Celebrity Celebrity Family Celebrity Pregnancy Watch Pregnant Khloé Kardashian Learn the Sex of Her Baby with Tristan Thompson Khloé Kardashian is expecting her first child, a baby boy By Michele Corriston Michele Corriston Michele Corriston is the Director of Platforms Strategy of PEOPLE. She has worked at PEOPLE since 2014. People Editorial Guidelines Published on February 26, 2018 01:03PM EST Surprise!Khloé Kardashian‘s baby gender reveal “shocks” sister Kourtney Kardashian on the season finale of their reality show. In a promo for next week’s episode of Keeping Up with the Kardashians, the mom-to-be teases, “Do you want to know what I’m having?” “I’m shocked,” says Kourtney, 38, before she and Kim Kardashian West envelop their sister in a hug. Khloé, 33, officially announced her pregnancy in December 2017, and PEOPLE has already confirmed she is expecting a son with NBA star Tristan Thompson. On Sunday night’s episode, Khloé grappled with extreme pain during her first trimester, side effects of her progesterone pills. Khloe Kardashian/Instagram “I just feel sick every night,” she said. “I feel gross. I physically can barely walk.” It’s been a baby boom for the family: Kim, 37, welcomed her third child, daughter Chicago, via a surrogate in January, and sister Kylie Jenner, 20, welcomed her first child, daughter Stormi, in February. Keeping Up With the Kardashians airs Sundays on E! at 9 p.m. ET.