Chickenpox and pregnancy: What are the concerns?

Chickenpox, also called varicella, is a viral infection that spreads very easily. It causes an itchy rash with small fluid-filled blisters. Other symptoms often include a fever, lack of energy, muscle soreness and feeling very tired. When chickenpox happens during pregnancy, it can lead to serious health concerns.

If you're pregnant

Pregnant people who get chickenpox are at risk of a variety of health problems. The most common is pneumonia, which can be more severe in a pregnant person. For a fetus, the risks depend on when the infection happens. If chickenpox develops during the first 20 weeks of pregnancy, it poses a small risk of a rare group of serious birth defects called congenital varicella syndrome. That condition also is known as fetal varicella syndrome. The risk is highest between eight and 20 weeks of pregnancy.

Congenital varicella syndrome can cause scarring of the skin. It also can cause permanent health concerns that affect the eyes, brain, arms, legs and gastrointestinal tract. These changes may be seen on an ultrasound before birth.

If a chickenpox infection happens during the days or weeks before delivery, the baby may be born with a condition called neonatal varicella. This condition also may happen if a baby gets chickenpox in the first few weeks of life. Neonatal varicella can be life-threatening.

When you're pregnant, it's important to know if you're immune to chickenpox. Being immune means you're not likely to get the infection. Some people develop immunity when they get chickenpox earlier in life. Others are immune because they received the chickenpox vaccine. If you aren't sure if you're immune, your healthcare professional can do a blood test to check. Healthcare professionals may check immunity during routine blood tests early in pregnancy. That way, they'll know if you need treatment for a chickenpox exposure during pregnancy and if you may benefit from a vaccine after delivery.

If you're not immune to chickenpox, and you learn you've been around someone who has chickenpox, contact your healthcare professional right away. You may need a medicine called immune globulin that has antibodies to the chickenpox virus. When given within 10 days of exposure, this medicine can lower the risk of getting chickenpox. If you do get chickenpox, having this medicine in your body can make the infection milder. It's not clear if this medicine helps protect the fetus.

If you get chickenpox during pregnancy, your healthcare professional likely will give you an antiviral medicine to make recovery go faster. The medicine works best when taken within 24 hours of the rash appearing.

If you have chickenpox when you deliver, your baby might be treated with an immune globulin medicine shortly after birth. This may help prevent neonatal varicella. If your baby gets chickenpox in the first several weeks of life, antiviral medicine is used to treat it.

If you're thinking about getting pregnant

You can take steps to protect yourself from chickenpox before you get pregnant. If you have not had chickenpox or been vaccinated, ask your healthcare professional about getting the chickenpox vaccine before pregnancy. It's safe for adults. But wait at least one month after your second dose of the vaccine before trying to get pregnant.