Mila Kunis and Ashton Kutcher have reportedly welcomed their first child into the world.

The 'Black Swan' actress, who started dating her former 'That 70s Show' co-star in 2012 and got engaged to him earlier this year, is said to have given birth to a baby girl at Cedars-Sinai Medical Centre in Los Angeles on Tuesday night (30.09.14).

A source close to the couple told gossip website that the couple were taken straight into the delivery room after arriving at the hospital at 6am on Tuesday morning.

The insider said they arrived alone, without any family members or assistants.

It was recently revealed the 31-year-old actress was tired of waiting for her daughter to arrive and was getting desperate to go into labour.

Another insider said: ''Mila just wants the baby to come out already!

''Mila hasn't slowed down at all. She seems to have a lot of energy.''

The couple were disappointed that Mila didn't go into labour while Ashton was on a break from filming 'Two and a Half Men' last month.

A friend said at the time: ''They were hoping the baby would come this week because he's on hiatus. He is a nervous wreck.''