Catherine attended the event, held at London's Park Lane Hilton, with some of her Coronation Street co-stars and looked blooming lovely as she posed for pictures.
The actress, who plays Eva Price in the ITV1 soap, showed off her growing tummy in a figure-hugging red dress with gold embellishments on the shoulders.
Catherine, who is expecting her first baby with her fiancé Tom Pitfield, wore her hair in Hollywood curls and glammed her look up further with red lipstick, metallic gold heels and her sparking engagement ring.
On 25 August, Catherine announced her pregnancy to fans on Twitter, saying she and Tom are "thrilled".
"Delighted to tell you all that @TP_PTfitness and I are expecting a bambino! Beyond thrilled :-)," she gushed.
Just a week later, Catherine logged on to the social networking site again to announce their engagement. She tweeted: "I have something to tell you all… So pleased to tell you all that I'm going to be Mrs Pitfield. I said YES!! Love you [Thomas]. So happy. What a year!!"
Meanwhile, Catherine wasn't the only star sporting a baby bump on the red carpet last night. EastEnders actress Jacqueline Jossa, who is expecting her first baby with TOWIE's Dan Osborne, showed off her rounded tummy in a midnight blue gown.
Celebrities who have announced pregnancies in 2014:
Copyright: WENN Lexie Appleby/Future Image/Bridow/Instagram