Banning Abortion Without Exception

Today Nicaragua's legislature voted to ban all abortions, even when the mother's life is in danger.  Is this justified -- much less mandated -- under the Church's teaching?  My understanding is that an intentional abortion is never morally permissible, but a procedure intended to save the mother's life is permissible even if it is certain to result in the unborn child's death.  Unless I'm missing something, I assume that such procedures would be prohibited under a total ban (unlike South Dakota's law, which contains an exception for saving the mother's life).  What's the argument in favor of a total ban and why is the Church in Nicaragua reportedly calling for one?

Rob