The couples gathered for this Mass with Pope Francis knew a thing or two about marriage, since they were celebrating their 25th, 50th or 60th wedding anniversaries.

Still, the pope delivered a blunt homily on a painful family issue. The bottom line: Many Catholics do not want children.

"There are things that Jesus doesn't like," said Francis, in a 2014 service at the Vatican guesthouse he calls home. For example, there are parents who simply "want to be without fruitfulness."

Today's "culture of well-being," he said, has "convinced us that it's better to not have children! It's better. That way you can see the world, be on vacation. You can have a fancy home in the country. You'll be carefree." Apparently, many Catholics think it's easier to "have a puppy, two cats, and the love goes to the two cats and the puppy. … Have you seen this?"

Yes, Catholic leaders can see that reality in their pews and they know falling birth rates are linked to many sobering trends, from parochial-school closings to once-thriving parishes needing sell their sanctuaries.

Then there is the annual survey from Georgetown University's Center for Applied Research in the Apostolate (CARA) reporting the number of men poised to be ordained as Catholic priests in the United States.

The class of 2018 is expected to be 430, and 25 percent of those men were foreign-born.

It's an often quoted fact: The number of men ordained each year is about a third of what's needed to replace priests who are retiring, dying or simply leaving. Two decades ago it was common to see between 800 and 900 ordinations a year.

Birth rates are the "overlooked factor in all of this," said sociologist Anne Hendershott, who leads the Veritas Center for Ethics in Public Life at Franciscan University of Steubenville, Ohio. "It's kind of difficult to talk about this, because Catholic families used to be huge, which meant parents were willing to give up a son who wanted to enter the priesthood. Things have changed, obviously."

Catholic families in America are shrinking.