"They've got to be over the moon," about the "wonderful news," a source told PEOPLE magazine on Wednesday.
"They've always talked about wanting four kids: two boys and two girls," the insider said of Kardashian, 38, and West, 41. "That's always been the plan."
"They definitely want a boy," the source added. The rapper and reality star are already parents to daughters North, 5, and Chicago, 11 months, and son Saint, 3.
Multiple outlets confirmed Wednesday that Kardashian and West have baby number four on the way, via a gestational carrier.
In August, however, Kardashian denied that she and West were planning for another baby after rumors surfaced they might be expecting soon.
"I've been really open about it and talked about it on our show, so I don't know," the KKW Beauty founder told E! News at the time. "We start filming season 16 [of Keeping Up With the Kardashians] next week, so if I think about it more and it's gonna happen, you'll definitely see it on the show. But as of now, no."
She told ELLE in an interview last year that she was open to having four children but that would have to be her limit.
“I don’t think I could handle more than that. My time is spread really thin. And I think it’s important that in all couples, the mom gives the husband as much attention as the kids," she said at the time.
She also opened up about using a gestational carrier, making sure to note that although she sometimes uses the term surrogate. "It’s completely my and Kanye’s DNA, so technically that’s called a gestational carrier. A surrogate is when they use the husband’s sperm and the surrogate’s egg,” she said.
“I hated being pregnant,” she added, referencing her intense complications during her pregnancies with North and Saint. “But as much as I hated it, I still wished I could have done it on my own. The control is hard at the beginning. Once you let that go, it’s the best experience. I would recommend surrogacy for anybody.”0comments
A source told PEOPLE previously that West and Kardashian "would use the same surrogate if she agrees to help them again. Kim can't say enough kind words about the surrogate."
Baby number four for Kardashian and West is reportedly due in May.