New data on efficacy of valaciclovir in secondary prevention of maternal-fetal transmission of CMV. 


Objective: Congenital cytomegalovirus (CMV) infection is the leading cause of non-genetic hearing and neurological deficits. The aim of our study was to evaluate the efficacy and safety of valaciclovir (VCV) in prevention of CMV transmission to the fetus after maternal primary infection.

Methods: Retrospective, multicenter study evaluating the rate of CMV maternal-fetal transmission in patients with a primary CMV infection treated with VCV at a dosage of 8g per day (VCV group) compared to a group of untreated women. Each case was assessed virologically to confirm maternal primary infection and to provide accurate dating. The primary endpoint was the presence of congenital CMV infection diagnosed on urine samples at birth. The efficacy of VCV treatment was assessed using logistic regression analysis adjusted for a propensity score.

Results: 143 patients were included in the final analysis, 59 in the VCV group, and 84 in the control group. After propensity score adjusted analysis, VCV treatment was significantly associated with an overall reduction in the rate of maternal-fetal transmission (OR = 0.40; 95% CI 0.18-0.90, p=0.03). After periconceptional primary infection, the rate of maternal-fetal transmission at birth was 7% (1/14) in the VCV group vs 10% (1/10) in the control group (p=1.00); 22% (8/36) vs 41% (19/46) after 1st trimester maternal primary infection (p=0.07) and 25% (2/8) vs 52% (14/27) after 2nd trimester maternal primary infection (p=0.24). When analyzing efficacy of treatment according to maternal viremia at treatment initiation, there was a trend towards greater efficacy when viremia was positive (21% vs 43%, p=0.07) compared to when viremia was negative (22% vs 17%, p=0.66). Maternal treatment side effects are reported.

Conclusion: VCV treatment of pregnant women with primary CMV infection in the first and second trimesters reduces the risk of transmission to the fetus. This article is protected by copyright. All rights