I am very amused by this.

I am very amused by this. There are legitimately many scientific questions that need answering, still, about transfusion and all the random stuff that floats around in blood. Meanwhile, men shouldn't be so keen on getting women pregnant. It turns out our entire bodies then become a weapon primed for your destruction.

I may be overstating this for humorous effect. Besides, statistics are all gobbledygook, anyway, right?

[from a paper abstract]

Question Is there an association between red blood cell transfusion from female donors with and without a history of pregnancy and recipient mortality?

Findings In this cohort study that included 31,118 patients who received red blood cell transfusions, receipt of a transfusion from an ever-pregnant female donor was associated with a statistically significant increase in all-cause mortality among male recipients of red blood cell transfusions (hazard ratio, 1.13) but not among female recipients (hazard ratio, 0.99).

Meaning Receipt of red blood cell transfusion from female donors with a history of pregnancy was associated with increased mortality among male recipients; further research is needed to replicate these findings, determine their significance, and define the underlying mechanism.