The transgender man gave birth to a healthy baby boy, as yet unnamed, who joins Mr Beatie’s one-year-old daughter, Susan Juliette.
Announcing his second pregnancy in an interview with Barbara Walters in the US last November, Mr Beatie said: "I feel good. I had my checkups with my hormone level, as far as the HCG. And everything is right on track."
When Susan was born last June, Mr Beatie told People magazine: “The only thing different about me is that I can’t breastfeed my baby. But a lot of mothers don’t.”
Instead, his wife Nancy breastfed Susan and it is believed she will also breastfeed the couple’s new son, who was born on Tuesday, three days premature. Sources told ABC news in the US that Mr Beatie’s new son was born naturally.
Mr Beatie, 35, was born a girl named Tracy Lagondino but had gender reassignment surgery and is now legally male, wears a beard, and is married to Nancy. Despite changing his gender, Mr Beatie had kept his female organs so he could fall pregnant one day.
After his daughter’s birth last year Mr Beatie told ABC news that he wanted to expand his family, so he did not go back onto his male hormones in order to be able to fall pregnant again. Both babies were conceived via sperm donors.
Mr Beatie went public about his first, unusual, pregnancy by posing semi-naked and holding his heavily pregnant stomach on the cover of the national American gay magazine The Advocate.
The announcement made headlines around the world as it was believed Mr Beatie was the first man to become pregnant. He said the international attention – some positive, but much of it negative – was “shocking” but he does not regret his decision to go public about his family, despite still receiving death threats.
"We are a man, woman and child. It's ironic that we are so different but yet, we're just a family, just the same as anyone else," Mr Beatie said in November.