Parvovirus Infection in Pregnancy

What is parvovirus? 

Parvovirus B19 is a common virus that usually causes a mild childhood illness called “slapped cheek syndrome.” In children, it often causes a red rash on the cheeks and sometimes a mild fever. In adults, including pregnant women, it may cause no symptoms or just mild flu-like symptoms such as tiredness, mild fever, or joint aches. Most people recover completely and develop immunity. 

If a pregnant woman who has never had the infection before catches parvovirus, the virus can pass to the baby. Most of the time, this does not harm the baby. However, in rare cases, especially early in pregnancy, it can cause problems such as low red blood cells in the baby (fetal anemia), swelling in the baby (hydrops fetalis), or, very rarely, loss of the pregnancy. 

What causes parvovirus?

Parvovirus is spread through coughs, sneezes or close contact with someone infected. It is common in schools and childcare settings. Most adults have already had it and are immune. Pregnant women can pass it to the baby if they get infected. 

How is parvovirus diagnosed?

If you’ve been exposed or have symptoms, a blood test can check whether you are immune or recently infected. If infection is confirmed, ultrasound scans will be offered to monitor your baby for signs of anaemia or other problems. 

What does it mean for my baby?

In a small number of cases, the virus can cause the baby to become anaemic, which may lead to heart strain or fluid build-up (hydrops). If detected early, treatment such as a blood transfusion before birth can be offered. Most infections in pregnancy do not cause problems, but the risk is higher if infection happens in the first half of pregnancy. 

What happens next?

You will be offered regular scans over the next few weeks to check your baby’s health. Most pregnancies continue normally, and many babies are not affected. If problems are found, a specialist team will offer treatment and close monitoring. 

Will it happen again?

If you’ve had parvovirus once, you are very unlikely to get it again. In future pregnancies, you would not need special testing unless new symptoms appear.