Katherine Heigl announces she's pregnant with first biological child

Katherine Heigl has been married to musician Josh Kelley (left) for eight years. Photo / AP

Actress Katherine Heigl has announced she's pregnant.

According to People magazine, the actress and her husband of eight years, musician Josh Kelly, are expecting their third child, a boy, in January.

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@joshbkelley and I have some news...go to thoseheavenlydays.com and I'll tell you alllllll about it! 🍼🎉💙

A post shared by Katherine Heigl (@katherineheigl) on Jun 23, 2016 at 9:24am PDT

It will be the couple's first biological child. They are already parents to two adopted two girls, four-year-old, Adelaide, and seven-year-old, Naleigh Moon.

"The Kelley clan is thrilled to announce that we are expecting a third addition to our family," the couple told People in a statement.

"Naleigh and Adelaide could not be more excited to welcome their new sibling into the fold and Josh and I are overflowing with joy and gratitude."

"This is an incredibly exciting time for us filled with hope, anticipation, and hormones. Well, only I'm filled with hormones, but everyone in the family gets to enjoy them," Heigl joked.

"We couldn't be more excited to be able to finally share this news with our fans and are looking forward to continuing to share the journey with you all. xoxo, Katie and Josh."

Heigl, best known for her role as Izzie on Grey's Anatomy, was most recently seen in the television drama State of Affairs. The show was cancelled in 2015 after only one season.