The TV presenter announced her pregnancy via Twitter.
She said: "Got some exciting news to share with you all-@Midgley and I are expecting our first baby! Woo hoo! (sic)"
She later confirmed that she had pulled out of the London marathon because she would be too heavily pregnant to take part in the event on April 7, tweeting: "Wow-thank you so much for all your congratulations messages! Due in September! and no, I'm no longer running this year's London marathon!!"
Falconer's husband, who previously appeared in Cutting It and runs his own television production company, also made the announcement on Twitter. His message read: "Exciting news twitterland, @Jennifalconer and I are expecting a mini Midgley!"
Midgley later acknowledged that a baby signalled the end of his carefree lifestyle, tweeting: "3 months down - 6 months of going out left!"