He is 77, celibate, and occupies a role that tends to entail at least a modicum of prudishness. But Pope Francis is nonetheless emerging as an unlikely champion of public breastfeeding, encouraging mothers to tend to their babies – even in front of him and, possibly, in the Sistine Chapel.

Beneath Michelangelo's beloved ceiling on Sunday, the Argentinian pontiff told families who had brought their offspring to him for a special papal baptism that they should not stand on ceremony if the children were in need of food. "If they are hungry, mothers, feed them, without thinking twice," he said, smiling. "Because they are the most important people here."

On this occasion Francis did not use the verb "breastfeed". But he had already expressed an uncommonly down-to-earth approach to the practice in an interview with La Stampa last month. Recounting an encounter with a mother and her wailing newborn son at a general audience, he said he told her to feed him then and there. "She was modest," he recalled. "She didn't want to breastfeed in public as the pope was going past."