Pope Francis says abortion can never be condoned, even when the fetus is gravely sick or malformed.
He is urging doctors and priests to support families to carry such pregnancies to term.
During an audience on Saturday with participants of a Vatican-sponsored anti-abortion conference, Francis said opposition to abortion isn't a religious issue but a human one.
"Is it licit to throw away a life to resolve a problem? Is it licit to hire a hitman to resolve a problem?", the pontiff asked.
Francis denounced decisions to abort based on prenatal testing, saying a human being is "never incompatible with life".
Francis has spoken out strongly against abortion, though he has also expressed sympathy for women who have had them and made it easier for them to be forgiven.
Australian Associated Press