Chickenpox infection in pregnancy

Primary chickenpox infections during pregnancy are not common. Fetal chickenpox syndrome is more rare after 20 weeks of pregnancy. But once it happens, it can have many adverse effects on the mother and her offspring. Varicella virus is one of the few teratogenic viruses. If it is found within 12 weeks of pregnancy, it has a 0.4% chance of causing fetal malformation. When it is found between 13 and 20 weeks of pregnancy, the chance is 2%.