Jenna Dewan is the ''luckiest girl in the world'' to be romancing Steve Kazee.

The 'Step Up' actress is currently expecting a child with her boyfriend Steve, and has posted a glowing tribute to him on social media in honour of his 44th birthday, in which she praised his ''strength'' and his ''beautiful soul''.

She wrote: ''The world became a better place the day you were born...Your strength, gentleness, humor and caring beautiful soul touches everyone who knows you. I am the luckiest girl in the world to love you and be loved by you Happy birthday @stevekazee! (You're going to kill me for the last shot sorrrrry) (sic)''

Jenna and the Tony winner have been dating since the beauty split from her ex-husband Channing Tatum, with whom she has six-year-old daughter Everly.

And earlier this month, Jenna, 38, revealed she feels ''very empowered'' by motherhood.

She said: ''I believe that I can do and accomplish anything at any point with any amount of sleep with any amount of stressors in life. [When you have a child], you know that you love something and you can commit and dedicate yourself to something so much, that you can do anything. [It] made me feel very empowered.''

Steve, meanwhile, said he was ''nervous'' about becoming a father, but was ''in awe'' of the fact that there's ''life growing'' inside of Jenna.

He said: ''I'm nervous as can be, but I'm trying to just be calm about it and know that we've been doing this for billions of years, millions of years at least, so we're going to be OK. There's no way to even describe how excited you are at this moment, but we're beyond. We're very happy. It's an incredible experience. I'm, like, every day just in awe of the fact that there's a life growing inside of this human being that I love so much.''