A study involving 31,118 patients has recently found that men who received blood from women who had been pregnant had a higher risk of dying after the transfusion. A team of scientists from Sanquin Research found that this fatal phenomenon was only present in men, not other women. The study was performed in the Netherlands and included individuals who had received 59,320 red blood cell transfusions from 2005 to 2015. The results were drastically different between Male And Female recipients.

The study

Of the 31,118 patients who had received Blood Transfusions between 2005 and 2015 in the Netherlands, 3,969 died.

The leading cause of death was said to be acute lung related injuries directly associated with the transfusion.

Furthermore, scientists found that men over the age of 50 were 1.5 times more likely to die if they had been given blood from a woman who had been pregnant. The study showed that these men would typically sustain acute lung injuries within three years of the blood transfusion.

For female recipients, the case was not the same. Women showed no signs of developing lung injuries after receiving blood from women who had been pregnant. The "Journal of the American Medical Association" recently published the entire study.

Why are men more likely to die?

Although more research is needed to discover the reason behind the significant increase in male deaths in this case, Dr.

Rutger Middelburg told "The Telegraph" that this may be due to the antibodies that women develop during pregnancy. These "immunologic changes" that women undergo while they are pregnant may prove to be fatal for men.

An alternative theory is that there is a significant physiological difference between male and female blood, which may cause a higher mortality rate in men who receive blood transfusions from women who have been pregnant.

However, no association between women dying after receiving men's blood has been made. In order to truly determine the clinical significance of antibodies produced by pregnant women, more research is needed.

What does this mean for women?

The National Health Service in the United Kingdom has not changed its policy on blood donations.

All donors are welcome at this point in time, including women who have been pregnant. However, whether or not these findings will have any implications on blood donations in the future is unclear. Research is still currently underway.