Should Hepatitis B-positive mothers breastfeed?
I conclude the series on the importance of breastfeeding for August with an answer to an important question on whether Hepatitis B-positive mothers should breastfeed or not.
Taking cognisance of the immense benefits of breastfeeding, especially in our part of the world, mothers who are hepatitis B positive should still breastfeed, albeit with certain precautions.
Firstly, the benefits of breastfeeding far outweigh any potential risk of hepatitis B infection, especially in our subregion, where the cost of adequate use of alternatives to breastmilk is beyond the reach of most parents.
Secondly, it is recommended by the WHO guideline that for the prevention of mother-to-child transmission of hepatitis B, all infants should receive their first dose of hepatitis B vaccine as soon as possible after birth, preferably within 24 hours.
This dose of hepatitis B vaccine given at birth must be followed by two or three doses of hepatitis B vaccine at least four weeks apart to complete the primary series. Immunisation against hepatitis B starting at birth is the foundation of the prevention of perinatal and horizontal transmission of hepatitis B-exposed infants born to hepatitis B-positive mothers.
Thirdly, the WHO recommends that pregnant women testing positive for hepatitis B infection (HBsAg positive), with a Hepatitis B viral DNA above 200,000 IU/mL, or mothers who tested positive for HBeAg receive Tenofovir prophylaxis from the 28th week of pregnancy until birth, to prevent mother-to-child transmission of the hepatitis B virus – the so-called vertical transmission.
This drug targets the 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 immunoglobulin (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 of the hepatitis B virus to the baby through breastfeeding.
The rationale here is for the vaccine to encourage the baby's immune system to produce its own immunity against the hepatitis B virus (active immunity) while the hepatitis B immunoglobulin 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 the hepatitis B vaccine alone have been found to be highly effective in preventing transmission after exposure to the hepatitis B virus. The use of HBIG alone has also been shown to be effective in preventing hepatitis B virus transmission, but with the availability of the hepatitis B vaccine, HBIG is typically used as an adjunct to vaccination.
What determines the effectiveness of the post-exposure prophylactic measures is the early administration of the initial dose of vaccine. The longer it takes for the initiation of the post-exposure prophylaxis, the lower the effectiveness of the intervention. 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 the hepatitis B virus to be properly curtailed.
Post-exposure prophylaxis with hepatitis B vaccine and HBIG administered within 12 to 24 hours after birth, followed by the completion of a three-dose vaccine series, has been demonstrated to be up to 95 per cent effective in preventing acute and chronic hepatitis B virus infection in infants born to Hepatitis B-positive mothers. Studies have also demonstrated that HBIG, when administered as late as 72 hours after birth, is effective at curtailing the transmission of the virus.
It stands to reason, then, that all mothers must be tested for the hepatitis B virus during pregnancy and a plan made regarding post-exposure prophylaxis for those found to be positive.
Because it is a bit costly, mothers are encouraged to buy the combined vaccine and immunoglobulin (which is available on the market) before their due date, so the baby gets the vaccine and immunoglobulin right after birth.
The good news is that with the introduction of the pentavalent vaccine into our expanded programme of immunisation over 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 disappear with time.
I summarise all these long talks in the following points for easy recollection:
• Hepatitis B positive mothers with viral DNA above 200,000 copies or who are HBeAg positive should receive Tenofovir, an antiviral agent, to target viral replication from 24 weeks of pregnancy.
• All infants born to hepatitis B-positive women should receive the single-antigen hepatitis B vaccine (Engerix B) or 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 after birth.
• Post-vaccination testing for antibody to Hepatitis B surface antigen should be performed after completion of the vaccine series, at nine-18 months old. Testing should not be performed before nine months old, to avoid detection of antibody from HBIG administered during infancy and to maximise the likelihood of detecting late hepatitis B infection.
A special thanks to Maureen Kamischke for her reference materials.
The writer is a member of the Paediatric Society of Ghana and the Director of Medical Affairs, Korle Bu Teaching Hospital.
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