We get questions about fifth disease from time to time. It’s a common childhood illness that’s usually pretty mild, but if you get infected during pregnancy, it may hurt your baby. The good news is that about 6 in 10 adults (60 percent) had the infection as children and if you’ve already had fifth disease, you can’t get it again. Nonetheless, about 1 in 400 women in the United States gets infected with fifth disease during pregnancy.
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. 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. You can read about symptoms in children and adults at this link.
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, heart failure, miscarriage, or stillbirth.
You can protect yourself from getting infected by washing your hands well after being around children. Be sure to carefully throw away tissues used by children, and 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.
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.
While there is no treatment for fifth disease, there may be treatment options for problems caused in a developing baby. In rare cases of severe anemia, sometimes a provider can treat it by giving the baby a blood transfusion through the umbilical cord. If hydrops, a build up of fluid in the baby’s body, forms in the third trimester, the baby is sometimes induced and born early to receive treatment.
Again, the majority of pregnant women do not get fifth disease and, if they do, their babies are not harmed. But if you work in a day care center or are around school aged children a lot, it’s good to know about fifth disease and how to protect yourself.