Yours is a very old and unanswerable cry. Why did God allow terrorists to fly airplanes into the Twin Towers? Why did God allow an ignorant father to toss his toddler off the Viaduct and then jump after her? (Father was killed; toddler survived.) Why does God send babies by the hundreds to people who toss them in dumpsters, leave them in snowbanks, drown them in Wal-Mart toilets and so on, and send my good friends a long-awaited baby who died at 9 weeks of massive pediatric cancer throughout his entire body? Why? Because.
Nevertheless we must play the cards we are dealt. Prayers for not only this child, but for the mother who put her desire for regular sex over the life of her child. God created the rules and expects us to live by them. Actions have Consequences. May God comfort this baby and allow his mother to live in torment for eternity.
Christians think God does intervene. There's a lot of irrationality in that because we can all clearly see big and small things every day that are worth intervention by God, things we ourselves would intervene in if granted the power to do so. Maybe Jessica Lunsford had to die for the greater good, but we as God could intervene and make it so she is shot in the head from behind before being buried in 3 trash bags, instead of letting her realize for probably hours that she was going to die by suffocation. We would have had her not be raped, even if she had to be buried alive. But, there was no intervention. No answered prayer. Probably because God took the phone off the hook, because that at least makes sense.