Most pregnant women who get slapped cheek syndrome have healthy babies. However, depending on what stage of pregnancy you’re at, there’s a small risk of miscarriage or complications for the unborn baby.
What is slapped cheek syndrome?
Slapped cheek syndrome, also known as fifth disease, is caused by a virus called parvovirus B19. The main symptom is a blotchy red rash on your face that looks like you have slapped cheeks. Other symptoms can include headache, mild fever and a sore throat. However, in about 20-30% of infections, there are no symptoms.
Slapped cheek syndrome usually affects children. Studies have shown that 60% of adults in the UK have antibodies to parvovirus B19. It’s thought that once you’ve been infected, you’ll be immune for the rest of your life.
It’s difficult to avoid contact with people who have parvovirus B19 because they may have no symptoms. Once the rash appears, the person is no longer contagious.
Complications during pregnancy
If you become infected with parvovirus B19 during your first 20 weeks of pregnancy, there’s an increased risk of miscarriage. A UK study of pregnant women estimated that parvovirus B19 caused miscarriage in 9% of pregnancies where the woman became infected in the first 20 weeks of pregnancy.
If you become infected during weeks nine to 20 of your pregnancy, there’s also a low risk that the baby will develop foetal hydrops. This is a serious condition where abnormal levels of fluid can develop in the baby, causing complications such as heart failure and anaemia. Some babies can recover from foetal hydrops. However, the condition can be fatal.
The study mentioned above estimated that parvovirus B19 caused foetal hydrops in 3% of pregnancies where the woman became infected during weeks nine to 20 of pregnancy.
There’s no evidence that infection with parvovirus B19 during pregnancy causes birth defects or development problems later in childhood.
When to get advice
See your GP or midwife as soon as possible if you’re pregnant and you think you’ve come into contact with parvovirus B19. You should do this whether you develop a rash or not. There’s no routine screening test for parvovirus B19 in pregnancy.
Your GP will do a blood test to check if you have antibodies to the virus from a current or previous infection.
If you test positive for parvovirus B19 in your first 20 weeks of pregnancy, you will have ultrasound scans throughout your pregnancy to monitor your baby. If your baby develops foetal hydrops, they may need a blood transfusion while still in the womb.
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