Tyra Banks welcomes her first child via a surrogate mother

Tyra Banks has announced the surprise birth of her first son, after ongoing struggles with her fertility lead her to use a surrogate mother.

The 42-year-old supermodel from California, USA, announced the birth of her first child to her 3.7 million Instagram followers on Wednesday evening.

The America's Next Top Model presenter and her Norwegian photographer boyfriend Erik Asla have named their son York Banks Asla.

Tyra isn't the only celeb to share some exciting baby news today!

Sharing the news on her Instagram, Tyra said; '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.'

In the past Tyra has been open about her struggle to conceive and undergoing IVF treatment in a bid to have a child; '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.'

Speaking to People magazine, Tyra said; 'We are so excited for our new baby boy bundle of joy. The journey to now has not been an easy process, as I've shared before. But there was a beautiful bright light at the end of the tunnel for me and his father, Erik.'

Tyra first made the decision to tell the world about her problems getting pregnant after fellow model Chrissy Teigen – wife of singer John Legend – detailed the obstacles they had faced.

During a TV appearance in September 2015, the business mogul said; 'I want to co-sign what Chrissy is saying and say – you have no idea what people are going through – so when you ask Chrissy [why you don't have kids] or me or anybody that, it is none of your frigging business, okay?'

Clearly in love with her new bundle of joy, the new mum gushed; 'As I gaze into the beautiful eyes of my son, I think about all the people who struggle with fertility or carrying a child and continue to pray for them every day. My hopes and dreams are filled with well wishes that they get to feel what my little treasure, York Banks Asla, feels like in my arms.'

Congratulations to the new parents!