"sex now seems to have become a leisure pursuit and pregnancy a bit of an inconvenience"

That, surely, happened in the 60s when the pill was invented, didn't it?

Alas I see all this as part of systematic demonisation of sex by the RC church with a view to establishing leverage by guilt. If you feel guilty enough, your church can manipulate you into doing (or giving) almost anything - rather like the selling of indulgences.

Other churches are just as bad - but go for different attack points.