What is the recommended treatment for genital herpes in pregnancy?

Treatment of Genital Herpes in Pregnancy

For first-episode genital herpes during pregnancy, treat with oral acyclovir 400 mg three times daily for 7-10 days, and for all pregnant women with a history of genital herpes (whether during current pregnancy or prior), initiate suppressive therapy with acyclovir 400 mg three times daily starting at 36 weeks gestation and continuing until delivery. 1, 2

First Clinical Episode During Pregnancy

Treatment Regimens

• Acyclovir 400 mg orally three times daily for 7-10 days is the CDC-recommended first-line treatment for acute genital herpes infection during pregnancy 1, 3
• Alternative option: Valacyclovir 1 g orally twice daily for 7-10 days 1, 3
• Treatment may be extended beyond 10 days if healing is incomplete 3

Safety Profile

• Current registry findings show no increased risk of major birth defects after acyclovir treatment compared to the general population 4, 1, 2
• The FDA label for famciclovir confirms that available pharmacovigilance data have not identified drug-associated risks of major birth defects, miscarriage, or adverse maternal/fetal outcomes 5
• ACOG confirms that the first clinical episode of genital herpes during pregnancy may be treated with oral acyclovir 1

Suppressive Therapy Starting at 36 Weeks

Primary Recommendation

• All pregnant women with a history of genital herpes during the current pregnancy should receive suppressive antiviral prophylaxis starting at 36 weeks gestation 2
• Acyclovir 400 mg orally three times daily until delivery (preferred) 2
• Alternative: Valacyclovir 1000 mg orally twice daily until delivery 2

Evidence Supporting Suppression

• Suppressive acyclovir reduces clinical recurrences at delivery from 18-37% (historical controls) to 0-4% 6, 7
• In a randomized controlled trial, 0% of acyclovir-treated patients versus 36% of placebo-treated patients had clinical recurrences at delivery (OR 0.04,95% CI 0.002-0.745; P = 0.002) 6
• Suppressive therapy significantly reduces the need for cesarean delivery for recurrent herpes 6, 7

Critical Timing

• Do not delay prophylaxis beyond 36 weeks gestation, as the evidence base specifically supports initiation at this timepoint 2
• The benefit is greatest for women who acquired their first episode during the current pregnancy, given the 30-50% neonatal transmission risk with primary infection near delivery 1, 2, 5

Life-Threatening Maternal HSV Infection

Severe Disease Management

• For disseminated infection, encephalitis, pneumonitis, or hepatitis: acyclovir 5-10 mg/kg IV every 8 hours for 5-7 days or until clinical resolution 4, 1, 3
• Intravenous acyclovir is definitively indicated for life-threatening maternal HSV infections, as benefits clearly outweigh any theoretical risks 1

Recurrent Episodes During Pregnancy

Episodic Treatment Options

• While there are no studies specifically evaluating efficacy of antiviral therapy for recurrent episodes during pregnancy, treatment may be given when warranted by symptom severity 8
• Acyclovir 400 mg orally three times daily for 5 days 3
• Alternative: Valacyclovir 500 mg orally twice daily for 5 days 3, 8
• Episodic therapy is most effective when started during prodrome or within 1 day of lesion onset 3

Management at Delivery

Cesarean Delivery Indications

• Cesarean delivery is mandatory if visible genital lesions or prodromal symptoms are present at labor onset, regardless of whether this represents primary or recurrent disease 2
• Cesarean delivery reduces transmission risk by approximately 85% when lesions are present 2
• Women without symptoms or signs of genital herpes at labor onset may deliver vaginally 1

Neonatal Transmission Risk Context

• Primary HSV infection near delivery carries a 30-50% neonatal transmission risk 1, 2, 5
• Recurrent HSV at delivery carries only a 1-3% neonatal transmission risk 2, 5
• Most mothers of infants who acquire neonatal herpes lack histories of clinically evident genital herpes 4, 1

Neonatal Monitoring

Post-Delivery Management

• All infants delivered through an infected birth canal should be followed carefully with viral cultures obtained 24-48 hours after birth 1
• Do not routinely treat asymptomatic infants with acyclovir; reserve treatment only for those who develop clinical disease or have positive postpartum cultures 1

Important Caveats and Pitfalls

Common Errors to Avoid

• Do not use topical acyclovir, as it is substantially less effective than oral therapy and is not recommended 3
• Viral cultures during pregnancy do not predict shedding at delivery and are not routinely indicated 1
• Despite suppressive therapy, breakthrough lesions can still occur; some studies show inadequate plasma acyclovir levels at delivery, particularly with prolonged labor or extended time since last dose 9
• Asymptomatic viral shedding occurs infrequently (approximately 1%) even with suppressive therapy 7, 10

Special Populations

• For HIV-infected pregnant women with frequent, severe recurrences of genital HSV disease, acyclovir or valacyclovir prophylaxis is indicated with the same safety profile 1
• Immunocompromised patients may require higher doses (acyclovir 400 mg orally three to five times daily) 4, 1

Patient Counseling

• Pregnant women should be counseled to avoid unprotected genital and oral sexual contact during late pregnancy, especially with partners who have oral or genital HSV infection 1
• Patients should inform all healthcare providers caring for them during pregnancy about their HSV infection 1, 3
• Explain that antiviral medications control symptoms but do not eradicate the virus 3