Acyclovir suppression to prevent cesarean delivery after first-episode genital herpes.

Objective: To determine if suppressive acyclovir therapy given to term gravidas experiencing a first episode of genital herpes simplex virus (HSV)-infection during pregnancy decreases the need for cesarean delivery for that indication.
Methods: Forty-six pregnant women with first episodes of genital herpes during pregnancy were randomly assigned to receive oral acyclovir 400 mg or placebo, three times per day, from 36 weeks' gestation until delivery as part of a prospective, double-blind trial. Herpes simplex virus cultures were obtained when patients presented for delivery. Vaginal delivery was permitted if no clinical recurrence was present; otherwise, a cesarean was performed. Neonatal HSV cultures were obtained and infants were followed-up clinically.
Results: None of the 21 patients treated with acyclovir and nine of 25 (36%) treated with placebo had clinical evidence of recurrent genital herpes at delivery (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.002-0.745; P = .002). No woman treated with acyclovir had a cesarean for herpes, compared with nine of 25 (36%) of those treated with placebo (OR 0.04, CI 0.002-0.745; P = .002). No patient in either treatment group experienced asymptomatic genital viral shedding at delivery. No neonate had evidence of herpes infection or adverse effects from acyclovir.
Conclusion: Suppressive acyclovir therapy reduced the need for cesarean for recurrent herpes in women whose first clinical episode of genital HSV occurred during pregnancy. Suppressive acyclovir treatment did not increase asymptomatic viral shedding and was not harmful to the term fetus.