Two things: I wonder if God is as concerned about sexual matters as you appear to be.

Second, after three increasingly difficult pregnancies, the last of which was literally life-threatening, my wife was told by her doctor that another pregnancy would likely kill her. When we told my mother-in-law that I was going to get a vasectomy to ensure she didn't get pregnant again, my MIL insisted we talk to her pastor about it. This priest said that the Church taught it would be better that my wife die than I get a vasectomy. In this case, following the teaching would have caused death.