Maternal varicella leading to viremia may transmit the virus to the fetus by either transplacental spread or by ascending infection from lesions in the birth canal. The fetal consequences depend on the time of maternal disease. They range from asymptomatic infection to fetal loss especially in case of severe maternal disease. Neonatal varicella can be expected if a mother contracts chickenpox during the last 3 weeks of pregnancy. After maternal varicella between 4-5 days before and 2 days after delivery, generalized neonatal varicella, leading to death in up to 20% of the cases, may occur since these neonates have not acquired protecting antibodies