Wow, that's an interesting question, and I have heard it from many a new mom who's baby needs blood work and here they are taking tubes of blood out of your baby and your going WOW, how much could there be, "DON'T TAKE IT ALL" and you should advocate for your infant when blood is being taken, ask, do you really need that much for this test? ;=) The answer is that blood makes up 7% of your total body mass, adult or infant, it doesn't matter. So for instance, a 64kg (141lb) adult would have 4.5 kg, or 4.4 liters of blood. So a 10lb infant would have a volume of .7lbs so .7 of a pint of blood (average) for a 10lb infant.



