Intrauterine transfusion in 103 fetuses with severe anemia caused by parvovirus infection. A multicenter retrospective study.

Background In cases of intrauterine infection, parvovirus B19 attacks hematopoietic system cells, endothelial cells, placental cells, fetal liver and heart cells by binding to the P antigen. This consecutively leads to hemolysis and red blood cell aplasia. Data on intrauterine treatment of parvovirus B19-related anemia are limited. Parvovirus B19 often affects fetuses in the early second trimester but published data is mainly from IUTs performed after 20 weeks of gestation. The aim of this study was to evaluate procedure-related complications and perinatal outcomes after intrauterine transfusion (IUT) before or ≥ 20+0 weeks of gestation in fetuses with severe anemia due to intrauterine human parvovirus B19 infection.

Materials and Methods A retrospective study investigating fetuses requiring IUT for fetal Parvo B19 infection in two tertiary referral centers between December 2002 and December 2021. Procedure-related complications, intrauterine fetal death (IUFD), and perinatal outcome were correlated to gestational age (GA) at first IUT, the presence of hydrops and fetal blood sampling results.

Results A total of 186 IUTs were performed in 103 fetuses. The median GA at first IUT was 19+3 (13+0-31+4) weeks of gestation. Up to six subsequent IUTs were required in 57/103 fetuses (55.3%). The most common access was intravascular (in the umbilical vein) in 89.8% (n=167) and the most common site of transfusion the placental cord insertion (81.7%); an intraperitoneal approach was necessary in 7% of IUTs. Intracardiac IUT was performed in six cases (3.2%) as a rescue procedure and in one case primarily due to difficult access. Peritoneal access was significantly more common in transfusions before 20+0 weeks of gestation (p=0.006). IUFD occurred in 16/103 fetuses (15.5%). Overall survival was 84.5% (87/103). Hydrops (p=0.001), lower mean hemoglobin at first IUT (p=0.001) and low platelets (p=0.002) were strongly associated with IUFD. There was no difference observed in fetuses transfused before or after 20+0 weeks of gestation.

Conclusion In the vast majority of fetuses (>80%), one or two IUTs are sufficient to bridge the time until intrauterine recovery. Overall, survival to delivery is high. IUT is a successful treatment option in fetuses affected by severe anemia due to parvovirus B19 infection in specialized centers. In experienced hands, IUT before 20 weeks is not related to worse perinatal outcome.

Publication History

Article published online:
20 June 2022