Trying to make that decision now is fruitless until you have been accepted to med school and started on your pediatric residency. Then you will decide and apply for a fellowship. So do the first steps first, and see what happens, the decision may be a lot easier then.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.