Valaciclovir decreases the frequency of vertical transmission among pregnant women with primary cytomegalovirus infection

Référence

Shahar-Nissan K, Pardo J, Peled O, et al. Valaciclovir to prevent vertical transmission of cytomegalovirus after maternal primary infection during pregnancy: a randomised, double-blind, placebo-controlled trial. Lancet 2020;396(10253):779-785.

Sommaire

These researchers in Israel recruited women with serological evidence of a primary CMV infection acquired within 4 weeks before the last reported menstrual period and up to 3 weeks of gestation or during the first trimester of pregnancy. Each woman underwent additional testing to confirm primary infection and its timing. The researchers randomized the women to receive valaciclovir (8 g daily in specially made capsules; n = 50) or placebo (n = 50). They excluded 5 women from each group for nonadherence, termination of the pregnancy, nonviable pregnancy, or if the primary infection was ultimately ruled out. Each woman underwent amniocentesis, at which time a polymerase chain reaction test for CMV was performed. All the valaciclovir-treated women had singleton pregnancies, while 2 placebo-treated women had twins. Although some of the women decided not to have amniocenteses, the researchers tested these neonates' urine for CMV as a proxy. Overall, 5 of 45 (11.1%) of the neonates of valaciclovir-treated women were positive for CMV (via amniocentesis or urine assay) compared with 14 of 47 (29.8%) of the placebo-treated women (number needed to treat = 6; 95% CI 3 - 50). Generally adherence was similar for each group of women and the authors report no difference in the frequency of adverse events. The authors also report that 2 pregnancies among the valaciclovir-treated women did not go to term: one was terminated because of CMV-related brain abnormalities and one was terminated for detection of an unrelated genetic disorder. Among the placebo-treated women, 2 pregnancies were terminated because of CMV-related brain abnormalities and 4 were terminated for other non-CMV related issues.