The English model and television presenter has been dating Argentinian polo player Andrea Vianini since last May.
"I'm feeling really good and very excited," Kidd told the Daily Mail. "I've just returned from six months in Uruguay with Andrea and I am back in the UK until the summer.
"The baby is due in August and I have the big scan next week to find out the sex."
The 32-year-old added: "I can't wait. Andrea is still overseas but he'll be back soon too."