What are the risks associated with chickenpox and pregnancy?

Answers from Roger W. Harms, M.D.

If you're pregnant and develop chickenpox (varicella) — a highly contagious viral illness that causes an itchy rash — you and your baby face serious health risks.

If you develop chickenpox during pregnancy, you're at high risk of potentially serious complications — such as pneumonia.

For your baby, the risks depend on the timing. If chickenpox develops during the first 20 weeks of pregnancy — particularly between weeks 8 and 20 — the baby faces a slight risk of a rare group of serious birth defects known as congenital varicella syndrome. A baby who has congenital varicella syndrome might develop:

  • Scars on the skin
  • Low birth weight
  • Problems affecting the arms, legs, brain and eyes

If chickenpox develops during the few days before you deliver, the baby might be born with a potentially life-threatening infection.

If you're exposed to chickenpox during pregnancy and you're not immune, contact your health care provider immediately. He or she might recommend an injection of an immune globulin product that contains antibodies to the chickenpox virus. When given within 10 days of exposure, the immune globulin can prevent chickenpox or reduce its severity. Unfortunately, due to the rareness of congenital varicella syndrome, it isn't clear if this treatment helps protect the developing baby.

If you develop chickenpox during pregnancy, your health care provider might prescribe oral antiviral drugs to reduce the severity of the illness, as well as the risk of complications. If you have chickenpox when you deliver, your baby might be treated with an immune globulin product shortly after birth to prevent or reduce the severity of the illness. If your baby is born with chickenpox, antiviral drugs might be given as well.

If you're considering pregnancy and you haven't already had chickenpox or been immunized, ask your health care provider about the chickenpox vaccine. It's safe for adults, although the Centers for Disease Control and Prevention recommends waiting at least four weeks after vaccination before trying to conceive. If you're not sure whether you're immune, your health care provider can do a simple blood test to find out.

Nov. 21, 2012