There are now 35 STD's. The Church has been accused of being obsessed with sex. However, she has an obligation to warn people of the dangers of the abuse of sex. When you mess up in this area, you mess up big. The two are meant to go together.
Artificial contraception sets limits on self-giving.
In so doing, it changes the nature of the act by creating distance between the partners. When it was being developed they tested both male and female versions. Both worked, but the treatment caused secondary effects in men. The researchers then discontinued work on a men's pill, and moved the program to Puerto Rico where they resumed research on women. Three of their subjects died.