Prophylactic exchange transfusion in sickle cell disease pregnancy: a TAPS2 feasibility randomized controlled trial

Serial prophylactic exchange blood transfusion (SPEBT) is increasingly used in sickle cell disease (SCD) pregnancy, despite a lack of robust evidence. The Transfusion Antenatally in Pregnant Women with Sickle Cell Disease (TAPS2) study assessed the feasibility and acceptability of conducting a definitive randomized controlled trial of SPEBT (intervention) vs standard care (control) in this population. Women aged ≥18 years with SCD, between 6+0 and 18+6 weeks of singleton gestation, were randomized 1:1 every 6 -10 weeks throughout pregnancy in 7 hospitals in England. The main outcomes were recruitment rate (primary outcome), acceptability, and retention. Secondary outcomes were safety and maternal/infant outcomes. In total, 194 women were screened over 42 months (extended because of the pandemic), 88 were eligible, and 35 (39.8%) consented to participate; 18 participants were randomized to intervention, and 17 to control. Follow-up data were collected on all participants. Twelve patients in the intervention group received at least 1 SPEBT, of these, 11 received ≥3. The remaining patient was withdrawn from SPEBT because of transfusion reaction. Sixteen control participants required at least 1 transfusion. There were no statistically significant differences in maternal, infant, and postnatal outcomes. A trend toward a lower incidence of vaso-occlusive crisis, preterm delivery, and improved birthweight was observed in the intervention. The study achieved satisfactory recruitment and retention, confirming its acceptability to participants. TAPS2 demonstrates that it is feasible to perform a definitive international trial of SPEBT in SCD pregnancy. These trials were registered at www.ClinicalTrials.gov as #NCT03975894 and International Standard Randomized Controlled Trial Number (www.isrctn.com; #ISRCTN52684446).