Chickenpox in Pregnancy

If you are exposed to or develop chickenpox while you are pregnant, there are a few important things you should know about how the infection could affect you and your unborn baby. There are also steps you can take to protect yourself from chickenpox before, during, and after delivery.

What Is Chickenpox?

Chickenpox is a highly contagious infection caused by the varicella-zoster virus. It is recognizable by the red, irritated blisters that appear on an infected person's skin. Chickenpox used to be a common illness, particularly in childhood. Thanks to the introduction of the varicella vaccine in the mid-1990s, however, hospitalizations related to the virus have reduced in the United States from 30.9 to 14.5 per 100,000 cases.

The most common symptom of chickenpox is a rash on the back, face, and chest that spreads quickly. Other symptoms can include fever, headache, and loss of appetite. According to the Centers for Disease Control and Prevention (CDC), a person may end up with as many as 500 blisters on their body. The virus usually runs its course within four to seven days, ending with the blisters turning into scabs.

Chickenpox is transmitted through close contact with an infected person. The blisters it causes create virus particles that are contagious when touched or inhaled. Another form of transmission may occur when an infected person exhales droplets that are then inhaled by a non-infected person.

It's also possible to contract chickenpox through contact with someone who has shingles (herpes zoster), which is also caused by the varicella-zoster virus. Shingles appears as another type of rash, but only on one side of the body or face. It occurs in people who have previously had chickenpox and the virus reactivates in adulthood.

For most people, the virus causes a benign, self-limited illness. However, when chickenpox is contracted during pregnancy, it can cause an increased risk of serious complications for the pregnant person and the baby.

Immunity

Pregnant people who have a history of chickenpox infection or who have previously been vaccinated will have antibodies to the virus. If a pregnant person with antibodies (either from the vaccine or a previous infection) is exposed to someone who has an active case of chickenpox, they shouldn't have to worry about pregnancy complications. The varicella vaccine is highly effective, and most people won't become infected twice.

It's also interesting to note that some of your antibodies will be transferred for a few weeks to your baby through the placenta, helping your child to fight off infection.

Exposure

Pregnant people who are susceptible to chickenpox (either because they have never had the infection or have not been immunized with a vaccine) are at risk of health issues for themselves and their babies. If you are pregnant and think you've been exposed to chickenpox, speak with your healthcare provider as soon as you can to discuss next steps.

Chickenpox

Pregnant people should be questioned about previous chickenpox infection or immunization at their first prenatal visit. If you are unsure whether you've ever had the virus and are concerned you may have been exposed to it, your healthcare provider can perform a blood test to check whether you've had it or have it.

It is recommended that people who are found not to have immunity to chickenpox during pregnancy (and do not contract it during pregnancy) be immunized during the postpartum period. Vaccination helps prevent the risk of future infection.

Shingles

Shingles is a condition caused by the re-activation of the chickenpox virus. It can occur at any time following the original varicella infection. After a primary (first-time) varicella infection clears, the virus remains dormant in the body. However, it can reactivate, especially when the body is immunosuppressed.

While there's not much research about the potential impact of shingles on pregnancy, a 2016 study found that of 130 people who delivered infants with congenital varicella syndrome, two of the cases were related to shingles rather than primary chickenpox infections.

Recognizing the early signs and symptoms of shingles is important for everyone, but especially pregnant people. Treatment for shingles is available and can reduce the condition's severity, but only when it is started within the first few days of illness.

Complications

About nine out of 10 pregnant people have immunity to the varicella virus because they previously have been infected with it or have been vaccinated. Although it is rare, chickenpox infection does occur in one out of every 2,000 pregnancies.

Maternal Complications

Those who do acquire chickenpox while pregnant, especially in the third trimester, are at a greater risk of developing varicella pneumonia. Varicella pneumonia is a potentially life-threatening infection of the lungs.

Pneumonia symptoms include:

• Chest pain
• Cough (possibly with blood)
• Fever
• Shortness of breath

Pregnant people with varicella pneumonia may also experience premature labor or miscarriage.

Early Pregnancy Infant Complications

There are also complications that could arise for your baby during and after pregnancy as a result of chickenpox infection. Factors depend on gestational timing.

Chickenpox infection in the first trimester of pregnancy between weeks five and 24 carries a risk of congenital varicella syndrome for the developing fetus.

Manifestations of congenital varicella syndrome may include:

• Low birth weight
• Intellectual disability
• Microcephaly (a smaller than normal head)
• Scarring of the skin
• Vision problems

Late Pregnancy Infant Complications

During the period five days before through two days after birth, a parent infected with chickenpox and presenting a rash has a three in 10 chance of passing it along to their baby. For babies whose parent has a rash between six and 21 days prior to birth, there is a smaller chance for the fetus to become infected in the womb.

Ways fetuses may contract chickenpox from their parent are through the neonatal respiratory tract or the placenta. A newborn 12 days old or younger with chickenpox will have become infected via intrauterine transmission. After this period, the presence of chickenpox indicates a post-natal infection.

Treatment

Treatment for chickenpox is available for pregnant people and for infants who were exposed in utero. Treatment approaches depend on the timing and severity of illness.

Maternal Treatment

People who acquire a primary chickenpox infection during pregnancy are commonly treated with the antiviral drug Zovirax (acyclovir), a medication that appears to have a good safety profile in pregnancy. 

It may also be possible to be treated with varicella-zoster immunoglobulin (VZIG), an antibody that provides passive immunization and protection against the virus.

Pregnant people who develop varicella pneumonia as a result of chickenpox typically require hospital admission for continuous observation and treatment with intravenous acyclovir.

Infant Treatment

Infants whose gestational parent developed varicella five days before delivery or two days following delivery are commonly treated with varicella-zoster immunoglobulin (VZIG) after birth. Newborns who develop varicella during the first two weeks of life, on the other hand, are most commonly treated with intravenous acyclovir.

A Word From Verywell

Developing or being exposed to chickenpox while you are pregnant can be very unsettling. You may have heard concerning things about how chickenpox can affect fetuses and newborns.

While there are risks to getting a varicella infection when you are pregnant, there are also medications and vaccines available to reduce these risks for both yourself and your baby. Should they occur, chickenpox infections in pregnancy can be treated.

If you are planning a pregnancy, talk to your provider about whether you have had chickenpox or received an immunization. Don't know your immune status? A blood test can be done to check. You may be tested at your first prenatal visit and you can get treated with a passive VZIG immunization if needed. Any live virus immunizations for chickenpox should be taken at least three months before you get pregnant or after your pregnancy.

If you are pregnant and have been exposed to the chickenpox virus, call your provider as soon as possible. Preventative measures are most effective when quickly employed after exposure and before any symptoms develop.