What is the management approach for a 22-year-old primigravida (gravida 1, para 0) at 36 weeks gestation with a history of genital herpes simplex virus (HSV) and no current symptoms or lesions?

From the Guidelines

The patient should be started on antiviral suppressive therapy with oral acyclovir 400 mg three times daily or valacyclovir 500 mg twice daily beginning at 36 weeks gestation and continuing until delivery. This recommendation is based on the most recent evidence from the 2022 study published in Clinical Infectious Diseases 1, which suggests that suppressive therapy can reduce the risk of viral shedding, recurrences, and cesarean deliveries in women with a history of genital herpes. The American College of Obstetrics and Gynecology recommends against routine screening for HSV serostatus during pregnancy, but suggests screening pregnant women for a history of genital herpes 1.

Key benefits of suppressive therapy include:

• Decreased risk of viral shedding and recurrences by approximately 75%
• Reduced risk of cesarean deliveries
• Prevention of a primary or recurrent outbreak at the time of delivery, which could necessitate a cesarean section

It is essential to note that the patient should be counseled about watching for symptoms of herpes recurrence and reporting them immediately. If the patient develops active genital lesions or prodromal symptoms at the time of labor, a cesarean delivery should be performed regardless of when the antiviral therapy was initiated. However, if no lesions are present at the onset of labor, vaginal delivery is appropriate even with a history of herpes. The safety of antiviral medications during pregnancy has been established, with acyclovir remaining a category B medication 1.

From the FDA Drug Label

The majority of subjects initiated treatment within 2 hours of onset of symptoms Subjects were randomized to VALTREX 2 grams twice daily on Day 1 followed by placebo on Day 2, VALTREX 2 grams twice daily on Day 1 followed by 1 gram twice daily on Day 2, or placebo on Days 1 and 2. For both treatment groups the median time to lesion healing was 9 days, the median time to cessation of pain was 5 days, and the median time to cessation of viral shedding was 3 days. The median time to lesion healing was 4 days in the group receiving VALTREX 500 mg versus 6 days in the placebo group, and the median time to cessation of viral shedding in subjects with at least 1 positive culture (42% of the overall trial population) was 2 days in the group receiving VALTREX 500 mg versus 4 days in the placebo group Outcomes for the overall trial population are shown in Table 5. Outcomes for the overall trial population are shown in Table 6.

The FDA drug label does not answer the question.

From the Research

Management of Genital Herpes in Pregnancy

• The patient has a history of genital herpes simplex virus (HSV) but has not had an outbreak in several years 2, 3, 4.
• Studies have shown that acyclovir prophylaxis beginning at 36 weeks' gestation can reduce the risk of clinical HSV recurrence at delivery, cesarean delivery for recurrent genital herpes, and the risk of HSV viral shedding at delivery 2, 3, 4.
• Acyclovir suppression therapy has been found to decrease the need for cesarean delivery for recurrent genital herpes in women with a first episode of genital HSV during pregnancy 3.
• The pharmacokinetics of acyclovir in term human pregnancy and neonate have been studied, and the results suggest that acyclovir is well tolerated and does not accumulate in the fetus 5.

Cost-Effectiveness of Acyclovir Prophylaxis

• A cost-effectiveness analysis has shown that acyclovir prophylaxis for pregnant women with a known history of HSV is cost-effective, saving approximately $20 per person and increasing total quality-adjusted life years by 0.01 6.
• The analysis found that acyclovir prophylaxis can prevent neonatal death, affected children, and cesarean deliveries, with a significant reduction in the number of women needing to be treated to prevent these outcomes 6.

Clinical Implications

• The patient's history of genital HSV and current pregnancy status suggest that acyclovir prophylaxis may be beneficial in reducing the risk of clinical recurrence and cesarean delivery 2, 3, 4.
• The patient's lack of symptoms and normal physical examination do not preclude the possibility of asymptomatic viral shedding, which can be reduced with acyclovir prophylaxis 4.