“…Consequently, it has been suggested as prophylaxis in pregnant women (especially if VZIGs are not available) [169] , particularly if administered within seven days of exposure and within 24 h of the onset of the rash [26,54,252,265,266] . The use of acyclovir during pregnancy has been widely debated in the literature: There is general consensus concerning its use when the mother's life is in danger and as a means of reducing the severity of complications occurring in late pregnancy [19,53,151,156,256,267] , but its therapeutic and CVS prophylactic use before the twentieth week of gestation is more controversial; some authors favour its administration always, and others only after 20 wk [10,16,19,53,54,151,156,169,252,256,[267][268][269][270][271] . As the virus crosses the placenta during both viremic phases of incubation, the second of which seems to play a greater role in fetal transmission, it has been suggested that secondary viremia can be prevented or minimised by acyclovir provided that it is not given too early [21,22,26,265] .…”