What is the current standard of care for a pregnant woman with a possible history of genital herpes simplex virus (HSV) infection who is not experiencing an active outbreak?

Management of Pregnant Women with Possible History of Genital HSV Without Active Outbreak

For pregnant women with a possible history of genital herpes but no current outbreak, the standard of care is to offer suppressive antiviral therapy starting at 36 weeks gestation, perform careful clinical examination at labor onset, and allow vaginal delivery if no lesions or prodromal symptoms are present.

Risk Stratification and Clinical Context

The key distinction is between women with recurrent herpes (history of prior infection) versus those who might acquire primary infection during pregnancy. This matters because:

• Recurrent herpes at delivery: ~1-3% neonatal transmission risk 1, 2
• Primary infection near delivery: 25-50% neonatal transmission risk 2, 3

Most mothers of infants who acquire neonatal herpes lack histories of clinically evident genital herpes 1, 2, making the "possible history" scenario particularly important to clarify.

Antepartum Management Algorithm

1. History Clarification (Early Pregnancy)

• Document whether the patient has confirmed prior genital herpes diagnosis
• If history is uncertain, do NOT perform routine serologic screening - this is not recommended 4, 5
• Focus on identifying any recurrences during current pregnancy

2. Suppressive Therapy Decision (36 Weeks)

If confirmed history of recurrent genital herpes during current pregnancy:

• Offer suppressive therapy from 36 weeks until delivery 4, 6, 7, 8
• Regimen: Acyclovir 400 mg orally three times daily OR Valacyclovir 500 mg orally twice daily 9, 4, 8
• This reduces viral shedding, recurrences, and need for cesarean delivery 4

If history of genital herpes but NO recurrence during current pregnancy:

• Suppressive therapy is not routinely recommended 3, 8
• However, some clinicians may still offer it as the evidence shows benefit for those with any history of recurrent disease 4

3. Counseling on Prevention of Late Pregnancy Acquisition

For women whose HSV status is uncertain, counsel to:

• Avoid unprotected genital and oral sexual contact if partner has known HSV 2
• This is critical because primary infection near term carries the highest neonatal risk

Intrapartum Management

At Labor Onset - Clinical Assessment Protocol

All women should be:

1. Carefully questioned about prodromal symptoms (tingling, burning, pain) 1, 2
2. Thoroughly examined for any genital lesions 1, 2

Delivery Route Decision

Vaginal delivery is appropriate when:

• No visible lesions present
• No prodromal symptoms
• This applies even with history of recurrent herpes 1, 2

Cesarean delivery is indicated when:

• Active genital lesions or prodrome present at labor onset 9, 4
• Suspected primary infection in third trimester 7, 3

Important caveat: Viral cultures during pregnancy do NOT predict shedding at delivery and are not routinely indicated 1, 2. Management is based on clinical findings at labor, not antepartum testing.

Safety Considerations

Acyclovir has the most extensive safety data in pregnancy:

• Registry data show no increased risk of major birth defects 2
• Remains pregnancy category B 4
• One case-control study suggested possible association with gastroschisis, but confounding factors limit interpretation 4
• Acyclovir is the preferred agent if treatment is needed 9

Common Pitfalls to Avoid

1. Do not perform routine HSV serologic screening - not cost-effective and not recommended by ACOG 4
2. Do not obtain antepartum viral cultures - they don't predict delivery shedding 1, 2
3. Do not automatically perform cesarean for history alone - only if lesions/prodrome present at delivery 1, 2
4. Do not withhold suppressive therapy discussion - should be offered to women with recurrent disease during pregnancy 4

Divergent Evidence Note

Earlier guidelines (1993-1998) 1, 2, 1 were more conservative about routine suppressive therapy, while more recent evidence 4, 6 supports offering it to reduce cesarean rates. The 2021 CDC guidelines 4 represent the most current standard, supporting suppressive therapy from 36 weeks for women with recurrent disease during pregnancy.

The key principle: Clinical examination at delivery drives management decisions, not historical or antepartum testing.