Infection of the lower genital tract by herpes simplex virus type 2 (HSV-2) (see also Chapter 6) is a common STD with potentially serious consequences to pregnant women and their newborn infants. Although up to 25% of pregnant women may have antibodies to HSV-2, a history of the infection is unreliable, and the incidence of neonatal infection is not known. There are estimated to be 1200–1500 cases of neonatal infection annually in the United States. Many infected neonates are born to women with no history, symptoms, or signs of infection.
Women who have had primary herpes infection late in pregnancy are at high risk for shedding virus at delivery; however, it can be difficult to differentiate primary from nonprimary infection. Women with a primary infection or nonprimary first outbreak and women with a clinical history of genital herpes should be offered prophylactic acyclovir, 400 mg orally three times daily, starting at 36 weeks’ gestation, to decrease the likelihood of active lesions at the time of labor and delivery. The use of prophylactic acyclovir been shown to decrease the number of cesarean sections performed for active disease. For treatment, see Chapter 32.
Women with a history of recurrent genital herpes have a lower neonatal attack rate than women infected during the pregnancy, but they should still be monitored with clinical observation and culture of any suspicious lesions. Since asymptomatic viral shedding is not predictable by antepartum cultures, recommendations do not include routine cultures in individuals with a history of herpes without active disease. However, when labor begins, vulvar and cervical inspection should be performed. Cesarean delivery is indicated at the time of labor if there are prodromal symptoms or active genital lesions.
American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 220: management of genital herpes in pregnancy. Obstet Gynecol. 2020;135:e193.