What are the risks and management options for a pregnant woman exposed to shingles?

Management of Shingles Exposure During Pregnancy

Pregnant women exposed to shingles (herpes zoster) generally have minimal risk to the fetus, but management with varicella zoster immune globulin (VZIG) is recommended for susceptible women within 96 hours of exposure.

Risk Assessment

When a pregnant woman is exposed to someone with shingles, the first step is to determine her immunity status:

• Immunity assessment: Document varicella immunity status based on:
  • History of previous chickenpox infection
  • Previous varicella vaccination
  • VZV IgG serology

Management Algorithm

For VZV-Susceptible Pregnant Women (no history of chickenpox/shingles or negative serology)

1. Administer VZIG: Should be given within 96 hours after exposure to shingles 1

   • VZIG provides passive immunity and may prevent or modify the severity of infection

2. If VZIG is unavailable or >96 hours have passed:

   • Consider oral acyclovir prophylaxis 2
   • Monitor closely for development of symptoms

3. Monitoring: Watch for signs of varicella infection for 21 days after exposure

   • Fever
   • Malaise
   • Characteristic vesicular rash

For VZV-Immune Pregnant Women

• No specific intervention needed
• Reassure that prior immunity provides protection
• Risk of developing shingles from exposure is extremely low

If Varicella Infection Develops

If a pregnant woman develops varicella infection following exposure:

1. Oral antiviral treatment: Start acyclovir 800 mg 5 times daily 3

   • Valacyclovir and famciclovir are also options based on FDA pregnancy categories 4, 5
   • Treatment should begin within 24-72 hours of rash onset

2. For severe cases/complications:

   • Consider hospitalization
   • Switch to IV acyclovir 10-15 mg/kg every 8 hours 3

3. Fetal monitoring:

   • Detailed ultrasound to screen for fetal consequences of infection 3
   • Follow-up monitoring as appropriate

Special Considerations

Timing of Infection Risks

• First/second trimester infection: Higher risk of congenital varicella syndrome 3, 6
• Peripartum infection (5 days before to 2 days after delivery): Highest risk for severe neonatal varicella 3

Neonatal Management

• If maternal infection occurs near delivery, inform neonatal healthcare providers 3
• VZIG should be administered to neonates if maternal disease onset is between 5 days before and 2 days after delivery 3

Important Caveats

1. Shingles vs. Chickenpox exposure:

   • Shingles (herpes zoster) is less contagious than chickenpox
   • Transmission from shingles requires direct contact with lesions in most cases
   • The risk of fetal infection from maternal exposure to shingles is lower than from exposure to chickenpox

2. Vaccine contraindication:

   • Varicella vaccine should NOT be administered during pregnancy 1, 3
   • Vaccination should be considered postpartum for non-immune women 3

3. Safety of antivirals:

   • No pattern of adverse pregnancy outcomes has been reported with acyclovir use during pregnancy 1, 4
   • The Acyclovir Pregnancy Registry has not shown increased risk of birth defects 4

Remember that while maternal shingles exposure has minimal effect on the fetus, appropriate management is important to prevent maternal infection and its potential complications 7.