For women who have not previously had fifth disease, contracting the illness during pregnancy can increase the risk for certain complications. Pregnant women who have been exposed to the illness should contact their health professional right away.
A very small number of pregnant women who get fifth disease will have a miscarriage.
In extremely rare cases, the infection can cause a condition called fetal hydrops, in which the fetus develops life-threatening anemia and severe swelling throughout the body. The mother and fetus should be closely monitored with fetal ultrasounds to detect this condition.
When fetal hydrops is detected, the fetus may be treated with blood transfusions while in the uterus, although this is not usually necessary. Some babies born to mothers who were infected with fifth disease during pregnancy may also be treated with blood transfusions.
Fetal parvovirus B19 infections do not cause birth defects.
WebMD Medical Reference from Healthwise