Varicella (chickenpox) is a common childhood illness. Most adults are immune to the virus because of previous exposure. Pregnant women who contract varicella risk complications such as pneumonia. Varicella may be transmitted from mother to fetus and could cause congenital varicella syndrome or perinatal infection. Susceptibility to varicella should be determined before pregnancy. Varicella zoster immune globulin may be considered for the mother or newborn if exposure occurs. Acyclovir may decrease the risk of maternal complications from infection.