Adult Fifth Disease
Usually, there are no serious complications for a pregnant woman or her baby due to fifth disease. About 50 percent of women are already immune to parvovirus B19, and these women and their babies are protected from infection and illness. Even if a woman is susceptible and gets infected with parvovirus B19, she usually experiences only a mild illness. Likewise, her unborn baby usually does not have any problems as a result of parvovirus B19 infection.
In rare cases, however, parvovirus B19 infection can cause the unborn baby to have severe anemia and the woman may have a miscarriage (see Miscarriage After Fifth Disease).