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Maternal Transmission of Hepatitis B


Babies are at high risk of infection during delivery

In Hong Kong, the prevalence of hepatitis B virus (HBV) infection in antenatal women is 4% in 2019.
HBV can be transmitted from infected mothers to their babies during vaginal delivery or Caesarean section. Without any preventive measures, 90% of babies exposed to HBV at birth would develop chronic hepatitis B (CHB) infection.

ALL pregnant women should know their hepatitis B status. If no preventive measures are taken, your baby has a more than 90% chance of developing chronic hepatitis B.

It is important for pregnant women to have blood test for hepatitis B during pregnancy, as proper interventions can be taken for HBV-infected pregnant women to prevent transmission of HBV to their newborn babies.

Protect Babies from Infection

Hepatitis B Vaccine

In Hong Kong, universal neonatal hepatitis B vaccination programme was implemented in 1988. All newborns would receive the first dose of the vaccination in the hospital and the second and third doses at 1 month and 6 months of age in the Maternal & Child Health Centres, Department of Health.

Hepatitis B vaccine is very safe and effective in preventing HBV infection.
The complete course of hepatitis B vaccination takes a total of three injections. After a complete course of hepatitis B vaccination, 90 to 95% of babies would produce protective antibody levels, which can confer long-term protection against HBV infection.

Hepatitis B immunoglobulin

For immediate extra protection, babies born to HBV-infected mothers would also receive an additional dose of hepatitis B immunoglobulin (HBIG) within 24 hours after birth.

Antiviral medication

If the pregnant women are tested positive for HBV, doctor may perform blood tests, such as liver function tests, and blood level of virus (HBV DNA), to guide clinical management during pregnancy.

If the HBV DNA level of pregnant women is high, doctor may recommend the use of oral antiviral medication in the third trimester, which is safe and can reduce HBV viral level in their blood and reduce the chance of HBV transmission to their babies.

Consult the doctor for the appropriateness of using antiviral medication.