Background: Temporary blood donor deferral may interrupt subsequent donor participation. Structured follow-up may provide an opportunity for donor re-engagement and reassessment of eligibility. This study evaluated the implementation and donor re-entry outcomes of a structured donor re-engagement programme incorporating cause-specific recall and telephonic follow-up.

Methods: A prospective implementation study was conducted from January to June 2026 at a tertiary-care teaching hospital blood centre in India. Temporarily deferred donors who consented to follow-up received cause-specific counselling, scheduled telephone reassessment, and targeted interventions where appropriate. The primary outcome was successful donor re-entry, defined as whole-blood donation at the study blood centre following temporary deferral and programme enrolment. Donations reported at other centres were recorded separately.

Results: Among 2,345 donors screened, 1,760 (75.1%) donated, 518 (22.1%) were temporarily deferred, and 67 (2.9%) permanently deferred. Of the temporarily deferred donors, 451 (87.1%) enrolled in the programme. Successful re-entry occurred in 223/451 (49.4%). Re-entry varied by deferral category: inadequate sleep, 71/88 (80.7%); elevated blood pressure, 21/34 (61.8%); low haemoglobin in males, 32/60 (53.3%); antibiotic therapy, 19/43 (44.2%); menstruation, 26/62 (41.9%); poor venous access, 17/42 (40.5%); and low haemoglobin in females, 37/122 (30.3%). A further 16/451 (3.5%) reported donation elsewhere.

Conclusion: The structured donor re-engagement pathway was feasible to integrate into routine blood-centre practice. Approximately half of enrolled temporarily deferred donors subsequently donated at the study centre. Given the absence of a comparator and limited long-term follow-up, these findings represent donor re-entry outcomes rather than evidence of a causal effect on retention.