Hepatitis B Postexposure Prophylaxis in Newborns

1. See Also
   1. Postexposure Prophylaxis for Hepatitis B
   2. Hepatitis B
2. Epidemiology
   1. U.S. Mothers with Chronic Hepatitis B: 19,000 per year
   2. U.S. Prevalence: 4.9%
3. Pathophysiology
   1. Vertical transmission is uncommon prior to delivery (represents only 5% of cases)
      1. Risk of in utero transmission increases if high viral load and HebBeAg positive
   2. Vertical transmission risk to newborn from HBsAg positive mother
      1. HBeAg Negative: 10% vertical transmission risk
      2. HBeAg Positive: 70-90% vertical transmission risk
   3. Outcomes from perinatal Hepatitis B infection
      1. One quarter with die in adulthood from Cirrhosis or liver cancer
4. Efficacy
   1. Prophylaxis prevents 90% of perinatal Hepatitis B infections if given within 12 hours of birth
5. Protocol: Administer HBIG and HepB <12 hours from birth
   1. Screening for Hepatitis B
      1. Indications
         1. All women in pregnancy (as part of Prenatal Labs)
         2. Women presenting to labor and delivery with unknown Hepatitis B status
      2. Management for positive cases
         1. Refer to gastroenterology or infectious disease specialist
         2. Consider for antiviral agents (category B agents include Telbivudine and Tenofovir) under specialist direction
         3. Hospitalize patients with signs or symptoms of hepatic failure
   2. Indications for prophylaxis
      1. Maternal Hepatitis B positive
      2. Maternal Hepatitis B status unknown or positive
   3. Hepatitis B Immunoglobulin (HBIG)
      1. HBIG 0.5 ml within 12 hours of birth
   4. Hepatitis B Vaccine (HepB)
      1. Initial dose within 12 hours of birth
         1. Administer at separate site from HBIG
      2. Repeat Heptavax at exactly 1 and 6 months of age
   5. Factors that do not impact transmission
      1. Ceserean section does not reduce transmission
      2. Breast Feeding does not increase transmission rate
6. Monitoring
   1. Check follow-up Hepatitis B labs at age 9-15 months
      1. Hepatitis B Surface Antigen (HBsAg)
      2. Hepatitis B Surface Antibody (HBsAb)
         1. If Antibody titer <10 mIU/ml, revaccinate with a repeat of entire Hepatitis B series
         2. Retest HBsAb after second series
7. Prevention: Adult transmission
   1. See Hepatitis B
   2. Test all household contacts, sexual contacts, or IVDA contacts
   3. Hepatitis B Vaccine
8. References
   1. Euler (2003) Pediatr Infect Dis J 22:123-9 [PubMed]
   2. Vu Lam (2010) Am Fam Physician 82(10): 1225-9 [PubMed]
   3. (2007) Obstet Gynecol 110(4): 941-56 [PubMed]