Speaking on the plane home from a trip to the Philippines the Pontiff said there would be no change on the doctrine surrounding birth control but added Catholics could avoid getting pregnant.
He was responding to a question from a reporter who raised the issue that some Filipino families were having children they could not afford.
But now Francis has said: "I have heard it said that families with many children and the birth of many children are among the causes of poverty. I think that is a simplistic opinion."
The Pope added that poverty was caused by the economic system and its "throw-away culture."
He has also clarified that he believes large families are a gift from God.