Catholics compared to protestants usually have far more children and we know how to make them. Protestants agreed that artificial birth control was a no-no until they changed their minds at the beginning of the 20th century...then, as usual, they made up new rules and decided that birth control was O.K.....easy to do when you've left the true church.
I've heard that...
http://www.religionnews.com/2015/01/20/breed-like-rabbits-pope-francis-breaking-new-ground-birth-control/