Acyclovir suppression to prevent recurrent genital herpes at delivery.

OBJECTIVE: To determine if suppressive acyclovir near term decreased the frequency of clinical recurrences at delivery in women with recurrent genital herpes simplex virus (HSV) infection. METHODS: We conducted a prospective, double-blind, randomized trial in 234 women with recurrent genital herpes. Women with genital infection of any frequency were enrolled. Patients received either suppressive oral acyclovir 400 mg three times daily or an identical placebo after 36 weeks' gestation. Clinical lesions were identified, and HSV cultures were obtained at delivery. The frequencies of clinical and subclinical HSV recurrences at delivery were evaluated. RESULTS: Six percent of patients treated with acyclovir, and 14% of patients treated with placebo had clinical HSV at delivery (p = 0.046). No patients in the acyclovir group had positive HSV cultures, compared with 6% of placebo-treated patients (p = 0.029). There was no significant difference in subclinical HSV shedding in the acyclovir group (0%) compared with the placebo-treated group (3%) (p = 0.102). CONCLUSIONS: Suppressive acyclovir therapy significantly decreased the incidence of clinical genital herpes and the overall incidence of HSV excretion at delivery in patients with previous herpes infection.