The football star, 32, who married Bundchen in February, revealed in September that the catwalk queen was expecting the couple's first child together. Details of the birth, reported by People.com, have not been disclosed.
The Victoria's Secret stunner, 29, is already stepmom to Brady's 2-year-old son, Jack, with actress Bridget Moynahan.
Brady confessed earlier this month that he was aware of the baby's gender, but that Bundchen preferred not to know.
He said, "I'm really the only one that knows at this point. It's a pretty good feeling knowing something that nobody else knows, especially her, a very intelligent woman."
Spokespersons for Bundchen and Brady had not returned requests for a comment as WENN went to press.
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