Herpes simplex infection

Herpes simplex infection in the newborn infant is generally
acquired at the time of birth, but infection early in pregnancy is
probably associated with an increased risk of abortion, late fetal
death, prematurity and structural abnormalities of the central
nervous system. Maternal varicella infection may also affect the
fetus, causing abnormalities of the central nervous system and
cutaneous scars. The risk of a fetus being affected by varicella
infection is not known but is probably less than 10%, with a
critical period during the third and fourth months of
pregnancy. Affected infants seem to have a high perinatal
mortality rate.