Genital Herpes: Treatment Guidelines

, Withington Hospital and University of Manchester


Medscape General Medicine. 1997;1(2) 

In This Article

Pregnancy in An HSV-Infected Woman

When the diagnosis of first-episode genital herpes is made in a pregnant woman, her obstetrician should be informed as soon as possible, particularly if delivery is imminent.

Infection risk to fetus. Women suffering from first-episode genital herpes during pregnancy may be at high risk of spontaneous abortion or low-birth-weight babies resulting from the associated viremia. Rarely does HSV in maternal serum cross the placenta to cause congenital infection. Rather, the greatest risk to a neonate is HSV acquisition by direct contact during passage through an infected birth canal. Occasionally, ascending infection from the mother's genital tract to the neonate may occur immediately before birth, while in other cases the infant may acquire infection postnatally, usually through kissing the baby.[16] These 2 alternative routes of infection help explain why some infants acquire HSV even when delivered by cesarean section with intact placental membranes.

A woman who has first-episode genital herpes near term and delivers vaginally presents the most risk to the neonate. During the first episode, women are more likely to have genital and cervical viral shedding, but not to have developed circulating antibodies. Other factors implicated in transmission include the use of fetal scalp electrodes (trauma facilitates transmission) and ruptured membranes for more than 4 hours in the presence of viral replication.

Several studies have shown that, among neonates infected with HSV, the majority of mothers had no history of symptomatic genital herpes at delivery.[17,18] The herpes infection risk to an infant passing through an infected birth canal has been estimated at between 3% and 5%.[19] Delivery by cesarean section is recommended in the UK if a woman has first-episode genital herpes within 12 weeks of the expected date of delivery. In an emergency, delivery should occur before the membranes have ruptured or preferably within 4 hours of rupture. Vaginal delivery by women who have experienced the first episode more than 12 weeks before their due date does not appear to pose a greater HSV-transmission risk to the fetus. Because a woman with a history of HSV may have an asymptomatic herpes infection at delivery, many obstetricians prefer to deliver via cesarean section.

Pregnant women who have a history of genital herpes prior to conceiving, or who suffer a first episode of genital herpes during the first or second trimester, should be examined during labor. If a suspicious lesion is seen and genital herpes suspected, then a cesarean section should be considered. Whenever possible, samples for viral identification should be taken from any visible lesion. If no suspicious lesions are seen, then normal vaginal delivery should be allowed.[20]

If a neonate born to a woman with a history of herpes shows signs of infection, such as poor feeding or cerebral irritability, specimens should be taken from the baby for viral identification and systemic acyclovir considered until the results of the viral specimens are known. Other causes of the neonate's condition should also be explored.

Prelabor management. Women who experience a first episode of genital herpes during the first 28 weeks of pregnancy should be treated with an antiviral. Although experience is limited, the incidence of birth defects in women on antivirals does not seem to be substantially higher than in the general population.

If a pregnant woman is at risk for infection by a sexual partner who has recurrent genital herpes, she should advise her partner to use condoms during sexual intercourse, particularly during the third trimester. The woman should be examined carefully during early labor for any suspicious lesions on the external genitalia and cervix.

In couples at high risk for herpes--for example, because of frequent past STDs or multiple sexual partners--serologic testing in the absence of any signs of herpes may be advisable. Testing the male partner of a pregnant woman can be useful in determining her risk for herpes infection and in managing the infection and the pregnancy. Serologic tests are available for detecting HSV-2 antibodies in the male partners of at-risk seronegative mothers; if positive, these couples should be advised to abstain from sexual intercourse or to use condoms during the third trimester. Although screening a male partner for HSV-2 would not exclude the possibility of a neonate being infected with HSV-1, neonates who develop HSV-1 encephalitis fare much better neurologically than those with HSV-2 encephalitis.[21]