Ashton Kutcher's mother didn't know she was pregnant with his twin until 2 hours before she gave birth

• Ashton Kutcher revealed his mother did not know she was pregnant with twins until two hours before she gave birth.
• Kutcher appeared with his twin, Michael, on the series premiere of "The Checkup with Dr. David Agus."

Many people aren't aware that superstar Ashton Kutcher has a twin — and neither was his mother, until two hours before she gave birth.

Kutcher revealed his mother wasn't aware she was carrying twin boys — both the future "That 70s Show" star and his fraternal twin, Michael — for much of her pregnancy on the series premiere of "The Checkup with Dr. David Agus." The show, which premiered on Paramount+ on December 5, features Agus, a famed cancer researcher who treated Steve Jobs, talking to celebrities like Kutcher about their health.

Kutcher said doctors did not identify a second heartbeat in their mother's initial and follow-up ultrasounds, explaining the "way that the world basically treated women who were pregnant was far different than today."

"Our mother didn't know she was carrying twins," Kutcher told Agus. "As they were leaving to go to the hospital our older sister said, 'Bring me one home, too.' And sure enough she was pregnant with twins and didn't realize it because in the original scan that they took they only saw one."

Michael Kutcher said their mother wasn't aware she was pregnant with twins until two hours before she gave birth.

"I was essentially behind him," Michael said. "After he was born, five minutes later I come along."

Michael appeared on the show alongside his brother to discuss their childhood and how they grew apart as Ashton's career ascended.

Michael has cerebral palsy, a neurological condition that can cause a variety of health problems like trouble with motor function, vision and hearing loss, and intellectual disability. Michael said he doesn't have too many cognitive or motor problems, but slightly slurs his words and has trouble seeing.

Michael told Agus he had initially felt jealous when his twin achieved superstar fame, and Ashton admitted to being "an asshole" when he first experienced success. The two said they've since reconciled their differences and become close again.

Michael is involved with the Cerebral Palsy Foundation as an advocate and public speaker. He has raised awareness of the condition for local and national fundraisers, and talked about his cerebral palsy with the Centers for Disease Control and Prevention and National Institutes of Health, per his website.