Valaciclovir to Prevent Vertical Transmission of Cytomegalovirus After Maternal Primary Infection During Pregnancy : A Randomized, Double-blind, Placebo-Controlled Trial / Shahar-Nissan, Keren; Pardo, joseph; Peled, Orit; Krause, Irit; Bilavsky, Efraim; Wiznitzer, Arnon; Hadar, Eran; Amirt, Jacob