What is the impact of whole-blood donation frequency on donor health? A systematic review
30/03/26
Globally, tens of millions of donors provide approximately 118.5 million whole blood donations each year. These donations are of utmost importance to maintain the blood supply, used for a wide range of clinical applications such as emergency blood transfusions. A possible strategy to maintain blood levels is to increase the donation frequency of existing donors. But at what frequency can donors safely donate whole blood without any adverse effects on their own health? That was the question we tried to answer in one of our recently published systematic reviews.
A systematic search in three databases resulted in four records on three randomized controlled trials (RCTs), investigating the impact of increased donation frequency on adverse events, iron status, and haematological parameters in whole blood donors.
The key findings of our systematic review were:
- Shorter inter-donation intervals (8 or 10 weeks for men and 12 or 14 weeks for women), compared to whole-blood donation every 12 (men) or 16 (women) weeks, might result in decreased haemoglobin and ferritin levels, increased low-haemoglobin deferral and increased reporting of tiredness, fainting, dizziness and restless legs. For other, and more serious clinical outcomes, no differences were found.
- Lower haemoglobin and ferritin levels may also be seen in repeat male donors at a 12‑week inter‑donation interval after two or three donations.
When interpreting these results, it is important to consider that the identified evidence was of low to very low certainty, due to limitations in study design and imprecision. Therefore, future high-quality RCTs, comparing shorter to longer inter-donation intervals over a longer period of time, are needed to confirm these results and to identify the most optimal inter-donation intervals for both men and women, balancing the stability of the blood supply and the health of the donor.
Read the published full systematic review in Vox Sanguinis.
