http://www.newadvent.org/cathen/01046b.htm
As to the time, let the questioner remember that no acceleration of birth is licit unless it be done at a time, and in ways in which, according to the usual course of things, the life of the mother and the child be provided for".
My qualification was to baptize the child that would otherwise die in the womb. The Baptism of the child is more important than not forcing a premature delivery.