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ACOG Update: HSV in Pregnancy Including the Role of Cesarean Delivery


ACOG has reaffirmed its guidelines for management of genital herpes in pregnancy. HSV transmission is via direct contact with an incubation period of 2 to 12 days. There are two types of HSV: HSV-1 and HSV-2. Most cases genital herpes are caused by HSV-2. However, according to the CDC, an increasing proportion of anogenital herpetic infections has been attributed to HSV-1 infection, which is especially prominent among young women. Cesarean section is recommended in the presence of active lesions or when there is risk for shedding. Compare to vaginal delivery, in the presence of virus in genital secretions, transmission may be reduced from 7.7% to 1.2%

Diagnostic Considerations

  • Typical lesions
    • Painful multiple vesicular or ulcerative lesions | Prodromal symptoms may include pain and burning
  • Diagnosis may be difficult as typical lesions may be absent in many infected persons
  • Infection can be confirmed with type-specific laboratory testing
  • Test patients with genital HSV for HIV infection

Virologic Tests

  • Test with cell culture and PCR if patient presents with genital ulcers or other mucocutaneous lesions
  • The sensitivity of viral culture declines for recurrent lesions or with healing
  • PCR assays for HSV DNA, are more sensitive and are increasingly available and test of choice for CNS and systemic infections (e.g., meningitis, encephalitis, and neonatal herpes)

Note: Absence to detect HSV using culture or PCR does not mean infection is not present as shedding may be intermittent

Serologic Tests

Type-Specific Serologic Tests

  • Antibody tests
    • Antibodies develop during first several weeks after infection and persist indefinitely
    • Assays are based on specific glycoproteins that define HSV type: Glycoprotein G2 (HSV-2) and glycoprotein G1 (HSV-1)
    • Request type-specific glycoprotein G (gG)-based serologic assays when performing serology
    • Do not order IgM
      • Not type-specific | May be positive during recurrence

When is Serologic Testing Helpful?

  • Type-specific HSV serologic assays might be useful for the following (CDC)
    • Recurrent genital symptoms or atypical symptoms with negative HSV PCR or culture
    • Clinical diagnosis of genital herpes without laboratory confirmation
    • Patient whose partner has genital herpes

Interpretation of Serologic Tests

  • HSV-2 antibody
    • Almost all HSV-2 infections are sexually acquired and should lead to appropriate counseling
    • HSV-2 antibody implies anogenital infection
  • HSV-1 antibody alone
    • More difficult to interpret
    • May be result of oral infection | However acquisition of genital HSV-1 is increasing and genital HSV-1 also can be asymptomatic

Primary vs Recurrent

First Clinical Episode of Genital Herpes

  • Newly acquired genital herpes can be associated with
    • Prolonged clinical illness (can occur even if initial presentation is relatively mild)
    • Severe genital ulcerations
    • Neurologic involvement
  • First primary episode confirmed if
    • HSV-1 or HSV-2 found in lesions, but are antibody negative
  • All patients with first HSV episode should receive antiviral therapy

Established HSV-2 Infection

  • Symptomatic first genital HSV-2 episode can be expected to have recurrences
  • Associated with intermittent asymptomatic shedding “even in those with longstanding or clinically silent infection” (CDC)
  • Recurrent infection confirmed
    • Type specific virus is detected in lesions with evidence of antibody to the virus type
  • Antiviral therapy can be used
    • As suppressive therapy to reduce the frequency of recurrences or
    • Episodically to ease or shorten lesion duration
    • Suppressive therapy also decreases transmission risk to partner
  • Note: 15% of first outbreaks are actually established infection and not primary


Considerations Specific to Pregnancy

  • History
    • Ask pregnant women about HSV history
  • Onset of labor
    • Patients should be asked about symptoms and examined for lesions
  • In most cases of neonatal herpes, the mother will not have a history of clinically symptomatic infection
    • Transmission usually occurs via shedding in the genital tract although in-utero transmission has been documented
    • First trimester primary outbreak in the first trimester can be teratogenic and associated with neonatal chorioretinitis, microcephaly, and skin lesions
  • Risk of transmission (CDC)
    • Acquired close to term: 30 to 50% | CDC recommends that patients who acquire genital HSV late in pregnancy “should be managed in consultation with maternal-fetal medicine and infectious-disease specialists”
    • Recurrent infection or acquired during first half of pregnancy: <1%
  • Routine HSV-2 serologic screening of pregnant women is not recommended
  • Breastfeeding
    • Acyclovir and valacyclovir appear to be safe during breastfeeding
    • If no lesions on the breast, there is no contraindication to breast feeding
    • Advise careful handwashing with soap and water
    • ACOG points out the risks associated with postnatal neonatal HSV infection and states

…neonatal infection may be acquired from family members other than the woman and from sites other than the genital tract

Most strains of HSV responsible for nosocomial neonatal disease are HSV-1 rather than HSV-2

Women with active lesions should use caution when handling their babies

Treatment Regimens in Pregnancy (CDC)

  • Primary or first episode
    • Acyclovir 400 mg orally three times a day for 7 to 10 days  or  valacyclovir 1 gm orally twice a day for 7 to 10 days (extend treatment if healing not complete after 10 days of therapy)
  • Symptomatic recurrent episode
    • Acyclovir 400 mg orally three times a day for 5 days  or  acyclovir 800 mg orally twice a day for 5 days  or  valacyclovir 500 mg orally twice a day for 3 days  or  valacyclovir 1 gm orally once a day for 5 days
  • Severe HSV disease or complications requiring hospitalization (e.g., disseminated infection, pneumonitis, or hepatitis) or CNS complications (e.g., meningoencephalitis)
    • Acyclovir 5 to 10 mg/kg IV every 8 hours for 2 to 7 days or until clinical improvement is observed, followed by oral antiviral therapy to complete at least 10 days of total therapy
    • HSV encephalitis requires 21 days of IV therapy
    • Impaired renal function warrants an adjustment in acyclovir dosage
  • Suppressive therapy for recurrence
    • Acyclovir 400 mg orally three times a day or valacyclovir 500 mg orally twice a day


  • Treat recurrence in pregnant women
    • Reduce duration and viral shedding
  • History of HSV
    • Offer suppressive viral therapy ≥36 weeks
  • Primary outbreak in third trimester
    • Consider continuing medication until after delivery | Shown to reduce (1) risk of clinical recurrence at delivery (2) cesarean delivery for recurrence and shedding

Mode of Delivery

Assess for the following at time of labor

  • Active lesions or prodromal symptoms
    • Cesarean delivery is recommended
  • HSV history but no active genital lesions or prodromal symptoms
    • Cesarean delivery not recommended
  • Primary or nonprimary first-episode genital HSV infection during the third trimester
    • ACOG states that “Cesarean delivery may be offered due to the possibility of prolonged viral shedding”
  • Nongenital lesions on back, thigh, buttock (after thorough exam to rule out genital lesions)
    • Cover lesions with occlusive dressing
    • May delivery vaginally
  • PROM
    • Term PROM
      • Cesarean delivery is recommended in the presence of active HSV lesions or prodromal symptoms (e.g., vulvar pain or burning)
    • PPROM
      • Risks of prematurity should be weighed against risks of neonatal vertical transmission
      • There is no established preterm gestational age at which immediate delivery recommended in the setting of PPROM
  • Invasive procedures
    • Forceps/Vaccum or internal fetal monitoring: Can be performed if no active lesions
    • Amniocentesis or CVS: Not know to be a risk, but advised to wait for lesions to heal if present

Learn More – Primary Sources:

ACOG Practice Bulletin 220: Management of Genital Herpes in Pregnancy