CD28 and hydrops fetalis: 99 (0.98–1.00)], resting Treg%CD4 [OR (95% CI): 0.98 (0.97–0.99)], CD28 on CD39+ activated Treg [OR (95% CI): 0.98 (0.96–1.00)], CD45RA on CD39+ resting Treg [OR (95% CI): 0.97 (0.94–1.00)] were protective against HF.