Management of Pregnant Woman Non-Immune to Hepatitis B with Titre of 9.6
A titre of 9.6 mIU/mL indicates inadequate immunity to hepatitis B (below the protective threshold of 10 mIU/mL), and this pregnant woman should receive hepatitis B vaccination during pregnancy to establish protective immunity. 1, 2
Understanding the Titre Result
- Antibody titres ≥10 mIU/mL against HBsAg are recognized as conferring protection against hepatitis B, while titres ≥1 mIU/mL indicate seroconversion 3
- Your patient's titre of 9.6 mIU/mL falls just below the protective threshold, leaving her susceptible to hepatitis B infection during pregnancy 3
- This non-immune status poses risks for both acute infection during pregnancy and potential perinatal transmission if infection occurs 2
Recommended Management Algorithm
Immediate Actions
Administer hepatitis B vaccine series during pregnancy. The Society for Maternal-Fetal Medicine recommends hepatitis B vaccination in pregnancy for all individuals without serologic evidence of immunity or documented history of vaccination 2. Both hepatitis B vaccine and immunoglobulin can be used safely in pregnancy 4, 5.
- Hepatitis B vaccine is safe and immunogenic in pregnant women, with no significant adverse effects observed in mothers or newborns 6
- The standard vaccination schedule consists of three doses at 0,1, and 6 months 3
- Studies demonstrate 84% seroconversion rates after two doses in the third trimester, with 100% seroconversion after the complete series 6, 3
Important Caveats About Pregnancy Vaccination
Be aware that immune response to hepatitis B vaccine may be slower and lower in pregnant women compared to non-pregnant individuals. 5
- Pregnant women achieve relatively lower peak geometric mean titers (258 IU/L) compared to non-pregnant women (684 IU/L) 5
- Monitor anti-HBs levels 1 month after the initial vaccination series to confirm adequate response 5
- If the patient delivers before completing the series, continue vaccinations postpartum 2
Screening Considerations
Confirm hepatitis B surface antigen (HBsAg) status if not already documented. 2
- Universal HBsAg screening is recommended at the initial prenatal visit for all pregnancies 2
- Triple-panel testing (HBsAg, anti-HBs, and anti-HBc) provides comprehensive assessment of infection and immunity status 2
- Repeat HBsAg testing at delivery admission if the patient has risk factors for acute infection 2
Neonatal Protection Planning
Ensure the newborn receives standard hepatitis B vaccine within 12 hours of birth. 2
- All newborns should receive hepatitis B vaccine regardless of maternal vaccination status during pregnancy 2
- Hepatitis B immunoglobulin (HBIG) is NOT indicated for infants of mothers who are HBsAg-negative 1, 2
- Passive transfer of maternal antibodies to the infant is short-lived (disappearing by 3 months), making early infant vaccination critical 6
Breastfeeding Guidance
Breastfeeding is safe and should be encouraged. 1, 7
- There is no contraindication to breastfeeding in HBsAg-negative mothers receiving hepatitis B vaccination 7
- The benefits of breastfeeding outweigh any theoretical concerns 7
Common Pitfalls to Avoid
- Do not delay vaccination thinking it should wait until after pregnancy—vaccination during pregnancy is both safe and recommended 2, 6
- Do not assume a titre of 9.6 provides adequate protection—it falls below the 10 mIU/mL protective threshold 3
- Do not forget to verify HBsAg status before assuming the patient is simply non-immune rather than chronically infected 2
- Do not rely on passive antibody transfer to protect the infant—maternal antibodies disappear rapidly and infant vaccination is essential 6