Fifth disease and pregnancy

Fifth disease is a common childhood illness that’s usually pretty mild. But if you get infected during pregnancy, it may hurt your baby.

What causes fifth disease?

Fifth disease is caused by a virus called parvovirus B19. It’s called fifth disease because many years ago, it appeared fifth in a list of common causes of childhood rash and fever. It usually spreads through the air from an infected person's cough or sneeze.

What problems does fifth disease cause in pregnancy?

Most unborn babies are not harmed if their mother gets fifth disease. But some babies do become infected. The virus can make it hard for babies to make red blood cells, which can lead to:

  • A dangerous form of anemia. Anemia is when you don’t have enough healthy red blood cells to carry oxygen to the rest of your body.
  • Heart failure
  • Miscarriage, when a baby dies in the womb before 20 weeks of pregnancy
  • Stillbirth, when a baby dies in the womb after 20 weeks of pregnancy

What are the symptoms of fifth disease?

Symptoms in children include:

  • A rash on the face that looks like a slapped cheek. Rash also can appear on a child’s arms, legs and torso (trunk of the body). Rash is the most common sign in children.
  • Fever
  • Headache
  • Sore throat
  • Joint pain

Infected adults often have pain and swelling in their joints and sometimes mild flu-like symptoms. Adults usually don’t get a rash. Symptoms in both children and adults generally appear between 4 and 21 days after infection.

If you think you’ve come in contact with fifth disease or have symptoms that may be caused by it, tell your health care provider immediately. If you have a rash, your health care provider may be able to diagnose fifth disease during a physical exam. If you don’t have a rash, blood tests can help determine if you have fifth disease.

Who is at risk of getting fifth disease?

People with young children and who work with children (such as child care providers and teachers) are most likely to come in contact with fifth disease and get infected.

How can you avoid fifth disease during pregnancy?

Here are some ways to protect yourself from getting infected:

  • Wash your hands well after being around children.
  • Carefully throw away tissues used by children.
  • Don’t share drinking glasses, cups, forks or other utensils with anyone who has fifth disease or who is in contact with someone who has fifth disease.

How is fifth disease treated?

There is no treatment. Fifth disease usually is mild and goes away on its own.

If you’re pregnant and become infected, your health care provider monitors your pregnancy carefully for problems with your baby. He may recommend that you have an ultrasound once a week or every other week for 8 to 12 weeks. If ultrasound doesn’t show any problems, you don’t need any more testing.

If an ultrasound shows that your baby is having problems, your provider may recommend amniocentesis to confirm the infection. If your baby has fifth disease, chances are the infection will go away on its own. Your provider may monitor your baby’s health during routine prenatal care visits.

Fifth disease causes severe anemia in the babies of fewer than 5 percent of infected pregnant women. Severe anemia can cause hydrops, a buildup of fluid in your baby’s body. Hydrops can lead to a baby’s heart failure and death. If an ultrasound shows that your baby has hydrops, your provider may use a special procedure called cordocentesis to check the severity of your baby’s anemia. During this test, your provider inserts a thin needle into an umbilical cord vein to take a small sample of your baby’s blood for testing.

If your baby has severe anemia, your provider may be able to treat it by giving her a blood transfusion through the umbilical cord. Blood transfusion is having new blood put into your body. In most cases, the anemia isn’t severe and your provider may simply monitor your baby for any new health problems before birth.

If your baby has hydrops from fifth disease during the third trimester, you may need to be induced to give birth early. Your provider can talk to you about birth and treatment options for your baby.

How common is fifth disease?

About 6 in 10 adults (60 percent) had the infection as children. If you already had fifth disease, you can’t get it again.

About 1 in 400 women in the United States gets infected with fifth disease during pregnancy.

Last reviewed: March, 2012