Centre for Evaluation of Vaccination (CEV)
Perinatal transmission is one of the most efficient and devastating modes of transmitting hepatitis B virus because 60 to 90% of infected new-borns become chronic carriers of the virus. The main objective of maternal screening is to identify HB carrier women and to prevent hepatitis B carriage in their infants; this can be achieved by screening all pregnant women for HBsAg and vaccinating new-borns of carrier mothers. Control of perinatal transmission can also be achieved by universal new-born vaccination starting at birth.
Where screening of pregnant women for HBsAg exist, countries may wish to continue screening programmes. If this is the case, any screening programme should include all pregnant women, as selective screening of pregnant women (focused on risk groups) misses a significant proportion of carrier mothers. Screening for HBsAg should be part of routine antenatal care.
Women who present for delivery without having been screened for HBsAg should be tested immediately. Their new-borns should be vaccinated within 12 hours of birth, irrespective of the results of the screening test.
Most industrial countries have carried out universal screening of pregnant women for many years.
Most countries currently administer HBIg and vaccine to infants of carrier mothers, although recent evidence suggests that vaccine alone may be just as effective. Vaccine should be given within 12 hours of birth. In cases where HBIg is given, it should be administered within 12 hours of birth at another injection site than the vaccine. The schedules most widely used are 0,1,6 and 0,1,2,12 months, both of which have shown to be effective.
Effective programmes for the prevention of perinatal transmission require transfer of information to the mother, and among the antenatal care centre, the delivery unit and the infant immunisation provider. An organisational framework should be in place, and responsibility for co-ordination of HBsAg screening and follow-up of vaccination of new-borns should be well defined. Countries should systematically monitor and evaluate prevention programmes.
Where maternal screening programmes do not exist, resources may be better directed towards universal neonatal immunisation programmes. Control of perinatal transmission can be achieved if the first dose of vaccine is delivered at birth.
HBsAg-positive mothers should not be discouraged from breast-feeding.