Inadequacy of plasma acyclovir levels at delivery in patients with genital herpes receiving oral acyclovir suppressive therapy in late pregnancy.

Publication Type:

Journal Article


Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstétrique et gynécologie du Canada : JOGC, Volume 31, Issue 12, p.1137-43 (2009)


2009, Acyclovir, Administration, Oral, Adult, Antiviral Agents, Cohort Studies, Delivery, Obstetric, Dose-Response Relationship, Drug, Female, Fetal Blood, Herpes Genitalis, Humans, Infant, Newborn, Infectious Disease Transmission, Vertical, Labor, Obstetric, PREGNANCY, Pregnancy Complications, Infectious, RECURRENCE, Simplexvirus, Treatment Outcome, Vaccine and Infectious Disease Institute, Virus Shedding


Acyclovir therapy in late pregnancy among women with recurrent genital herpes is effective in decreasing genital lesion frequency and subclinical viral shedding rates at delivery, thereby decreasing the need for Caesarean section. Despite good adherence and increased dosing schedules, breakthrough lesions and viral shedding are still observed in some women at or near delivery. Anecdotal evidence suggests that low levels of herpes simplex virus replication at delivery may result in transmission to the neonate. Therefore, defining optimal acyclovir dosing during labour and delivery is warranted. Our objectives were to determine actual maternal and fetal acyclovir levels at delivery, and explore associations between acyclovir levels, duration of labour, and time since last acyclovir dose.