Chickenpox, also known as varicella, is an infectious disease. Chickenpox is highly contagious and spreads from person to person by direct contact or through the air from an infected person’s coughing or sneezing. A person with chickenpox is contagious 1-2 days before the rash appears and until all blisters have formed scabs. It takes from 10-21 days after contact with an infected person for someone to develop chickenpox. Pregnant women who get chickenpox are at risk for serious complications. For example, 10-20% of pregnant women who get chickenpox develop pneumonia, with the chance of death as high as 40%.
If a pregnant woman gets chickenpox while in the first or early second trimester of pregnancy, there is a small chance (0.4 – 2.0%) that the baby could be born with birth defects known as "congenital varicella syndrome." Babies born with congenital varicella syndrome may be of low birthweight and have scarring of the skin and problems with arms, legs, brain, and eyes.
Newborns whose mothers develop chickenpox rash from 5 days before to 2 days after delivery are at risk for chickenpox shortly after birth, with the chance of death as high as 30%.
- All pregnant women should talk to a healthcare provider to determine if they are protected against chickenpox. For pregnant women, any of the following are evidence of protection against chickenpox:
- Documentation of two doses of varicella vaccine
- Blood test showing immunity to varicella
- Diagnosis or verification by a health care provider of a history of chickenpox or herpes zoster, also known as shingles
- If a pregnant woman has never had the chickenpox, the best way to protect against chickenpox is to get the chickenpox vaccine. However, women should not receive the chickenpox vaccine during pregnancy. As soon as a pregnant woman who is not protected against chickenpox delivers her baby, she should be vaccinated against chickenpox. The first dose of vaccine can be given before she leaves the hospital, and the second dose at the 6-8-week post-partum visit. The vaccine is safe even for mothers who are nursing.
- Women who are thinking about getting pregnant but are not protected against chickenpox should get vaccinated at least one to three months before becoming pregnant. Women should not get vaccinated during pregnancy or during the 30 days before becoming pregnant.
- If a pregnant woman is not protected against chickenpox, people who live with her should be protected. If close contacts have not already had chickenpox, vaccination of these contacts is the most effective way to protect a pregnant woman against chickenpox
- Pregnant women should stay away from anyone who has chickenpox. This includes people who have been vaccinated and then get a very mild form of chickenpox, sometimes called "breakthrough" chickenpox (usually little or no fever and fewer than 50 skin lesions). "Breakthrough" chickenpox is still contagious.
- If a pregnant woman is not protected against chickenpox and finds out that she has been in contact with someone who has chickenpox, she should call her doctor immediately.
Chickenpox rash usually appears first on the face and top half of the body, but can spread over the entire body causing 250-500 itchy blisters in people who have never been vaccinated against chickenpox. In people who have been vaccinated, the rash can be quite mild, such as only a few spots that look like mosquito bites.Chickenpox illness lasts about 5-10 days. Other symptoms include high fever, severe itching, uncomfortable rash, dehydration from vomiting or diarrhea, headache, infected skin lesions, worsening of asthma or more serious complications such as pneumonia.
Certain groups of persons are more likely to have more serious illness with complications. These include adults, infants, adolescents and people with weak immune systems from either illnesses or from medications, such a long-term use of steroids.
Serious complications from chickenpox include bacterial infections which can involve many sites of the body including the skin, tissues under the skin, bone, lungs (pneumonia), joints and the blood. Other serious complications are due directly to the virus infection and include viral pneumonia, bleeding problems and infection of the brain (encephalitis).