When Claude Tayou Tagny was a young medical student on a rotation through clinics in rural Cameroon, he treated a woman during a difficult childbirth. She had lost, by his estimate, at least three pints of blood, triple the normal amount for childbirth and equal to roughly 30% of her total blood volume.
Tagny, with no supply of blood on hand, did the only thing he could: put out a call to the woman's family for emergency donations. He was only able to raise one pint.
"It was not enough," he says. The baby survived, but the woman did not.