Is fifth disease fatal for fetuses?

Usually not: Fatality is low, 2-6%. Infected fetus can develop hydrops fetalis(severe edema), growth retardation, and congenital anemia.

Possible: Fifth disease is a common childhood ailment that is generally experienced by school age in most. It is usually quite mild & passes without problems. If a girl was not infected as a child & experiences it while pregnant, the virus can result in miscarriage or fetal death.The defining event appears to be a variable effect on babies ability to form blood cells. If it slows it, death can result.

Primary infection: with Parvovirus B19 is usually benign, but can cause fetal anemia, non-immune fetal hydrops - fluid in at least 2 areas: under the skin, in the abdomen, in the sacs around the lungs or heart or in the placenta. Fetal demise may occur any time. Pregnant women exposed to 5th Disease need Parvovirus-specific IgG & IgM titers drawn a week apart &, if infected, referral to a fetal-maternal specialist.