What is the recommended treatment for herpes simplex virus (HSV) in pregnancy?

Treatment of Herpes Simplex Virus in Pregnancy

Oral acyclovir 400 mg three times daily for 7-10 days is the recommended first-line treatment for first-episode genital herpes during pregnancy, with valacyclovir 1 g twice daily for 7-10 days as an acceptable alternative. 1

First Episode Treatment Options

• Acyclovir 400 mg orally three times daily for 7-10 days is the recommended first-line treatment for first episodes of genital herpes during pregnancy 1, 2
• Valacyclovir 1 g orally twice daily for 7-10 days is an effective alternative treatment option 1
• For life-threatening maternal HSV infection (e.g., disseminated infection, encephalitis, pneumonitis, or hepatitis), intravenous acyclovir is indicated 2, 1

Safety in Pregnancy

• Current registry findings do not indicate an increased risk for major birth defects after acyclovir treatment compared with the general population 1, 3
• The Acyclovir Registry documented outcomes of 1,246 infants exposed to acyclovir during pregnancy, with major birth defects occurring in 2.6% across all trimesters, which is comparable to the general population rate of 2-4% 3
• The Valacyclovir Pregnancy Registry showed similar safety data with no significant increase in birth defects 3
• Acyclovir is the antiviral drug with the most reported experience in pregnancy and appears to be safe 2

Management of Recurrent Herpes in Pregnancy

• Suppressive therapy with acyclovir 400 mg three times daily starting at 36 weeks gestation significantly reduces clinical recurrences at delivery 4, 5
• Valacyclovir suppression (500 mg twice daily) after 36 weeks gestation significantly reduces HSV shedding and recurrent genital herpes requiring cesarean delivery 6
• In clinical trials, suppressive acyclovir therapy reduced the need for cesarean delivery for recurrent herpes from 36% in placebo groups to 0-4% in treatment groups 4, 6
• Suppressive therapy does not increase asymptomatic viral shedding and has not shown harmful effects to the term fetus 4, 7

Risk of Neonatal Transmission

• The risk for transmission to the neonate is high (30%-50%) among women who acquire genital herpes near the time of delivery 2, 1
• The risk is low (≤3%) among women with a history of recurrent herpes at term 2, 1
• Most mothers of infants who acquire neonatal herpes lack histories of clinically evident genital herpes 2, 1
• Cesarean delivery is indicated for women with active genital lesions or prodromal symptoms at the time of delivery 1

Special Considerations for Immunocompromised Patients

• Immunocompromised patients, including those with HIV, might have prolonged and/or severe episodes of genital herpes 1
• Higher doses of antiviral drugs are often beneficial for HIV-infected patients 1
• Acyclovir 400 mg orally 3-5 times a day is recommended for immunocompromised patients 1, 2
• If lesions persist during acyclovir treatment, resistance should be suspected 1
• For acyclovir-resistant HSV, intravenous foscarnet (40 mg/kg body weight every 8 hours) is the treatment of choice 2

Counseling Points

• Explain the risk of neonatal infection to all pregnant women with genital herpes 1
• Advise patients to inform healthcare providers who care for them during pregnancy about their HSV infection 1
• Counsel women to avoid unprotected genital and oral sexual contact during late pregnancy, especially with partners who have oral or genital HSV infection 1
• At the onset of labor, all women should be examined and questioned regarding symptoms of genital herpes 2

Algorithm for Management

1. First episode during pregnancy:

   • Treat with oral acyclovir 400 mg three times daily for 7-10 days 1
   • Alternative: valacyclovir 1 g twice daily for 7-10 days 1

2. History of recurrent genital herpes:

   • Initiate suppressive therapy at 36 weeks gestation:
     • Acyclovir 400 mg three times daily until delivery 4, 5, or
     • Valacyclovir 500 mg twice daily until delivery 6

3. At delivery:

   • If no active lesions or prodromal symptoms: vaginal delivery is appropriate 2
   • If active lesions or prodromal symptoms present: cesarean delivery is indicated 1

4. For immunocompromised patients:

   • Consider higher doses: acyclovir 400 mg 3-5 times daily 1
   • Monitor closely for treatment failure and potential resistance 1