Jerome,
this very thing happened to me, my daughter was born at 31 weeks of pregnancy, she was only 3 pounds, she was in intensive care trying to save her life, we were told by the doctors she needed a blood transfusion to live, we rang the local elders and told them what was going on, i was a mess as i was only 19 and this was my first child, we basically got told that there was no alternatives to blood for premature infants and that we should leave matters in jehovahs hands, i can tell you this was a very hard time for me, on one hand i wanted not to displease jehovah and on the other i didnt want my daughter to die, but we told the doctors that we wouldnt accept blood and the reasons why, they didnt make it very easy for us they kept hounding us, i remember inside thinking to myself that based on my research on this matter i knew that if the doctors felt she needed it to live they would just go ahead and give it to her( they are laws in my country) and i was thinking please dont let my daughter die, please give her blood, and boy did i feel guilty for thinking that, to cut a long story short, they gave her 20 mls of blood which would have done nothing other than to prove they had almighty power, just a side point here though, i was very very upset with the local congregation, knowing what we were going through not a single witness or even elder from the congregation came along to the hospital to give us support.