Smaller families.
A large percentage of American young men are only sons.
Many of them are only children.
In the old days when a family had three or four or five sons, one son going off to war or to the missions was less heartrending.
Even if the unthinkable happened in war you at least had other children to console you in your grief.
Likewise, if your son became a priest you had other sons who would carry on the family name.
Nowadays, parents with one son are much more likely to actively agitate against a military career or a priestly vocation because they have invested everything in one young man and they want to have grandchildren.
When Catholics obey the moral law regarding contraception we will have priests again.
And less divorce, and less abortion, and less sexual abuse, etc...
Good point. I would have liked to have had a large family, but we only have two girls. Still, I tell them that the most important decision they will have in life is choosing between the religious life and marriage. It tears me up because, on the one hand, I'd love to have grandchildren. OTOH, I'd love to see them serve the Church as religious. The Christian life is a life of sacrifice, not selfishness.