The nun, originally from El Salvador, claimed she did not know that she was pregnant.
She was rushed to a hospital after experiencing severe abdominal pain.
An ultrasound scan revealed she was expecting a full-term baby, who was delivered by doctors during a natural birth Friday.
“The baby is one of God’s creatures and we have the utmost respect for human life. Pope Francis himself has recalled, that human errors aside, the dignity of the individual must be respected,” said Fabrizio Borrello, a priest.
“The nun will take care of her baby,” he added.
All the other nuns at the convent were also unaware of the pregnancy and were “shocked” at the birth, the priest said.
Doctors and health authorities have declined to comment.