Infection can also be transmitted by blood or blood products, or across the placenta during pregnancy. If a pregnant woman develops fifth disease, she runs a one in three chance of passing the infection to her baby. Risks and symptoms. How the virus affects pregnancy depends largely on the timing of infection. When infection occurs in the first trimester miscarriage is common.
Birth defects can also occur.
In the second trimester the immune system is still immature and infections can be serious. Infections in the third trimester can be easier on the fetus because their immune response is more developed. Women who get this infection during pregnancy are followed closely with frequent ultrasounds to keep an eye on the developing baby. The odds are in your favor, but it's important to be on the safe side and check things out. If you think you've been exposed to fifth disease, get a blood test to measure your antibody levels and see if you're immune.