How is hepatitis B transmitted to the baby, and how is it prevented?

Hepatitis B is commonly transmitted vertically (mother to baby), mainly around the time of delivery, and infection acquired at birth often becomes chronic (risk of cirrhosis/hepatocellular carcinoma).

Prevention: antenatal hepatitis B screening, and giving the newborn the hepatitis B vaccine (+ hepatitis B immunoglobulin if the mother is positive) at birth - effectively preventing transmission.

Clinical relevance. Knowing hepatitis B vertical transmission and its prevention (screening, birth-dose vaccine + HBIG) prevents chronic infection and its long-term liver complications.

More Detail

Hepatitis B transmission to the baby and its prevention

Hepatitis B is an important vertically transmitted, vaccine-preventable infection.

Transmission

• Vertical transmission (mother to baby) - mainly around the time of delivery (perinatal); also possible in utero.
• Infection acquired at birth or in early life frequently becomes chronic (the younger the age at infection, the higher the chronicity rate).

Consequences

• Chronic hepatitis B -> cirrhosis and hepatocellular carcinoma in later life.

Prevention

• Routine antenatal screening for hepatitis B (HBsAg).
• Give the newborn the hepatitis B vaccine at birth (and complete the course).
• Add hepatitis B immunoglobulin (HBIG) to the newborn if the mother is HBsAg-positive (especially HBeAg-positive).
• Maternal antiviral therapy if the viral load is high.

Outcome

• Birth-dose vaccination (+/- HBIG) is highly effective at preventing vertical transmission.