Maria Dolores dos Santos Aveiro said he was an “unwanted baby”, but her faith in God meant she refused to go through with the termination. She first announced her dilemma in her 2014 autobiography - then claiming that doctors would not allow her to go through with the procedure.
She spoke candidly in 'Ronaldo', an upcoming documentary film showing the rise of her son to becoming a three-time Ballon d’Or winner.
PSG, MLS or the Middle East - Where could frustrated Ronaldo land next?
"He is a child that I wanted to abort," she said. "God didn’t want that to happen and I was blessed because of that and God didn’t punish me.
"Sometimes Ronaldo makes fun of me and says: 'You didn’t want me to be born. But now you see that I’m here helping all of you.' And, well, sometimes we have a laugh about that."
Cristiano Ronaldo with his agent, mother and son.
Image credit: Eurosport
The film portrays Ronaldo as a staunch family man, with particular focus on his relationship with his five-year-old son, Cristiano Jr.
Ronaldo’s own father, Dinis, died aged 53 in 2005. He was an alcoholic – something that caused immense strain on the family.
"I cried every day," said Ronaldo. "People say we have money and cars but we suffered."
He added: "He would drink nearly every day. It frustrates me that he was never able to see my successes."
'Ronaldo' is released in UK cinemas on Monday.
Ronaldo threatens to quit Man Utd this summer – Paper Round
'It is normal' - Rangnick unfazed by Ronaldo's angry reaction to being subbed