Parvovirus B19 and pregnancy

Parvovirus B19 is a widespread infection that leads to fifth disease, a mild rash illness. It’s also known as “slapped-cheek disease” because of the face rash it causes. It’s a common childhood illness but may be more serious in adults and can cause problems during pregnancy. Around 50% of adults are immune to parvovirus, usually due to an infection from childhood.

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Impact of parvovirus B19 on pregnancy

In most cases, pregnant women who become infected with parvovirus B19 have normal pregnancies and only a mild illness.

Rarely, parvovirus can lead to pregnancy loss and severe fetal anemia (but these complications happen less than 5% of the time). It may also cause birth defects that affect the central nervous system, craniofacial malformations (when the skull or facial bones fuse together abnormally), and eye problems. Finally, parvovirus infection in pregnancy is associated with hydrops fetalis (life-threatening swelling in the unborn or newborn baby).

There is a higher risk that parvovirus B19 can harm the baby if pregnant mothers get infected in the first half of pregnancy.

How parvovirus B19 spreads

Parvovirus B19 spreads just like a cold – by coming into close contact with an infected person, like when they cough or sneeze, or having hand contact. It can also spread through blood.

A pregnant mother infected with the virus can pass it on to her baby via the placenta. The virus only affects humans and thus doesn’t spread through contact with animals. Infection is most common among elementary school-age children in the winter and spring. After a parvovirus infection, you get lifelong immunity.

Symptoms of parvovirus B19

Common symptoms of parvovirus B19 infection include: 

• Fever
• Headache
• A general feeling of illness
• Muscle or joint pain
• Nausea
• Runny nose

The above symptoms typically appear 5-7 days after infection and only last for 2-3 days. People with thrombocytopenia (low platelet count in the blood) may also experience bruising. 

A few days later, a bright red rash appears on the cheeks, hands, or feet (usually, children develop the rash, not adults). By the time the rash appears, the virus is no longer contagious. About 20% of people who get infected with parvovirus B19 have no symptoms at all. 

Parvovirus B19 can cause serious complications for people with anemia (when the body doesn’t have enough healthy red blood cells) and can also lead to severe anemia. It is also more dangerous for people with weakened immune systems, such as those with HIV or who have had a recent cancer treatments or organ transplant.

Diagnosis of parvovirus B19

Parvovirus B19 infection is diagnosed via a blood test, which can show if you are immune to the virus, are not immune and have never been infected, or if you have had a recent infection.

Treatment to improve pregnancy outcomes

There is currently no vaccine to prevent becoming infected with this virus. But there are some things you can do to reduce the chance of infection if you are not immune to parvovirus B19:

• Wash your hands frequently
• Avoid close contact with sick people
• Don’t touch your eyes, nose, or mouth without washing your hands first

If, during pregnancy, you think you may have been exposed to parvovirus B19, get in touch with your healthcare provider as soon as possible. If a test shows that you have been infected, your doctor may recommend that you have more frequent checkups, blood tests, and ultrasounds to check on your baby’s health. 

In babies with hydrops or anemia, treatment with an intrauterine transfusion (supplying the baby with blood through the umbilical cord) significantly increases the chance that the baby survives the infection. 

To manage symptoms like fever, headache, or bodily aches, it’s safe to take acetaminophen (Paracetamol) during pregnancy. People who develop severe anemia due to the infection may need to stay in the hospital and get blood transfusions. If you have a weakened immune system, you may receive treatment with antibodies (immune globulin injections).  

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