Blood donations fell by just over 4% last year, according to the Irish Blood Transfusion Service (IBTS).

According to the IBTS 2013 annual report, last year, 82,697 donors gave 135,547 donations. This compares to 85,762 donors giving 141,350 donations in 2012.

The IBTS has reported a decline in the use of blood products in hospitals.

This decline in blood and platelet use, it says, has occurred much more quickly than expected, but it is a trend that is occurring throughout Europe.

The IBTS says it is unclear what the exact reasons are for the drop in blood products usage are but some of them are less waste, improved surgical techniques, reviews of transfusion practice in hospitals and less planned surgery taking place due to cutbacks in health spending.

Hospitals purchasing fewer blood products has had an impact on IBTS finances, the report points out.

"This trend looks like it will continue over the next few years and this poses a major challenge to IBTS to reduce costs even further. While there may be some scope for further reduction in costs this will not be sufficient to meet the expected reduction in income", said IBTS Chief Executive, Andy Kelly.

The IBTS says it needs to collect 3,000 donations a week, and it aims to hold about seven days supply of blood at any given time.