Prince William says he is glad that his wife is not having twins because his "mental health would be tested".
The Prince was attending the Centrepoint Awards at Kensington Palace on Thursday, when he opened up about his third child which is due in April.
“I'm getting as much sleep as I can”, said the Prince.
He also discussed the prospect of having twins.
"Twins? I think my mental health would be tested with twins." said the future King, who also told another supporter at the awards ceremony: "Two is fine, I don't know how I'm going to cope with three, I'm going to be permanently tired."
William, 35, was hosting the annual event in his role as patron of Centrepoint, a homelessness charity that Princess Diana supported.
"However, for me, tonight is one of sharply contrasting emotions. Soon Centrepoint will be 50 years old,” he said “I feel immense pride in all Centrepoint has accomplished in that time, but with it, disappointment and frustration – frustration that in one of the most prosperous countries in the world homelessness is still putting the lives and futures of our young people at risk."