Nicky Hilton gives birth to baby boy

July 5 (UPI) -- Nicky Hilton is a mom of three.

The 38-year-old fashion designer recently welcomed her third child, a son, with her husband, James Rothschild.

Hilton shared the news Tuesday on Instagram alongside a maternity photo. The picture shows Hilton and Rothschild in silhouette as Rothschild cradles Hilton's baby bump.

"We are officially a party of 5! Welcome to the world sweet boy. Mom, dad and big sisters could not be more smitten," Hilton captioned the post.

Crystal Kung Minkoff, who stars with Hilton's mom, Kathy Hilton, and aunt Kyle Richards on The Real Housewives of Beverly Hills, was among those to congratulate Hilton in the comments.

"Congratulations," Minkoff wrote alongside a heart emoji.

Hilton and Rothschild will celebrate their seven-year wedding anniversary Sunday. The couple also have two daughters, Lily-Grace Victoria, 5, and Teddy Marilyn, 4.

Hilton is the daughter of Hilton hotel heir Richard Hilton and Kathy Hilton, and the sister of television personality and businesswoman Paris Hilton.