A Randomized Clinical Trial.

Sheffield JS, Hill JB, et al.
Obstetrics and Gynecology, July 2006, 108(1):141-7.
Department of Obstetrics & Gynecology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9032,USA.
Jeanne.Sheffield@utsouthwestern.edu

OBJECTIVE: To measure the efficacy of valacyclovir suppression in late pregnancy to reduce the incidence of recurrent genital herpes in labor and subsequent cesarean delivery.

METHODS: A total of 350 pregnant women with a history of genital herpes were assigned randomly to oral valacyclovir 500 mg twice a day or an identical placebo from 36 weeks of gestation until delivery. In labor, vulvovaginal herpes simplex virus (HSV) culture and polymerase chain reaction (PCR) specimens were collected. Vaginal delivery was permitted if no clinical recurrence or prodromal symptoms were present. Neonatal HSV cultures and laboratory tests were obtained, and infants were followed up for 1 month after delivery. Data were analyzed using chi2 and Student t tests.

RESULTS: One hundred seventy women treated with valacyclovir and 168 women treated with placebo were evaluated. Eighty-two percent of the women had recurrent genital herpes; 12% had first episode, nonprimary genital herpes; and 6% had first episode, primary genital herpes. At delivery, 28 women (8%) had recurrent genital herpes requiring cesarean delivery: 4% in the valacyclovir group and 13% in the placebo group (P = .009). Herpes simplex virus was detected by culture in 2% of the valacyclovir group and 9% [corrected] of the placebo group (P =.02). No infants were diagnosed with neonatal HSV, and there were no significant differences in neonatal complications. There were no significant differences in maternal or obstetric complications in either group.

CONCLUSION: Valacyclovir suppression after 36 weeks of gestation significantly reduces HSV shedding and recurrent genital herpes requiring cesarean delivery.

Dr. H. Comments: This study follows on with previous evidence that acyclovir could reduce the need for caesarian section in women with herpes. So, now two similar drugs are available to reduce the need for caesarian section in women with herpes who are pregnant. Note that there were no cases of neonatal herpes infections in either the placebo or the study drug group. Remember that women with their first herpes outbreaks during the last trimester of pregnancy must be monitored very carefully to decrease the risk of transmitting the virus to the fetus.