Tyra Banks has welcomed her first child

The 'America's Next Top Model' host - who has opened up about her fertility struggles in the past - took to Instagram to announce that she and partner Erik Asla have got their "miracle baby boy" York as they thanked the "angel" surrogate mother.

She wrote on the photo sharing site: "The best present we worked and prayed so hard for is finally here. He's got my fingers and big eyes and his daddy Erik's mouth and chin.

"As we thank the angel of a woman that carried our miracle baby boy for us, we pray for everyone who struggles to reach this joyous milestone. York Banks Asla, welcome to the world. (sic)"

Meanwhile, the 42-year-old supermodel previously revealed she has had to endure "traumatic" rounds of fertility treatment in the past.

She said: "When I turned 40, the one thing I was not happy about is that I did not have kids. I'm like, 'Damn, the clock is ticking!' When you're like, 'OK, I'm just going to do it,' then it's not so easy as you get older."

"I've had some not happy moments with [IVF], very traumatic moments. It's difficult as you get older. It's not something that can just happen."