COMPARATIVE ASSESSMENT OF HAEMATOLOGICAL PARAMETERS AMONG FIRST-TIME AND REPEAT BLOOD DONORS: A CROSS-SECTIONAL STUDY

Abstract

Background: Repeated blood donation can cause recurrent red cell loss and may progressively affect iron availability and erythropoiesis. Although haemoglobin is routinely used for donor screening, changes in red cell indices may occur before clinically evident anaemia. This study aimed to assess selected haematological parameters among first-time and repeat blood donors and to evaluate their relationship with donation frequency. Materials & Methods: This cross-sectional study was conducted among 200 voluntary male whole-blood donors at a tertiary-care hospital blood centre from October 1, 2023, to March 31, 2024. All prospective blood donors were screened according to the donor selection criteria given by the National Blood Transfusion Council, Director General of Health Services, Ministry of Health and Family Welfare & Government of India, and only donors who fulfilled all eligibility criteria and were found fit for donation were included in the study. Female donors and donors receiving iron supplementation were excluded. Donors were categorised according to the number of previous donations during the preceding five years into four groups: first-time donors (n=100), 2–5 donations (n=40), 6–10 donations (n=28), and >10 donations (n=32). Complete blood count parameters, including haemoglobin, hematocrit, RBC count, MCV, MCH, MCHC, RDW, WBC count, platelet count, MPV, and PDW, were analysed using an automated haematology analyser. First-time and repeat donors were compared, and differences across the four donation-frequency groups were assessed using an independent-samples t-test and one-way ANOVA with Tukey’s post-hoc analysis. Correlation analysis was used to assess the relationship between donation frequency and selected red cell indices. Results: Repeat donors demonstrated a significantly lower mean MCV compared with first-time donors (84.9 vs. 91.2 fL; mean difference, 6.3 fL; 95% CI, 2.9–9.6; p<0.001). Mean RDW was significantly higher among repeat donors (14.5% vs. 12.9%; mean difference, 1.45; 95% CI, 1.01–2.03; p<0.001). Across the four donation-frequency groups, MCV showed a progressive decline from 91.2 ± 4.5 fL among first-time donors to 83.7 ± 3.8 fL among donors with >10 previous donations, whereas RDW increased from 12.9 ± 1.1% to 14.5 ± 1.4%, respectively. ANOVA demonstrated significant differences in both MCV and RDW across the groups (p<0.001). Tukey’s analysis showed significant differences, particularly between first-time donors and those with ≥6 previous donations. No significant differences were observed in MCH, MPV, WBC count, or platelet count between first-time and repeat donors. Conclusion: Repeat blood donors demonstrated significant changes in red cell indices, characterised by lower MCV and higher RDW, with progressively greater changes observed with increasing donation history. These findings may indicate altered erythropoiesis associated with repeated blood donation and could precede clinically evident anaemia. However, because biochemical markers of iron status were not assessed, iron deficiency cannot be confirmed from these findings alone. Routine monitoring of haemoglobin and red cell indices, particularly among frequent donors, together with appropriate donor counselling and follow-up, may help support long-term donor health and a safe, sustainable blood supply.