Genital herpes simplex virus infection and pregnancy

●During pregnancy, the major complication of maternal herpes simplex virus (HSV) infection is transmission to the newborn, as neonatal infection can result in serious morbidity and mortality.

●The classification of genital HSV infection includes: primary, nonprimary first-episode genital, and recurrent infection. Clinical findings of HSV infection are similar in pregnant and nonpregnant women. 

●The clinical diagnosis of genital herpes simplex virus infection is generally made by the finding of vesicular or ulcerated genital lesions and should be confirmed with laboratory testing. The approach to diagnosis of genital HSV during pregnancy depends on the clinical presentation. For women without a history of genital HSV who present with an active genital ulcer during pregnancy, we perform a direct viral test on the lesion and type-specific serologic testing. Genital HSV infection is diagnosed by a positive viral test from the lesion, and concurrent serologic testing is used to classify maternal infection

●Transmission of HSV to neonates usually occurs during labor and delivery as a result of direct contact with virus shed from infected sites (vulva, vagina, cervix, perianal area). Viral shedding can occur when maternal symptoms and lesions are absent. 

●The highest risk for neonatal infection occurs in women with a newly acquired (primary or nonprimary first-episode) genital HSV infection near the time of delivery. The risk of neonatal infection is substantially lower in women with recurrent HSV infection. Other predictors of neonatal infection in women with viral shedding during labor include invasive fetal monitoring and premature delivery. 

●For women without a history of genital HSV who present with a new genital ulcer during pregnancy, we recommend empiric antiviral therapy while awaiting viral studies (Grade 1A). We use acyclovir 400 mg orally three times daily for 7 to 10 days (treatment can be extended if healing is incomplete after 10 days); valacyclovir is an alternative. Antiviral therapy can lessen the duration of lesions and viral shedding and decrease the risk of complications in the pregnant women. Most recurrent episodes are short-lived and do not require intervention for symptoms. 

●For all women who present with a genital HSV lesion anytime during pregnancy, whether with a primary, nonprimary first-episode, or recurrent infection, we recommend daily suppressive therapy at 36 weeks of gestation until the onset of labor rather than no therapy (Grade 1A). We use acyclovir 400 mg orally three times daily; valacyclovir is an alternative. Suppressive therapy reduces the risk of clinical recurrence of HSV delivery, and thus the need for cesarean delivery. However, the clinical impact on neonatal HSV is unknown. 

●Use of acyclovir during pregnancy appears to be safe for the fetus at all stages of pregnancy. Data are more limited but reassuring regarding the use of valacyclovir.

●Cesarean delivery can decrease but not eliminate the risk of neonatal HSV infection. For women with a history of HSV and genital HSV lesions or prodromal HSV symptoms at the time of labor, we recommend cesarean delivery (Grade 1B). For women who had a primary or nonprimary first-episode genital infection during the latter weeks of pregnancy (eg, within six weeks of delivery) but have no active lesions at the time of labor, we suggest cesarean delivery (Grade 2C). However, optimal management in such cases is unclear, and after discussion of the uncertain risks of transmission, some women may reasonably choose to forgo cesarean.

●Clinical decision-making for patients with preterm prelabor rupture of membranes (PPROM) and active HSV infection requires weighing the risks associated with preterm birth versus the risk of fetal/neonatal HSV infection. The risks associated with preterm birth depend on the week of gestation; the risk of fetal/neonatal HSV infection is difficult to estimate and depends, in part, on whether the woman’s clinical episode represents primary or recurrent infection. 

•In women with PPROM and recurrent HSV infection, we suggest expectant management remote from term (Grade 2C). We prescribe a course of antenatal corticosteroids to pregnancies <34 weeks to reduce the morbidity and mortality related to preterm birth and intravenous acyclovir (5 mg/kg every 8 hours) to shorten the duration of active lesions and to decrease viral burden.

•There are no clinical trials evaluating the optimum management of women with PPROM and primary or first-episode genital nonprimary HSV infection. Before 28 to 32 weeks, the risks of prematurity are high and may outweigh the risk of fetal/neonatal infection with expectant management.

–Remote from term, we give acyclovir to the mother to shorten the duration of lesions and reduce viral shedding; there are no data showing prevention of neonatal infection. We also give a course of antenatal corticosteroids to reduce the morbidity and mortality related to preterm birth.

–Closer to term, immediate cesarean delivery is preferable because of the overall high risk of fetal/neonatal transmission associated with first-episode genital HSV infection. The neonate is then treated with acyclovir and surfactant.