White Hot! Pregnant Katherine Heigl Officially Debuts Baby Bump

The mom-to-be was glowing in a white ensemble at the 2016 TCA Summer Tour party on Wednesday

Katherine Heigl is a vision in white!

The expectant actress graced the 2016 TCA Summer Tour party on Wednesday, debuting her baby bump in a custom fitted white Christian Siriano dress that featured three-quarter-length sleeves and a demure cutout right above the chest.

She finished the look with shimmering earrings, a whimsically patterned clutch, nude stilettos and a classic style to her new shorter hairdo.

Heigl, 37, was at the event to promote her upcoming CBS legal drama Doubt, on which she will play lead character Sadie Ellis. She and her husband of eight years, Josh Kelley, will welcome their third child — and first son — in January.

Jon Kopaloff/FilmMagic

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The couple shared their pregnancy news with PEOPLE in June, while Heigl took to her blog to write about her experiences in having her first biological child (the couple adopted Adalaide Marie Hope, 4, and Naleigh Mi-Eun, 7½).

“We were considering adoption again, fostering, or pregnancy if possible,” she penned. “Seeing as I have never been pregnant and as my OB/GYN reminded me last year, I’m of advanced maternal age, I wasn’t sure pregnancy was even in the cards for us. Turns out it was very much in the cards!”

One person who’s extra excited to have a son? Heigl’s husband.

“He’s just surrounded by women. It’s me, the two girls, my niece Madison lives with us in Utah and she’s a 14-year-old girl, and then my mom,” Heigl shared during a panel session for Doubt.

She also touched on her pregnancy cravings, from sleep to food.

“I’m just tired and hungry — really hungry! For donuts. On sets they always have craft service and have three boxes of donuts every day. I just try to take a bite or two … or six,” she admitted. “The sugar thing has been really bad — and I’m not generally a sugar person.”

— Jen Juneau