In a pregnant woman with recurrent genital herpes, what is the recommended antiviral management, delivery plan, and is routine testing of the newborn for herpes simplex virus required?

Management of Recurrent HSV in Pregnancy: Antiviral Therapy, Delivery Planning, and Neonatal Testing

For pregnant women with recurrent genital herpes, start suppressive acyclovir 400 mg three times daily (or valacyclovir 500 mg twice daily) at 36 weeks gestation, plan cesarean delivery only if active lesions or prodrome are present at labor onset, and obtain neonatal surveillance cultures at 24-48 hours after birth—routine empiric treatment of asymptomatic newborns is not indicated. 1, 2

Antiviral Management During Pregnancy

Suppressive Therapy Starting at 36 Weeks

• Begin suppressive antiviral therapy at 36 weeks gestation with either acyclovir 400 mg orally three times daily OR valacyclovir 500 mg orally twice daily and continue until delivery 1

• This regimen significantly reduces clinical HSV recurrences at delivery (from 27-36% to 5-11%), decreases viral shedding, and reduces cesarean delivery rates by approximately 60-70% 1, 3, 4

• Randomized trials demonstrate that valacyclovir reduces recurrences requiring cesarean from 13% to 4% (p=0.009), and acyclovir prevents recurrence in 100% of treated women versus 64% with placebo 4, 5

Safety Considerations

• Acyclovir remains pregnancy category B with decades of safety data showing no pattern of adverse pregnancy outcomes or major congenital anomalies 1, 6

• Important caveat: One case-control study showed increased odds of gastroschisis (OR 4.7) when antiherpes medications were used between one month before conception through the third month of pregnancy, though this had significant confounders and possible recall bias 1

• The risk-benefit strongly favors suppressive therapy starting at 36 weeks, as this timing avoids the first trimester concern while maximizing prevention of neonatal transmission 1, 6

When NOT to Use Routine Suppression

• Do not routinely prescribe suppressive therapy before 36 weeks in women without frequent or severe recurrences during the current pregnancy 6

• Suppressive therapy is specifically indicated only for women with documented frequent recurrences (≥6 per year) or those who had recurrences during the current pregnancy 1, 6

Delivery Planning Algorithm

Examine Carefully at Labor Onset

• Perform thorough examination of the external genitalia, vaginal canal, and cervix looking specifically for vesicles, ulcers, or any suspicious lesions 2

• Ask directly about prodromal symptoms including tingling, burning, or itching in the genital area 2

Decision Tree for Mode of Delivery

If visible lesions OR prodromal symptoms are present at labor onset:

• Proceed immediately with cesarean delivery regardless of whether this represents primary or recurrent disease 1, 2
• Cesarean reduces transmission risk by approximately 85% when lesions are present 2
• Do NOT rely on antiviral medication given at labor to prevent transmission—cesarean is the standard of care 2

If NO visible lesions AND no prodromal symptoms:

• Proceed with vaginal delivery even in women with a history of recurrent genital herpes 2, 4
• The transmission risk with recurrent infection at delivery is only 1-3% (versus 30-50% for primary infection) 2

Critical Distinction: Recurrent vs. Primary Infection

• Women with recurrent HSV during pregnancy who were on suppressive therapy and have no lesions at delivery can safely deliver vaginally 2, 4

• Women with a first episode (primary infection) in the last 6 weeks of pregnancy should have cesarean delivery even without visible lesions at labor, as viral shedding may persist 7, 2

Neonatal Testing and Management

Surveillance Culture Protocol

All infants born to mothers with recurrent HSV require surveillance cultures at 24-48 hours after birth from the following sites: 2

• Conjunctiva
• Oral cavity
• Nasopharynx
• Rectum

Critical timing: Cultures obtained immediately at delivery are not useful as they reflect maternal contamination rather than true neonatal infection 2

When to Treat the Newborn

DO NOT routinely treat asymptomatic infants born to mothers with recurrent HSV who delivered vaginally without visible lesions 2

START immediate IV acyclovir 20 mg/kg three times daily if: 2

• The infant develops any skin vesicles or lesions
• Surveillance cultures return positive (even if asymptomatic)
• The mother had primary HSV infection in the last month of pregnancy (some experts recommend empiric treatment even if cultures are pending, given 30-50% transmission risk) 2

Observe without treatment if: 2

• The infant is asymptomatic AND
• Surveillance cultures at 24-48 hours are negative AND
• The mother had recurrent (not primary) HSV

What NOT to Do

• Do not use prenatal viral cultures obtained during pregnancy to guide neonatal management—they do not predict viral shedding at delivery 2

• Do not obtain cultures immediately at birth—wait until 24-48 hours to avoid false positives from maternal contamination 2

Common Pitfalls to Avoid

• Pitfall: Starting suppressive therapy too early (before 36 weeks) in women without active recurrences during pregnancy—this exposes the fetus to unnecessary medication without proven benefit 6

• Pitfall: Performing cesarean delivery on all women with a history of genital herpes regardless of lesion status at labor—this leads to unnecessary surgical morbidity when transmission risk is <2% with recurrent disease and no visible lesions 2, 4

• Pitfall: Treating all exposed newborns empirically with acyclovir—this is not indicated for low-risk infants (maternal recurrent HSV, no lesions at delivery, negative surveillance cultures) 2

• Pitfall: Relying on antiviral medication given at the time of labor when active lesions are present—cesarean delivery remains essential as antivirals cannot adequately prevent transmission once lesions are visible 2

Monitoring and Follow-up

• No laboratory monitoring is needed for pregnant women receiving suppressive therapy unless they have substantial renal impairment 6

• All exposed infants should be followed clinically for at least 2 weeks postpartum, with parents instructed to watch for vesicular lesions, fever, lethargy, or poor feeding 2, 3

• After 1 year of continuous suppressive therapy postpartum, consider discontinuation to reassess natural recurrence rate 6