Characteristics and management of pregnancy in women with genital herpes simplex virus infection.

The natural history of genital herpes simplex virus (HSV) infections was investigated in 83 pregnancies in 78 women, and the information was used to determine the need for cesarean section in these women. We studied 163 recurrent episodes with HSV cultures from the cervix and from vulvar lesions every 1 to 3 days. Cervical HSV cultures were obtained weekly from asymptomatic women beginning at 32 weeks' gestation, and 14/462 (3.03%) of these cultures were positive. Cervical cultures obtained during culture-positive vulvar recurrences demonstrated concomitant cervical HSV shedding in 25/165 (15.2%) cultures. Mean duration of 26 genital HSV recurrences was 4.6 +/- 2.8 days with a range of 1 to 13 days. The mean interval between culture-positive HSV recurrences was 59.2 +/- 42.1 days, but many (14/76 = 18%) intervals were less than 21 days. Viral cultures were already positive in 92.3% of cases after 4 days' incubation, so they could be used effectively to determine route of delivery. Following a cautious set of criteria for vaginal delivery in these women, 69.1% were delivered of their infants vaginally and no neonatal morbidity caused by HSV was encountered. Information about the natural history of genital HSV infections obtained from frequent third-trimester viral cultures can be used to manage pregnancy and will reduce the need for cesarean section while avoiding neonatal HSV morbidity.