Case 44 - A 35-Year-Old at 19 Weeks’ Gestation Whose Toddler Was Diagnosed with Parvovirus

Summary

Fifth disease is the colloquial name for the common childhood exanthema erythema infectiosum. It is caused by infection with parvovirus B19, which is typically transmitted through respiratory secretions and hand-to-mouth contact. Approximately 20–25% of individuals are asymptomatic during viral replication and shedding, while others exhibit nonspecific symptoms such as fever, sore throat, headaches, and myalgias. Following antibody development, patients may develop symptoms more specific to parvovirus B19, such as the classic “slapped cheek” rash or joint pain. When pregnant women are exposed to parvovirus B19, serologic testing is performed to determine their immune status and the potential risk to the fetus. Previous infection confers lifelong immunity, but infection during pregnancy can result in transplacental transmission. Most cases of transplacental transmission resolve without complications, however, some result in nonimmune hydrops fetalis or fetal loss. When serologies are concerning for acute maternal infection, serial ultrasounds are performed to assess the fetus for signs of hydrops fetalis. Middle cerebral artery Doppler studies assess for signs of fetal anemia and potential need for intrauterine transfusion. Pregnancies complicated by hydrops fetalis should be managed at a tertiary care facility with experience in managing hydropic neonates as their resuscitation is often complicated.