SUPERStudy: Perinatal Transmission of Hepatitis B

By usmlevideoss

Overview

Perinatal transmission of hepatitis B virus (HBV) occurs when an HBV-infected mother passes the virus to her baby during childbirth. This is the most common mode of transmission in high-prevalence regions.

  • Without intervention: Up to 90% of infants born to mothers with active HBV infection will become infected, with most developing chronic HBV.

Key Points

1. Risk Factors

  • Maternal HBeAg positivity is the strongest predictor:
    • 70–90% risk of neonatal infection.
    • 80–90% of children born to mothers positive for both HBsAg and HBeAg will become infected, and 90% of those infants will develop chronic HBV.
    • Transmission risk:
      • <25% if HBeAg-negative.
      • 12% if anti-HBe is present.
  • High maternal HBV DNA levels significantly increase transmission risk.

2. Timing of Transmission

  • Primary route: Neonatal exposure to maternal blood at delivery.
  • Intrauterine infection: Rare (<5–10%), but possible with extremely high maternal HBV DNA levels or placental damage.
  • HBV in body fluids: Present, including in breast milk, but transmission via breastfeeding is rare.

3. Prevention

  • Hepatitis B Immunoglobulin (HBIG) and Vaccine:
    • Administer HBIG and the first HBV vaccine dose within 12 hours of birth to reduce transmission risk by 90–95%.
    • HBIG can be given as late as 7 days postpartum if the vaccine is also administered.
    • Complete HBV vaccine series (at 0, 1, and 6 months) ensures long-term protection.
  • Universal HBV immunization: Recommended for all infants at birth, regardless of maternal HBV status.
  • Antiviral therapy: For mothers with high viral loads (>200,000 IU/mL), tenofovir during the third trimester reduces transmission risk.

4. Breastfeeding

  • Safe if the newborn receives appropriate immunoprophylaxis (HBIG and vaccine).
  • HBV is not transmitted through breast milk.

5. Follow-Up

  • Infants should be tested for HBsAg and anti-HBs at 9–12 months to:
    • Confirm immunity.
    • Rule out infection.

SUPERPoint

Timely immunoprophylaxis with HBIG and the HBV vaccine is highly effective in preventing perinatal HBV transmission, even in high-risk cases.

References: 

Sokol RJ, Boster JM, Feldman AG, Mark JA, Mack CL, Sundaram SS. Liver & Pancreas. In: Bunik M, Levin MJ, Abzug MJ, Schreiner TL. eds. Current Diagnosis & Treatment: Pediatrics, 27th Edition. 

Raab EL, Kelly LK. Neonatal Resuscitation. In: DeCherney AH, Nathan L, Laufer N, Roman AS. eds. CURRENT Diagnosis & Treatment: Obstetrics & Gynecology, 12e. McGraw-Hill Education; 2019