Treatment of Twin Anemia Polycythemia Sequence with Donor Transfusion and Partial Recipient Exchange Transfusion: Procedural Considerations and Outcomes.

Intrauterine transfusion (IUT) of the donor and partial exchange (pET) of the recipient is a temporizing treatment for pregnancies with Twin Anemia Polycythemia Sequence (TAPS). We aimed to provide a detailed description of the procedural approach and outcomes for sequential donor IUT and recipient pET in TAPS. Retrospective study of spontaneous TAPS referred to the Johns Hopkins Center for Fetal Therapy treated with donor IUT followed by recipient pET utilizing a double-syringe setup. Procedural characteristics and outcomes as well as the accuracy of existing transfusion formulas were analyzed and compared with the literature. 5 of 78 patients with spontaneous TAPS underwent a total of 19 combined IUT/pET procedures (median first procedure to delivery interval 5.6 weeks [interquartile range IQR 1.9-6.0]). One pET was stopped due to fetal deceleration. The patients were delivered at 33.0 weeks [IQR 31.9-33.3] with two survivors and no neonatal transfusion requirements. The IUT volume was 48 mL [IQR 39-63 mL] and the pET volume was 32 mL [IQR 20-50], utilizing aliquots of 5-20 mL for the latter ( = 0.021). For the IUTs, the assumption of a fetal blood volume below 150 mL/kg underestimated the required transfusion volume. For the pETs, all formulas required adjustment of the dilution volume based on bedside testing ( < 0.05 for all). Donor transfusion followed by partial exchange in the recipient can prolong pregnancy in spontaneous TAPS and obviate the need for neonatal transfusion. A double-syringe setup facilitates efficient saline exchange. Because the accuracy of volume formulas is limited, bedside testing is recommended to achieve the target hemoglobin.