"Who doesn't want a girl? They're the best and I know that's really what Kanye has always wanted. He wanted a little girl."
West wasn't present during the broadcast when Kim, Khloe and their mom Kris Jenner discovered whether the baby is a boy or girl at the doctor's office.
"Do you see a little peepee?" Kris reportedly asked the doctor while looking at the monitor.
"I don't see any peepees," the doctor replied.
"It definitely would take after his father so you would see it," Kim joked.
According to E! News, the doctor then told the ladies that Kim is expecting a girl, and the reality TV stars were all thrilled and full of smiles.
Determining the sex of Kim's baby was apparently "so frustrating" and required multiple doctor appointments prior to the big revealing moment which aired during last night's episode.
"[Kanye] was at all the previous [appointments] where we never could find out the sex of the baby," Khloe recently said during an appearance on NBC's Today show, Us Weekly reported. "So that was just the one he wasn't at. But we were videotaping it on our iPhones and everything... I think he had a concert."
Us had reported in February Kim and West are having a little girl.
"They're over the moon!" a source close to the couple told Us. "Kanye always wanted a girl."
Kim and West's first child together is due in July, and the couple have reportedly decided to take their baby on the road for West's tour several months after her birth.
The pair separately announced Kim's expecting in late December. West first spilled the news during his concert in Atlantic City when the reality TV star was reportedly 12 weeks pregnant, leading Kim to confirm her pregnancy only days later.