Lack of varicella (chickenpox) immunity

Varicella, commonly known as chickenpox, is a viral infection that causes an itchy rash. It’s usually not dangerous in children but can cause serious health problems for you and your baby if you catch it during pregnancy. If you didn’t get chickenpox as a kid or haven’t received the vaccine, you aren’t immune.

Impact of varicella (chickenpox) on pregnancy

Catching varicella during pregnancy increases your risk of developing pneumonia (a lung infection), which can be life-threatening. If you get chickenpox during the first 20 weeks of pregnancy, it can slightly increase the risk of serious birth defects called congenital varicella syndrome. These can cause skin scarring, stomach problems, low birth weight, and issues with the baby’s limbs, brain, and eyes. 

Becoming infected in the 5 days leading up to delivery or the 2 days after giving birth can raise your baby’s risk of getting a potentially life-threatening infection called neonatal varicella. Preterm babies born to mothers who were infected with varicella during pregnancy have a higher chance of complications. Finally, catching the virus 2 weeks before or 2 weeks after birth can lead to your baby becoming infected with chickenpox, but it’s usually mild.

How varicella (chickenpox) spreads

Chickenpox is very contagious. Someone who is infected can spread it before they develop a rash. The virus spreads through the air when an infected person coughs or sneezes. You can also get it by coming into contact with their saliva or mucus or touching a chickenpox rash.

Shingles is another sickness caused by the same virus. Having contact with someone who has shingles can result in you catching chickenpox. In rare cases, someone vaccinated against varicella can spread it to other people.

To prevent the spread of chickenpox, children are recommended to get vaccinated when they are between 12 and 15 months and then again between the ages of 4 and 6.

Symptoms of varicella (chickenpox)

The tell-tale sign of chickenpox is an itchy rash of red dots around the body that turns into blisters and then scabs. It typically begins on the chest, back, and face and then appears on the rest of the body. The rash lasts between 5 to 10 days and starts 10 to 21 days after becoming infected. 

Other symptoms of varicella include:

• Headache
• Fatigue
• Fever
• Loss of appetite

Diagnosis of varicella (chickenpox)

Doctors usually diagnose varicella with a physical examination. Your doctor may perform an additional blood test or take a swab of the rash to confirm the diagnosis.

Treatment to improve pregnancy outcomes

If you didn’t have chickenpox already it is important to get vaccinated against varicella to protect your and your future baby’s health. The varicella vaccine is administered in 2 doses. It’s not safe to receive this vaccine during pregnancy. Experts recommend waiting 3 months after you get the second dose before trying to conceive.

If you get pregnant without varicella immunity and have contact with someone who has chickenpox or shingles, let your healthcare provider know right away. Your doctor can give you an injection with medicine containing antibodies that can reduce the risk of chickenpox infection or reduce the risk of serious complications.

If you develop a chickenpox rash, you can get an oral antiviral medication that is safe during pregnancy to speed up your recovery. These are the most effective when given within the first day of the rash appearing. If you show signs of pneumonia, you may need to stay in the hospital and receive antiviral medicine through an IV.

In case you have chickenpox when you give birth, your baby can be treated with antibodies to reduce the risk of developing neonatal varicella. If your baby catches varicella in the first 2 weeks of their life, they may be treated with antiviral drugs.

• Chickenpox during pregnancy. March of Dimes. Accessed 25 November 2022.
• What are the risks associated with chickenpox and pregnancy? Mayo Clinic. Accessed 25 November 2022.