The baby girl was born at 12:47am on 15 January, weighing 7lbs 6oz.
“Kanye and I are happy to announce the arrival of our healthy, beautiful baby girl,” Kardashian West wrote on her website.
“We are incredibly grateful to our surrogate who made our dreams come true with the greatest gift one could give and to our wonderful doctors and nurses for their special care.
“North and Saint are especially thrilled to welcome their baby sister.”
Last September, Kardashian West revealed that she and her husband were expecting their third child by sharing a clip from the upcoming season of ‘Keeping Up With The Kardashians’, of course.
“What happens every time I say, ‘Guess what?’” Kim was shown asking her sister Khloé over the phone.
“The person’s pregnant?” Khloé guesses before Kim announces, “We’re having a baby.”
She also shared her decision to have a child via surrogate on the reality show.
“After talking to Kanye, I think I always knew that surrogacy was an option, but I didn’t think it was that realistic of an option, and now I feel like that’s my reality,” she said in an episode of KUWTK that aired in April 2017.