Blood transfusion danger: Donations by pregnant women increase mortality in men

Blood donations are usually life-savers, but new research reveals that men who receive blood from women who have been pregnant are at risk of premature death from an adverse immune response called transfusion-related acute lung injury that occurs some time after the donation. The discovery further puzzles researchers as it apparently has no effect on women receiving blood from once-pregnant women.

TRALI, or transfusion-related acute lung injury, is a rare but life-threatening adverse effect of the transfusion of blood and blood components, characterized by sudden acute respiratory distress. The symptoms of TRALI typically develop during or within six hours after blood product administration. It may unlikely be entirely prevented, but its frequency may be reduced by hospitals providing proper procedures in place such as guidelines on blood utilization and conservation.

Researchers from Sanquin Research in Leiden, the Netherlands, found that 13 percent of the 31,118 patients analyzed died after receiving female donors’ blood. These patients received 59,320 blood transfusions across six hospitals between 2005 and 2015. The researchers evaluated three donor categories – male donors, female donors who had been previously pregnant (ever-pregnant), and female donors who had never been pregnant (never-pregnant). The findings reveal that the deaths are highly likely to occur in men receiving blood from a previously pregnant woman compared to a male donor. (Related: Do Nearly All Pregnant Women Have Dangerous Levels of Pollutants In Their Blood?)

“Among patients who received red blood cell transfusions, receipt of a transfusion from an ever-pregnant female donor, compared with a male donor, was associated with increased all-cause mortality among male recipients but not among female recipients,” according to the researchers.

Study author Dr Rutger Middelburg admitted that the study requires further investigation to determine the cause and clinical significance of the male-specific phenomenon; while the study shows an apparent correlation, it still doesn’t explain why such an effect occurs from blood donated by ever-pregnant women.

Professor Kevin McConway, from The Open University, brushed off the implication of the study: “I’m a man, and I wouldn’t be concerned.”

“Even if the effect on mortality is real, all the data come from the population of the Netherlands, and things may work differently in populations with different genetic backgrounds,” McConway added. “For all these reasons and others, it’s important not to read too much into this study, and I don’t think there is yet any real cause for men to be particularly concerned about this issue if they need a blood transplant.”

A spokesman for NHS Blood and Transplant said: “Blood donations from all our donors are lifesaving, and we continue to encourage donations from women who have previously been pregnant.”

Information on the sex of the donor is not currently provided to hospitals or patients, but it is possible in the future to separate out blood by the gender of the donor, as each donation is tracked from donor to recipient.

The study was published in the Journal of the American Medical Association.

Sources include:

DailyMail.co.uk

BloodJournal.org

ScienceAlert.com

JAMANetwork.com