Management of Hepatitis B in Pregnancy
All pregnant women with chronic HBV infection and HBV DNA >200,000 IU/mL (or HBeAg-positive status) should receive tenofovir disoproxil fumarate starting at 24-28 weeks of gestation and continuing through 12 weeks postpartum to prevent mother-to-child transmission. 1
Screening Protocol
- Screen all pregnant women for HBsAg in the first trimester to identify those at risk for vertical transmission 1, 2
- Measure HBV DNA and ALT levels at 26-28 weeks gestation in all HBsAg-positive women to determine antiviral prophylaxis needs 1, 2
- Monitor HBV DNA and ALT every 12 weeks during pregnancy and at 4-6 weeks postpartum, as hepatitis B may flare due to immunologic changes 1
Antiviral Therapy: Who, When, and What
Indications for Treatment
High viral load mothers (HBV DNA >200,000 IU/mL or >10^6 IU/mL) should receive antiviral prophylaxis starting at week 24-28 of gestation 1. This threshold is critical because even with standard immunoprophylaxis (HBIG + vaccine), 4-10% of infants born to highly viremic mothers still become infected 1.
Women with advanced fibrosis or cirrhosis require continuous tenofovir therapy throughout pregnancy regardless of viral load 1, 2. These patients should never discontinue treatment due to risk of hepatic decompensation.
Drug Selection
Tenofovir disoproxil fumarate is the first-line agent for HBV treatment in pregnancy 1, 2. It is pregnancy category B (not teratogenic) and has the strongest safety and efficacy data 1.
If a woman is taking entecavir before pregnancy, switch to tenofovir before conception or immediately upon pregnancy recognition 1, 2. Entecavir is pregnancy category C and should not be continued 3.
Lamivudine and telbivudine are also pregnancy category B options 1, but avoid lamivudine for long-term therapy due to high resistance rates 1.
Treatment Duration
- Start at 24-28 weeks gestation 1
- Continue through 12 weeks postpartum 1
- Monitor closely for hepatitis flares after discontinuation in women who stop therapy postpartum 1, 2
Neonatal Prophylaxis
All infants born to HBsAg-positive mothers must receive both HBIG and hepatitis B vaccine within 12 hours of birth, followed by completion of the vaccine series at 1 and 6 months 1, 2. This applies regardless of whether the mother received antiviral therapy.
Do NOT administer HBIG to pregnant women themselves - antepartum maternal HBIG is ineffective at reducing transmission regardless of viral load 1, 2.
Delivery and Invasive Procedures
Vaginal delivery is recommended - cesarean section should not be performed solely to reduce HBV transmission risk 2, 4. Standard obstetric indications should guide delivery mode 2.
Avoid amniocentesis in HBeAg-positive women or those with HBV DNA >5.3 log₁₀ IU/mL due to high transmission risk; strongly prefer non-invasive prenatal testing instead 1, 2.
Breastfeeding
Breastfeeding is safe and should be encouraged in all HBsAg-positive mothers, including those on tenofovir therapy 1, 2. The 2023 EASL guidelines state with 100% consensus that breastfeeding should not be discouraged in HBV-infected mothers 1.
Evidence Quality and Nuances
The most recent and highest quality evidence comes from the 2023 EASL guidelines 1, which provide the strongest recommendations with 100% consensus on key management points. A 2016 meta-analysis of 3,622 pregnant women demonstrated that antiviral therapy reduces mother-to-child transmission by 70% (risk ratio 0.3) without increasing congenital malformations, prematurity, or other adverse outcomes 5.
Earlier U.S. guidelines from 2015 1 recommended a slightly higher viral load threshold (>10^6 IU/mL = >1,000 IU/mL) for initiating therapy, while the 2023 EASL guidelines use >200,000 IU/mL 1. The lower threshold from EASL is more conservative and should be followed to maximize prevention of vertical transmission.
Common Pitfalls to Avoid
- Failing to check viral load at 26-28 weeks leads to missed opportunities for prophylaxis in high-risk women 1, 2
- Continuing entecavir during pregnancy when tenofovir is the evidence-based, safer choice 1, 2
- Using lamivudine for long-term therapy increases resistance risk; tenofovir is superior 1
- Discouraging breastfeeding contradicts current evidence showing safety with proper infant immunoprophylaxis 1, 2
- Performing cesarean delivery solely for HBV when vaginal delivery is equally safe 2, 4