From The Washington Post:

"Be fruitful and multiply," God instructed Adam and Eve, and men and women have heeded those words ever since. But over the years, God's creatures have become sophisticated enough to rewrite the rules of being fruitful, and most of the new rules don't sit well with leaders of the Roman Catholic Church.

There is "great confusion among lay Catholics regarding the church's teaching on human reproductive technologies," Philadelphia's Cardinal Justin Rigali said at the meeting of U.S. bishops in Baltimore in November. "There is a need to help Catholics understand specific differences between the Catholic understanding and a secular understanding of human life."