Intrauterine Transfusions in Fetuses Affected by Parvovirus B19: Complications, Challenges and Outcomes

OBJECTIVE: This study evaluates the procedural characteristics, complications, and outcomes of intrauterine transfusion (IUT) for fetal anemia caused by parvovirus B19 infection during the 2023-2024 epidemic in Northwestern Europe. METHOD: This multicenter observational study included all fetuses undergoing IUT for proven parvovirus B19-induced anemia at three tertiary fetal therapy centers in Northwestern Europe. Maternal, fetal, and procedural data were collected from electronic records. Technical challenges and complications were defined a priori. Primary outcomes were procedural characteristics and complications, prenatal neurological outcomes, and perinatal outcomes. RESULTS: A total of 93 IUTs were performed in 74 fetuses. Hydrops fetalis was present in 53%. Technical challenges occurred in 24% of procedures and complications in 18%. 59% of technical challenges and 65% of complications occurred in IUTs performed in hydropic fetuses. Intracranial hemorrhage (ICH) occurred in 10% of fetuses and was associated with lower preoperative hemoglobin (2.3 ± 0.6 g/dL vs. 4.4 ± 2.2 g/dL; p = 0.006). Perinatal survival was significantly lower following IUTs with complications (64%) compared with uncomplicated procedures (91%; p = 0.013). CONCLUSIONS: IUT for parvovirus B19-related fetal anemia is technically demanding, with complication rates exceeding prior reports. Complications and challenges significantly reduce perinatal survival. These findings underscore the importance of centralizing care in high-volume fetal medicine centers with experienced operators.