Being a good Catholic does not mean you have to breed "like rabbits", Pope Francis has said.
Instead parents should promote "responsible parenthood" to limit the number of their children.
The Pontiff was speaking to journalists on board his papal plane as he flew out from Manilla, in the Philippines, which has just approved the use of contraceptives in the country.
Speaking in favour of his predecessor, Pope Paul VI's ban on contraception which was outlined in the 1968 encyclical Humanae Vitae, he warned against a "neo-Malthusianism" (a fear of world population growth leading to a world food crisis), which he argued "seeks to control humanity".
But he added however: "Some think that – excuse the word – that in order to be good Catholics we have to be like rabbits. No".
He said each person should seek advice from his pastor how to do "responsible parenthood" and said the "licit" way of regulating birth control was by monitoring a woman's cycle to avoid intercourse when she is ovulating.
He cited the example of a woman he met in a parish in Rome several months ago who had given birth to seven children via Cesarean section and was pregnant with an eighth.
Francis asked: "Does she want to leave the seven orphans?
"This is to tempt God," he said, adding later: "That is an irresponsibility,"
Francis also condemned the threat of "ideological colonisation" onto developing countries such as the Philippines that masqueraded as "development aid".
He said a public education minister he knew had been offered money to construct new schools for the poor but the minister had to agree to use a course book with students which taught them about "gender theory".
"This is the ideological colonisation," said the Pope. "It colonises the people with an idea that changes, or wants to change, a mentality or a structure.
"It is not new. The same was done by the dictators of the last century. They came with their own doctrine – think of the Balilla (youth groups of Fascist Italy), think of the Hitler Youth. They colonised the people. How much suffering – people must not lose their liberty."
He added: "Every people has its own culture. But when imposed conditions come from the imperial colonisers, they seek to make (peoples) lose their own identity and make an homogeny."
He also confirmed his upcoming US trip in September, visiting Washington, New York and Philadelphia.