If God is not sovereign over the unborn, the most elemental form of human life, then he is not sovereign over this life with its much greater complexity and our prayers are useless, and, we certainly can’t expect a life hereafter which would be even more complex.
Was God not sovereign over the multitude of ‘born’ babies in the mass slaughter in Judea during the attempt to exterminate the recently born King? Or could you say that His birth prompted the slaughter?
Do not, as a speck of dust, presume to judge God in his eternal plan. Murder is horrendous, but is not the ultimate tragedy - not by a long-shot.