I'm playing a reformed celtic character in a duchy level broken world. It's been about 37 years in game since I'm started and I'm sick and tired of 4/5ths of my children dying to either "an accident" or an infected wound due to mysteriously becoming wounded before they've turned 16. I've looked at others with the celtic religion both reformed and not and it's the same across france and iberia. Just about every child dead of an accident or an infected wound and nearly all the rest having one eye, a hook hand or a peg leg. All other religions don't have nearly this amount of dead children, usually less than a quarter dead and usually to illness. My best guess is some event exclusive to celtic children that either kills or wounds them strikes far too often to be balanced. It's almost enough to kill off entire dynasties.
I think it would be pretty great if the cause could be isolated and removed.

I think it would be pretty great if the cause could be isolated and removed.