"We couldn't be happier," Murgatroyd, 29, captioned the snapshot. "Baby Chmerkovskiy is coming."
In the pic, Murgatroyd smiles ear to ear while standing next to Chmerkovskiy, 36, who sits in a chair as he caresses her bare stomach. Both are scantily clad — Murgatroyd in black pants and a sports bra and Chmerkovskiy in nothing but a white towel around his waist.
Though the New Zealand native hadn't publicly acknowledged her pregnancy until now, she hasn't exactly been hiding it, either. Last week, she showed off her baby bump while working out at the gym. (That photo, and the one she posted Wednesday, appear to have been taken on the same day.)
Chmerkovskiy posted his own photo — of the baby's sonogram. "Put your hand up if you're a #babyChmerkovskiy and you can't wait to drive your parents crazy!" he captioned the pic on Wednesday. "#cantwait #inlove #thatprofilethough."
The couple aren't the only ones celebrating. Murgatroyd's season 22 DWTS partner, Nyle DiMarco, congratulated them via Twitter. (The pair won the Mirrorball Trophy in May.) "Wishing you a happy & healthy pregnancy!!" the model, 27, wrote Wednesday. "Congrats again & you both will be  PARENTS."
Us Weekly confirmed in May that Murgatroyd and Chmerkovskiy were expecting their first child together. The couple got engaged December 2015 after dating on and off for three years.
Back in February, Murgatroyd exclusively told Us that she and Chmerkovskiy hope to have two or three children. "[He's] somebody that I’ve always seen as being a great father and a great husband," she said at the time. "I've always said he has the most incredible generosity. He wants to take care of everybody that he knows. He has an incredible sense of humor when you get to see it. I think that his bad-boy image is slowly kind of drifting away — and that harsh Maksim image. He is the biggest teddy bear you'll ever meet underneath that Ukrainian look. I just love him. Everything about him. He’s just a great man."
Can't get enough of Us? Sign up now for the Us Weekly newsletter packed with the latest celeb news, hot pics and more!