Human parvovirus B19 is a virus that causes slapped cheek syndrome, also known as fifth
disease. The main symptom is a rash on the face that looks like you have 'slapped cheeks'.
The virus commonly affects children. It is difficult to avoid coming into contact with parvovirus B19 because infected people do not always show symptoms (such as the rash) while they are
It is thought that 60% of adults have been infected with parvovirus B19 at some point in their lives, without showing any symptoms. Your body fights off the illness by creating antibodies against it and from then on you are immune to the virus. This means that it is unlikely that you will catch it again.
If you catch parvovirus B19 while you are pregnant, there is only a small chance of it affecting your baby. If you are infected during the first 20 weeks of pregnancy, there is an increased risk of miscarriage. If you are infected in weeks 9-20, as well as the 15% risk of a miscarriage, there is also a 3% risk that your baby will develop fetal hydrops. This is a rare, but serious condition that can cause
heart failure and anemia.
There is no routine screening test for parvovirus B19 in pregnancy. However, most pregnant women with parvovirus B19 infection usually go on to have healthy babies.
See your doctor as soon as possible if you think you have come into contact with parvovirus B19 during pregnancy. Your doctor will carry out a
blood test to look for antibodies for the virus, from a current or previous infection. There is no evidence to suggest that reinfection or reactivation will harm your baby, or that there is any increased risk of abnormality occurring in newborns.
If you test positive for parvovirus B19 in the first 20 weeks of pregnancy, you will have
ultrasound scans throughout your pregnancy to monitor your baby. If your baby develops fetal hydrops (abnormal fluid in the development of the baby), they may need a
blood transfusion to improve their chances of survival.