Francis, who has come to be known for introducing a more simple style at the Vatican, told the mothers of the babies not to be intimidated by the grandeur of the chapel, CNN reported Sunday.
The pope offered a brief homily at the ceremony, focusing on the babies.
"Today the choir sings but the most beautiful choir is of children," he said. "Some are crying, because they are uncomfortable, or because they are hungry. If they are hungry, mothers, give them something to eat. ... They are the central figures, the protagonists."
The pope then poured water from a shell-shaped dish onto the heads of the infants.