Kim Zolciak is expecting twins

Kim Zolciak arrives at the NBCUniversal summer press day held at The Langham Huntington Hotel and Spa on April 18, 2012, in Pasadena, Calif.
Frederick M. Brown/Getty Images

Kim Zolciak is already a mother of four, and that number is about to expand by two.

The "Don't Be Tardy" star has revealed she and husband Kroy Biermann are expecting twins.

"I couldn't be more excited," Zolciak, 35, told E! News. "I was completely shocked. I had no idea. It was a natural conception, but twins do run in the family, so I guess I shouldn't have been surprised."

Zolciak, who also stars on Bravo's "The Real Housewives of Atlanta," is already a mom to sons Kroy Jr., 2, and Kash, 9 months, with Biermann. The Atlanta Falcons player, 27, also recently adopted his wife's two daughters, Brielle, 16, and Ariana, 12, from previous relationships.

"I can't believe I am going to be a mom to six children," she said. "It's going to be very busy, but it's a dream come true."