Restrictions on donors are sometimes called "deferrals", since blood donors who are found ineligible may be found eligible at a later date.
Advocates for change to MSM prohibitions point out that screening of donors should focus on sexual behavior as well as safe sex practices since many MSM may always have protected sex, be monogamous, or be in other low risk categories.
Some groups in favor of lifting the restrictions support a waiting period after the blood is donated when the donor is considered to have had behavior considered higher risk, and before it is used, to match the blood bank's window of testing methods.
Italy, Latvia, Poland, Russia and Spain are the only European countries that don't discriminate when it comes to blood donation.
The donation is allowed if the donor hasn't had a risky sexual encounter, but not depending on the sexual orientation of the donor.
The UK since November 2017 has implemented a 3 month deferral policy on all gay/bi men who want to donate their blood, the lowest in the western world.
However this does not apply to Northern Ireland, which still has a 12 month deferral period in place.
The Advisory Committee on the Safety of Blood, Tissues and Organs recommended the policy change after a study concluded that a total ban may breach equality legislation and that the risk of HIV reaching the blood supply would only increase by approximately 2%.
In Ireland, Men who have sex with men (MSM) may donate blood if they have not engaged in oral or anal sex with another man at least 12 months prior to a donation. On 27 July 2015, Tomás Heneghan, a 23-year-old University of Limerick student and journalist from Galway began a legal challenge in the High Court against the permanent deferral imposed on MSM donors.
He argued that the questionnaire and interview process used by the IBTS does not adequately assess the risk of disease transmission posed by his donation. He said that both failed to consider the length of time between a donor's last sexual experience and the end of a "window period" in which infections are sometimes not detected.