"They call it a geriatric pregnancy," the actress told Ellen DeGeneres in a new episode airing on Tuesday. "I was, you know, on my way… this is probably TMI (too much information), but I was really kinda premenopausal so to have this happen was a huge (shock).
Halle and her husband Olivier Martinez welcomed their son Maceo in October. She was already a mum to Nahla from her previous relationship with Gabriel Aubry — and she believes her six-year-old daughter played a big part in her "miracle" pregnancy.
"I mean, I didn't think it was possible to have another baby and I thought for sure I had a need to never get married again. So I've learned never to say never," Halle confessed.
"Nahla prayed and prayed for like a year and a half for a baby and a bunk bed, and she got both of those things."
When her host responded, "It's a miracle", Halle added, "Only her prayers could have done this. I didn't think it was possible at my age, honestly."
Halle recently shared a very sweet story about her daughter, while promoting her new sci-fi TV series, Extant.
Halle Berry revealed that her daughter Nahla prayed for a year and a half for a baby
In the show, Halle plays astronaut Molly Woods, who returns to earth after a year-long solo mission that leaves her mysteriously pregnant. Waiting for her at home is her scientist husband John (Goran Visnjic) and Ethan, their ten-year-old robot child.
When asked at a recent press event what she thinks makes us human, Halle said of her character's attempts to love the robot-child built by her husband, "I struggle with if a robot would evoke the same kind of feeling from me. Would I really be able to love a machine?
"My daughter just had a nightmare and in the middle of the night she came into my bed on Mother's Day night — this is what I don't think a robot would do.
"And she's saying, 'Mummy, no! Mummy, no!' And I tap her and say, 'What is it? I think you're having a nightmare.'
"She never opens her eyes and she said, 'Mummy, there's two cupcakes! A purple one and a pink one. And you're eating the pink one. And you know I want it! Mummy, no!'
"I'm not so sure a robot would of that. And that's one of the gems, one of the jewels, of what motherhood is all about."