Are female blood donors riskier than men? A new study challenges past fears

A study published in the New England Journal of Medicine is challenging long-held assumptions that blood donations from women carried a higher risk of death for recipients.

Patients who receive blood donations face no greater risk of death whether the blood comes from a man or a woman, according to new research that is challenging long-held assumptions.

A study published in the New England Journal of Medicine Wednesday found there was no difference in the overall survival rates between recipients of male donor blood and recipients of female donor blood.

Until now, the thinking has been that those who get female donor blood may face a higher risk for a number of reasons.

The clinical trial conducted at The Ottawa Hospital enrolled roughly 9,000 patients over a two-year period from 2018 to 2020.

“Our randomized trial determined that there actually is no difference between male and female donor blood across the board … in all types of recipients, from surgical to medical to ICU to outpatient patients,” said Dr. Dean Fergusson, senior scientist at The Ottawa Hospital and professor at the University of Ottawa.

Some previous observational studies have suggested that there is a higher risk of death following blood transfusions from women, especially those who have a history of pregnancy, compared to men.

Fergusson, who co-authored the NEJM study, said it was thought that differences in hormone levels, antibodies and iron levels would result in a greater benefit from receiving male blood over female blood.

The hypothesis is that previous pregnancies that carry over antibodies to the blood could impact the immune response of the recipient as well as the inflammatory response from receiving blood, he said.