Herpes Simplex, Primary or Recurrent

Potential Effect on Fetus

   In Utero:

Primary

• Congenital Syndrome (rare)

   Neonatal:

Primary and Recurrent

• Mucocutaneous lesions
• Disseminated disease
• Encephalitis

Rate of Perinatal Transmission

• Transmission occurs at time of delivery in up to 90% of cases.
• Vaginal delivery:
  • primary – 30-50%
  • recurrent – 2-5%
• Neonatal HSV infection affects 1/17,000 births (half of these related to primary infection).
  • 59% of neonatal disease is skin/eye/ mouth
  • 23% encephalitis
  • 18% disseminated disease

Maternal Screening

- Consult Virology lab in event of suspected primary infection in pregnancy. 

- Inspect for lesions at time of delivery (maternal shedding can occur in the absence of lesions).

Prevention

   Primary infection:

- Consult Infectious Diseases for treatment.

- If occurs in 3^rd trimester, consider pre-labour booked ceasarean section.

   Recurrent infection:

- In women with known recurrent disease, recommend prophylaxis at 36 weeks to delivery with acyclovir 400mg PO tid.

- If lesions present at time of delivery, recommend ceasarean section.