Former US women’s soccer star Heather O’Reilly has announced the birth of her first child, a baby boy named William.

The three-time Olympic gold medallist, 35, shared the happy announcement with a photo of the new arrival with his arm aloft in an apparent early celebration.

She wrote: "William O’Reilly Werry came into this world at 5:37 am on June 18th. 6 lbs 10 ounces. 

"Clearly a champion," said the former Arsenal player. "Our little prince William! We are spilling out with love."

O’Reilly and her husband Dave Werry, a former college lacrosse player in Canada, initially announced in December they were becoming parents for the first time.

They posted a photo of a pair of trainers captioned: "The world doesn’t know what’s coming. Baby boy joining us in June! Let’s do this."