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According to new study, males transfused with blood from a woman with a history of pregnancy appear to be 13 percent more likely to die compared with those who received blood from man. The highest risk seemed to be in men 18 to 50 years old. They had a 50 percent increased risk of death after receiving blood from a previously pregnant female, the risk remained increased for many years after transfusion.
No such increase was observed for female recipients, or for male recipients over 50 years. Pregnancy might affect a woman’s immune system in some way that makes her blood more risky for a man. However, the risk is unlikely to prompt any immediate change in blood donation policies.
The study focused on patients data that received blood transfusions from – men, never-pregnant women and women who’d been pregnant. After receiving a single transfusion, the three-year death rate among men was 13.5 percent for those who received male blood, 13.1 percent for those who got never-pregnant female blood, and nearly 17 percent for those who received blood from a previously pregnant female.
U.S. blood centers sometimes exclude women with a history of pregnancy from donation of blood products like platelets or plasma, due to a condition called transfusion-related acute lung injury (TRALI). TRALI typically occurs within six hours of a transfusion, and between 5 to 25 percent of patients who develop the condition die from it, according to the U.S. National Heart, Lung, and Blood Institute.
TRALI is thought to be caused by antibodies that women develop through exposure to fetal blood during pregnancy. It has been associated specifically with previously pregnant female donors, the researchers said.
However, those antibodies aren’t what caused the death risk found in this new study, which stretches out for years.
Pregnancy might make a lasting change to the immune system of a woman, because she has to tolerate a foreign object in her body for nine months,
There is a lot of immune regulation involved in making a pregnancy possible, some of this suppressive regulation could last long after the pregnancy.
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