(539) Clinical characteristics and outcomes of intrauterine blood transfusion (IUT) for infectious etiologies

Objective: Congenital viral infectious may result in fetal anemia and thrombocytopenia. While intrauterine blood transfusions (IUTs) are more commonly performed for Rh disease, studies have reported the utilization of IUT for this indication with varying success. Our primary objective was to characterize outcomes of patients undergoing IUT for infectious etiologies at our center compared to Rh disease.

Study Design: This was a retrospective cohort analysis of patients who underwent IUT at our fetal center from 2012-2023. Infectious etiologies were identified by maternal serologies and confirmed by amniotic fluid PCR. Clinically relevant outcomes were obtained from electronic medical records. Statistical analysis was performed using GraphPad Prism 9.

Results: During the 12-year study period, 70 patients underwent IUT at our center, 34% (24/70) for Rh disease and 17% (12/70) for infectious etiologies. The remaining causes varied and were excluded from this study. Within the infectious etiology cohort, 7/12 (58%) were for parvovirus and 5/12 (42%) for CMV. Compared to Rh disease, those with infectious etiologies were more likely to be diagnosed at earlier gestational ages (22 [20, 24] vs 25 [22, 28] weeks, p=0.04), present with hydrops (75 vs 33%, p=0.03), have lower fetal platelets (27 ±33 x10^3 vs 163 ±112 x10^3, p< 0.01) and have a fewer number of procedures (2 [1, 2] vs 5 [2, 6], p< 0.01). Perinatal death was significantly greater in cases of CMV (4/5, 80%) when compared to parvovirus (1/7, 14%) or Rh disease (5/24, 21%) (p=0.02).

Conclusion: Fetal infectious etiologies may be an indication for IUT, but are associated with earlier gestational age at presentation, development of hydrops and, in the case of CMV, significantly greater rates of perinatal death when compared to IUT performed for Rh disease. In contrast to Rh disease, significant fetal thrombocytopenia was noted in both CMV and parvovirus infectious, yet perinatal outcomes for CMV were significantly worse. Patients should be counseled on the various outcomes and implications by indication.