Parvovirus B19 Infection in Pregnancy: Awareness of the Increased Incidence of Severe Intrauterine Infection

In 2024, Europe experienced a significant upsurge in cases of Parvovirus B19 (B19V), the etiological agent of erythema infectiosum, also known as fifth disease. The prevalence of B19V in pregnant women, a particularly vulnerable population, holds critical clinical significance. Typically, B19V follows a well-documented seasonal pattern, with annual epidemics peaking in the spring and larger outbreaks occurring approximately every four years. B19V exhibits a tropism for erythroid precursor cells, potentially resulting in fetal anemia and, in the most severe scenarios, intrauterine demise. Severe in utero infections necessitate intrauterine erythrocyte transfusion (IUT), a highly specialized and technically demanding procedure that is exclusively performed in tertiary-level prenatal care units. This study delineates how the notable increase in B19V infections is also reflected in our prenatal diagnosis unit at Fondazione Policlinico Agostino Gemelli (FPG) IRCCS, Rome, Italy. According to our case series, since 2018, B19V has been identified as the second most common cause of fetal anemia during the study period (29%, 6 patients), yet it accounted for the majority of IUT procedures performed in 2024 (16 out of 19 cases, 84.2%). Given the rising incidence of severe intrauterine infections in recent epidemic cycles, healthcare professionals should maintain a high index of suspicion regarding the clinical manifestations of maternal B19V infection and its potential obstetric complications. Further research is imperative to evaluate the cost-effectiveness of routine screening for B19V immunity in pregnant women and to investigate the long-term neurodevelopmental and clinical outcomes of neonates affected by intrauterine B19V infection.