Sort:  

It might be that by picking only the strongest to survive, it caused them to have stronger mothers that lessen the chance of babies dying at childbirth. 🤔🤔

I know this is really hard and very brutal @mindakamei. But it's the same in nature, only the stronger one survives. That can be quite possible @drishyadubey. Unfortunately, not much is described about the procedure in detail. :)