US actress Hilary Duff has revealed she is expecting her second child with her husband, singer Matthew Koma. 

The 33 year-old already has a daughter Banks, 1, with Koma, and a son Luca, 8, with her ex-husband Mike Comrie.

She announced the news on Instagram with a short clip showing Koma stroking her baby bump.

Duff wrote: “We are growing!!! Mostly me ...”

She rose to fame as the lead in Disney’s ‘Lizzie McGuire’ and 'A Cinderella Story.'

Other celebrities have been congratulating the pair, with Glee star Lea Michele saying: “Yes!!!! Congratulations!!”

Actress Mandy Moore added: “Yay!! The best news!!! Love you two and can’t wait to be mamas together! Xo."

Actor Dan Amboyer wrote: “Faints. How exciting!!!!! Congratulations!!!!”