAg and anti-HBs positivity were 2% and 48%, respectively. Maternal HBeAg positivity was the most important determinant of HBsAg positivity in adolescents who had received postnatal immunoprophylaxis 15 years earlier.
In another recent study of infants born to 3253 HBV-positive mothers, the infant infection rate was 0.75 per 100 births. Rates per 100 births were 3.4 for HBeAg-positive mothers and 0.04 for HBeAg-negative mothers. Similarly, infection rates per 100 births were 3.6 among births to mothers with high viral loads (HBV DNA level > 108 copies/mL) and zero among births to mothers with lower viral loads, regardless of HBeAg status. These studies identify a subset of HBV-infected women in whom additional preventive measures, such as administration of antiviral agents during the third trimester, may be required.
Medscape Gastroenterology © 2015 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: William F. Balistreri. Perinatal Transmission of the Hepatitis B Virus - Medscape - Jun 04, 2015.