Human parvovirus B19 (erythema infectiosum), in the context of an acquired infection while pregnant, is typically a mild viral syndrome that may include a rash, fever, chills, headache, myalgias, arthralgias, nausea, vomiting, abdominal cramping, diarrhea, or mild respiratory symptoms. The rash seen in adult human parvovirus B19 infection is variable in distribution, less likely to demonstrate the characteristic red cheek appearance seen in children, and may not be present at all. It is generally self-resolving and seldom carries a significant burden of morbidity in otherwise healthy people. There may be consequences of maternal human parvovirus B19 infections for the developing fetus, however, especially if the infection is acquired in the second or third trimester. Human parvovirus B19 has a tropism for bone marrow and infects erythroid progenitor cells, which can cause fetal anemia. Fetal anemia may present as fetal tachycardia, high-output heart failure, hydrops fetalis, and death. Parvovirus is also a potential cause of fetal myocarditis. This pregnant patient has been exposed to parvovirus via her 5-year-old son, and because symptoms are mild and may go unnoticed, determining whether she has been infected through measurement of serum-specific IgG and IgM concentrations is the most appropriate next step in management. Increased concentration of IgG in the absence of IgM indicates a previous infection, while increased concentrations of both indicate a current or recent infection. Determining whether or not this patient has been infected will help guide further management of her pregnancy, including the need for additional testing or sonography.
Most adults with parvovirus B19 infection are asymptomatic (or associated with nonspecific flulike symptoms or arthralgias); however, parvovirus B19 during pregnancy can have devastating fetal consequences due to viral cytotoxicity to fetal erythrocyte precursors. With increasingly severe fetal anemia, the fetal heart tries to compensate for hypoxemia by increasing cardiac output. However, eventually it cannot compensate, and high-output fetal heart failure develops. As with other cases of heart failure, fetuses develop third spacing of fluid, resulting in ascites (ie, tense fluid-filled abdomen) and generalized skin edema (and subsequent peeling). Other clinical features include pleural or pericardial effusions and placental edema.
<aside> 💡 Pregnant women should avoid infected individuals because the virus can cross the placenta and have devastating fetal consequences.
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Parvovirus B19, in the context of an acquired infection while pregnant, is typically a mild viral syndrome that may include a rash, fever, chills, headache, myalgias, arthralgias, nausea, vomiting, abdominal cramping, diarrhea, or mild respiratory symptoms. The rash seen in adult parvovirus B19 infection is variable in distribution, less likely to demonstrate the characteristic red-cheeked appearance as in children, and may not be present at all. It is generally self-resolving and seldom carries a significant burden of morbidity in otherwise healthy persons. There may be consequences of maternal parvovirus B19 infections for the developing fetus, however, especially if the infection is acquired in the second or third trimester. Parvovirus B19 has a tropism for bone marrow and infects erythroid progenitor cells, which can cause fetal anemia. Fetal anemia may present as fetal tachycardia, high-output heart failure, hydrops fetalis, and death. Parvovirus is also a potential cause of fetal myocarditis.