What is the recommended management approach for a 5-month pregnant patient with a herpes simplex infection and a history of recurrent episodes?

Management of Herpes Simplex Infection at 5 Months Pregnancy

For a pregnant patient at 5 months gestation with herpes simplex infection, treat acute episodes with oral acyclovir 400 mg three times daily for 7-10 days, and plan for suppressive therapy starting at 36 weeks gestation with acyclovir 400 mg three times daily until delivery to prevent recurrence at term. 1

Acute Episode Management (Currently at 20 Weeks)

First Episode Treatment

• Oral acyclovir 400 mg three times daily for 7-10 days is the CDC-recommended first-line treatment for acute genital herpes during pregnancy. 1
• Valacyclovir 1 g orally twice daily for 7-10 days is an equally acceptable alternative for first episode treatment. 1
• Treatment is most effective when initiated within 48 hours of symptom onset. 1

Recurrent Episode Treatment

• For recurrent episodes during pregnancy (not the first episode), the same acyclovir 400 mg three times daily regimen can be used for 5 days. 2
• Alternative regimens include acyclovir 800 mg twice daily for 5 days or acyclovir 200 mg five times daily for 5 days. 2
• Episodic therapy works best when started during prodrome or within 1 day of lesion onset. 2

Safety Reassurance

• Current CDC registry data show no increased risk for major birth defects after acyclovir treatment compared with the general population. 1
• Acyclovir pharmacokinetics in late pregnancy are similar to non-pregnant adults, with no fetal accumulation (mean maternal/infant plasma ratio 1.3). 3
• The ACOG confirms that oral acyclovir may be used to treat first clinical episodes during pregnancy. 1

Suppressive Therapy Planning (Starting at 36 Weeks)

Indication and Timing

• All pregnant women with a history of genital herpes—whether first episode or recurrent—should receive suppressive acyclovir starting at 36 weeks gestation until delivery. 1
• This approach is critical because the risk of neonatal transmission is 30-50% if herpes is acquired near delivery, versus ≤3% with recurrent herpes at term. 1

Suppressive Regimen

• Acyclovir 400 mg orally three times daily from 36 weeks until delivery is the standard suppressive regimen. 1, 4
• In the landmark randomized trial by Scott et al., suppressive acyclovir eliminated clinical recurrences at delivery (0% vs 36% with placebo, P=0.002) and eliminated cesarean deliveries for herpes indication. 5
• A subsequent open-label study showed only 1% clinical recurrence rate in compliant patients versus 18-37% in historical controls. 4

Alternative Suppressive Options

• Valacyclovir 500 mg twice daily from 36 weeks is an alternative, though acyclovir has more extensive pregnancy safety data. 6
• One trial showed valacyclovir reduced clinical recurrences (10.5% vs 27.3% placebo, P=0.023) but had less dramatic effect than acyclovir studies. 6

Delivery Management

Clinical Assessment at Labor

• Cesarean delivery is mandatory for women with active genital lesions or prodromal symptoms at the time of delivery. 1
• Women without symptoms or signs of genital herpes at labor onset may deliver vaginally. 1
• Viral cultures during pregnancy do not predict shedding at delivery and are not routinely indicated. 1

Neonatal Considerations

• Infants delivered through an infected birth canal should be followed with viral cultures obtained 24-48 hours after birth. 1
• Treatment should be reserved for infants who develop clinical disease or have positive cultures—do not routinely treat asymptomatic infants. 1
• Most mothers of infants who acquire neonatal herpes lack histories of clinically evident genital herpes, emphasizing the importance of suppressive therapy. 1

Patient Counseling Points

Disease Education

• Explain that genital herpes is recurrent and incurable, but antiviral therapy controls symptoms and reduces transmission risk. 2
• Inform the patient about the 30-50% neonatal transmission risk if herpes is acquired near delivery versus the ≤3% risk with recurrent disease at term. 1
• Counsel that asymptomatic viral shedding can occur even without visible lesions. 2

Behavioral Recommendations

• Advise abstaining from sexual activity when lesions or prodromal symptoms are present. 7
• Strongly counsel to avoid unprotected genital and oral sexual contact during late pregnancy, especially with partners who have oral or genital HSV infection. 1
• Recommend condom use during all sexual exposures with new or uninfected partners. 2

Healthcare Communication

• Instruct the patient to inform all healthcare providers caring for her during pregnancy about the HSV infection. 1
• Ensure she understands the plan for suppressive therapy starting at 36 weeks. 1

Critical Pitfalls to Avoid

• Do not use topical acyclovir—it is substantially less effective than oral therapy. 2, 8
• Do not withhold treatment during pregnancy based on outdated concerns; current evidence strongly supports safety and efficacy. 1, 5
• Do not obtain routine viral cultures during pregnancy to predict delivery shedding—they are not predictive. 1
• Be aware that some women may have inadequate acyclovir levels at delivery despite compliance, particularly with prolonged labor or delayed dosing. 9
• Do not use valacyclovir 8 grams per day in any patient—it is associated with hemolytic uremic syndrome/thrombotic thrombocytopenic purpura in immunocompromised patients. 2

Severe Disease Exception

• For life-threatening maternal HSV infection (disseminated infection, encephalitis, pneumonitis, or hepatitis), use intravenous acyclovir 5-10 mg/kg every 8 hours for 5-7 days—the benefits clearly outweigh any theoretical risks. 7, 1