Mothers who are hepatitis B positive should still breastfeed but with certain conditions attached.
First, the benefits of breastfeeding far outweighs any potential risk of infection of hepatitis B infection, especially in our part of the world where the cost of alternatives to breastmilk is prohibitive to most parents.
Second, it is recommended by the WHO guideline recommendation for prevention of mother-to-child transmission of hepatitis B that all infants receive their first dose of hepatitis B vaccine as soon as possible after birth, preferably within 24 hours and that the birth dose be followed by two or three doses of hepatitis B vaccine at least four weeks apart to complete the primary series.
Third, the WHO recommends that pregnant women testing positive for hepatitis B infection (HBsAg positive) with an HBV DNA above 200,000 IU/mL or who tested positive for HBeAg receive tenofovir prophylaxis from the 28th week of pregnancy until at least birth, to prevent mother-to-child transmission of hepatitis B virus. This drug targets replication of the virus and thus reduces the number of viral particles and the chance of viral transmission to the baby.
Lastly, there are post-exposure measures that if adhered to, can further reduce the potential risk of transmission through breastmilk. This involves concurrent injection of hepatitis B vaccine and hepatitis B immunoglobin (HBIG) to a baby born to a mother with hepatitis B soon after birth.
This added measure helps to reduce to the barest minimum any chance of transmission to the baby through breastfeeding. The rational here is for the vaccine to enable the baby’s immune system to produce its own immunity against the hepatitis B virus (hence called active immunity), while the hepatitis B immunoglobin helps to mop up any viruses floating in the bloodstream (Passive immunity).
Both passive and active post-exposure prophylaxis with HBIG and hepatitis B vaccine and active post-exposure prophylaxis with hepatitis B vaccine alone have been demonstrated to be highly effective in preventing transmission after exposure to hepatitis B virus.
The use of HBIG alone has also been demonstrated to be effective in preventing hepatitis B virus transmission but with the availability of hepatitis B vaccine, HBIG typically is used as an adjunct to vaccination.
What determines how effective the post-exposure prophylactic measures would be is early administration of the initial dose of vaccine? The effectiveness diminishes the longer it is initiated after exposure.
Studies are limited on the maximum interval after exposure during which post-exposure prophylaxis is effective, but the interval should not exceed seven days for mother to child transmission of hepatitis B virus.
Post-exposure prophylaxis with hepatitis B vaccine and HBIG administered 12 to 24 hours after birth, followed by completion of a three-dose vaccine series, has been demonstrated to be 85 to 95 per cent effective in preventing acute and chronic hepatitis B virus infection in infants born to women who are hepatitis B positive.
Studies have also demonstrated that the HBIG, when administered as late as 72 hours of birth, is effective at curtailing the transmission of the virus.It stands to reason then that all mothers must be tested for hepatitis B virus during pregnancy and a plan made regarding post-exposure prophylaxis for those found to be positive.
This is because it is a bit costly, mothers are encouraged to buy the combined vaccine and immunoglobin (which is available on the market) before their due date so the baby gets the vaccine and immunoglobin right after birth.
The good news is that with the introduction of the pentavalent into our expanded programme of immunisation 20 years ago, the number of mothers who would be positive for Hepatitis B is dwindling so hopefully, hepatitis B transmission to the baby may be disappear with time.
The summary points to remember are:
• Hepatitis B positive mothers with viral DNA above 200,000 copies or are HBeAg positive should receive tenofovir to target viral replication from 24 weeks of pregnancy.
• All infants born to hepatitis B-positive women should receive single-antigen hepatitis B vaccine or with HBIG less than 12 hours of birth, administered at different injection sites. The vaccine series should be completed according to a recommended schedule for infants and in Ghana that is 6, 10 and 14 weeks.
• Post-vaccination testing for antibody to hepatitis B surface antigen testing should be performed after completion of the vaccine series, at age nine to 18 months. Testing should not be performed before age nine months to avoid detection of antibody from HBIG administered during infancy and to maximise the likelihood of detecting late hepatitis B infection.
• Infants of HBsAg-positive mothers can be breastfed beginning immediately after birth once the post-exposure prophylactic measures are observed.
The other option which is not highly recommended because of the exceeding benefits of breastfeeding is resorting to exclusive formula feeding of the baby. This comes with its own problems of cost, poor preparation and storage of the milk, diarrhoea etc, with exclusive formula feeding though, the risk of transmission of hepatitis B through breastfeeding is eliminated.
A special thanks to Maureen Kamischke for her reference materials.
A member of Paediatric Society of Ghana