From the Guidelines
Paroxysmal supraventricular tachycardia (PSVT) in a newborn exposed to hepatitis B requires prompt management of both conditions, with the newborn receiving hepatitis B immune globulin (HBIG) 0.5 mL intramuscularly within 12 hours of birth, along with the first dose of hepatitis B vaccine, as the most effective approach to prevent hepatitis B infection, as supported by the Advisory Committee on Immunization Practices 1. For PSVT, initial treatment includes vagal maneuvers such as applying an ice pack to the face for 10 seconds. If unsuccessful, adenosine is the first-line medication, administered at 0.1 mg/kg rapid IV push, which can be increased to 0.2 mg/kg if needed. The hepatitis B vaccine series continues with additional doses at 1-2 months and 6 months of age. PSVT management is not affected by hepatitis B exposure, and both conditions can be treated simultaneously. PSVT occurs due to abnormal electrical conduction pathways in the heart, while hepatitis B prophylaxis works by providing passive immunity (HBIG) and stimulating active immunity (vaccine) to prevent viral infection. Key points to consider in managing hepatitis B exposure in newborns include:
- The birth dose of hepatitis B vaccine serves as postexposure prophylaxis to prevent perinatal HBV infection among infants born to HBV-infected mothers 1.
- Hepatitis B vaccine or HBIG given alone are 75% and 71% effective in preventing perinatal HBV transmission, respectively; their combined efficacy is 94% 1.
- Vaccination produces seroprotection in 98% of healthy term infants, with vaccine response being lower among infants with birth weights <2000 grams 1. Close cardiac monitoring and follow-up with both cardiology and infectious disease specialists are essential for optimal outcomes. The most recent and highest quality study, published in 2018, supports the use of hepatitis B vaccine and HBIG in preventing perinatal HBV transmission 1. In areas where HBV is highly endemic, HBV frequently is transmitted perinatally from HBV-infected pregnant women to their newborns, making prompt management of both PSVT and hepatitis B exposure crucial 1.
From the Research
PSVT on Newborn Exposed to Hep B
- The use of Hepatitis B immune globulin (HBIG) is recommended for perinatal exposure of infants born to HBsAg-positive mothers 2, 3.
- HBIG provides immediate passive protection against infection with hepatitis B virus, after acute exposure to infection 3.
- A hepatitis B vaccination (HepB) series with an initial dose of HBIG is the recommended prophylaxis for infants born to mothers with chronic hepatitis B virus (HBV) infection 4.
- Administration of HBIG with HepB can delay and reduce responses to HepB in mice, but the initial circulating levels of HBIG could prevent infection despite an impaired response to vaccine 4.
- The principal indications for administration of HBIG include mother-to-infant transmission, and it is now generally combined with active immunization with hepatitis B vaccine 3.
- Preexposure vaccination results in protective antibody levels in almost all infants and children (> 95%) and healthy adults younger than 40 years of age (> 90%) 5.