What is the recommended post-delivery management for a mother who is Hepatitis B surface antigen (HBsAg) positive and Hepatitis B core antigen (HBcAg) positive during pregnancy?

Post-Delivery Management for HBsAg-Positive Mothers

All infants born to HBsAg-positive mothers must receive both hepatitis B vaccine and HBIG (0.5 mL) within 12 hours of birth at different injection sites, followed by completion of the vaccine series and post-vaccination serologic testing at 9-12 months of age. 1

Immediate Newborn Management (Within 12 Hours)

Standard Birth Weight Infants (≥2,000 grams)

• Administer single-antigen hepatitis B vaccine at one injection site 1
• Administer HBIG (0.5 mL) at a different anatomical site (e.g., separate limbs) 1, 2
• Both must be given within 12 hours of birth to achieve 85-95% efficacy in preventing chronic HBV infection 1, 2, 3
• This combined passive-active prophylaxis reduces transmission risk to only 5-15% 2, 4

Low Birth Weight Infants (<2,000 grams)

• Administer both hepatitis B vaccine and HBIG (0.5 mL) within 12 hours at different sites 1
• Critical difference: The birth dose does NOT count toward the vaccine series due to reduced immunogenicity in preterm infants 1, 2
• These infants require 4 total vaccine doses: the birth dose plus 3 additional doses starting at 1 month of age 1, 2
• Complete the series with final dose not before 24 weeks (164 days) of age 1

Vaccine Series Completion

• Continue hepatitis B vaccine series at 1-2 months and 6 months of age for standard birth weight infants 1
• The final dose must not be administered before 24 weeks (164 days) of age 1
• Combination vaccines containing HBsAg may be used after 6 weeks of age to complete the series 1

Post-Vaccination Serologic Testing (9-12 Months)

All infants born to HBsAg-positive mothers require mandatory testing at 9-12 months of age (typically at the next well-child visit after completing the vaccine series). 1, 2

Testing Protocol

• Test for both anti-HBs and HBsAg 1
• Do NOT test before 9 months to avoid detecting passively acquired anti-HBs from HBIG and to maximize detection of late HBV infection 1
• Do NOT test for anti-HBc as maternal antibodies may persist up to 24 months 1

Interpretation and Management Based on Results

Protected infants (HBsAg-negative, anti-HBs ≥10 mIU/mL):

• No further management needed 1, 2

Non-responders (HBsAg-negative, anti-HBs <10 mIU/mL):

• Revaccinate with a single dose of hepatitis B vaccine 1
• Retest 1-2 months after the single dose 1
• If anti-HBs remains <10 mIU/mL, administer 2 additional doses to complete a second series, then retest 1-2 months after final dose 1
• Alternative approach: Administer a complete second 3-dose series followed by testing 1-2 months after final dose 1
• Do not administer more than two complete vaccine series - available data show no benefit from additional doses 1

Infected infants (HBsAg-positive):

• Refer immediately for appropriate hepatology follow-up and chronic HBV management 1

Maternal Counseling and Breastfeeding

Breastfeeding is safe and should be encouraged immediately after birth for infants who receive proper immunoprophylaxis. 1, 5

• The European Association for the Study of the Liver confirms breastfeeding does not increase HBV transmission risk when infants receive appropriate immunoprophylaxis 5
• No need to delay breastfeeding until after immunization 5
• This applies even for mothers on tenofovir treatment, as breastfeeding remains safe 5
• Monitor and treat any breast conditions (cracked nipples) that could theoretically increase viral exposure 5

Critical Pitfalls to Avoid

• Never delay HBIG or vaccine beyond 12 hours - efficacy decreases significantly with time, though HBIG may provide some protection up to 72 hours 2, 3
• Never skip post-vaccination testing at 9-12 months - this is the only way to identify the 5-15% of prophylaxis failures 1, 2
• Never count the birth dose in low birth weight infants (<2,000g) as part of the series - they need 4 total doses 1, 2
• Never test before 9 months - you will detect passively acquired antibodies from HBIG rather than true vaccine response 1

Hospital Transfer Considerations

• For infants transferred to different facilities after birth (e.g., NICU), staff at both transferring and receiving facilities must communicate regarding vaccination and HBIG status to ensure timely prophylaxis 1