"As Saint got bigger though, she talked more and more about a third baby. She thinks her kids have grown up too fast," a source close to the Keeping Up with the Kardashians star tells PEOPLE

By Natalie Stone
June 21, 2017 08:46 PM

Kim Kardashian West can’t wait to give her daughter and son another sibling!

“Kim and Kanye will use a surrogate to carry their third baby. They are both very excited to give their kids a sibling,” a source close to the Keeping Up with the Kardashians star tells PEOPLE. “Things are great between them. They act very happy together.”

On Tuesday, another source confirmed to PEOPLE that Kardashian West, 36, and her husband Kanye West — who are parents to 4-year-old daughter North and 18-month-old son Sainthave hired a surrogate. The Kimoji creator has long made it clear on KUWTK that she wants another child, but doctors have warned her about the health risks of carrying another baby.

“Kim was never going to let herself get pregnant again. It’s just too dangerous for her. Kanye was initially the one pushing for baby No. 3,” says the source.

During her pregnancies, she suffered from placenta accreta, a condition in which the placenta grows into the wall of the womb and prevents it from easily detaching at the time of birth.

“Kim felt two healthy kids were enough,” says the source.

But, “as Saint got bigger though, she talked more and more about a third baby,” the source says, and adds, “She thinks her kids have grown up too fast.”

“She really misses having a baby in the family,” the source explains. “They looked for a while before they found the perfect surrogate.”

Credit: Source: Kim Kardashian Instagram

The reality star previously opened up in her blog about giving birth to her first child while dealing with placenta accreta, which she said affects five percent of women giving birth.

“My doctor had to stick his entire arm in me and detach the placenta with his hand, scraping it away from my uterus with his fingernails. How disgusting and painful!!!” she wrote. “My mom was crying; she had never seen anything like this before. My delivery was fairly easy, but then going through that — it was the most painful experience of my life! They gave me a second epidural but we were racing against time, so I just had to deal.”

FROM PEN: Katherine Heigl Reveals the Emotional Way She Told Her Daughters She Was Pregnant

Still, despite her past health complications, the couple, who wed in May 2014, is hopeful that they will be parents to another baby.

“I’d just love nothing more than to expand my family and just know that I have this world at home that’s safe,” Kardashian West said on the E! reality show.

“And if for some reason I left this earth sooner than I really wanted to, then my kids would have a support system at home so that I know that they would be okay if I wasn’t here,” she added.