The Kardashian-Jenner clan might be ever-growing but Kendall Jenner is the only child-free sibling left, and she’s explained exactly why that is.

Matriarch and self-proclaimed ‘momager’ Kris Jenner has her thirteenth grandchild on the way from five of her six kids – Kourtney, Khloe, Kim, and Rob Kardashian and Kylie Jenner.

Kourtney Kardashian has Mason, Penelope, and Reign Disick as well as a new baby on the way with husband Travis Barker, while Kim Kardashian has North, Saint, Psalm, and Chicago with ex-husband Kanye West.

Khloe Kardashian has True and Tatum with Tristan Thompson, Rob Kardashian has daughter Dream with his ex Blac Chyna, while Kylie Jenner has Stormi and Aire with Travis Scott.

Kendall remains the only sibling yet to have children and she has revealed the heartbreaking reason that is.

During the season four premiere of The Kardashians, the model opened up to Scott about her battles with anxiety and how it is the thing holding her back from starting a family.

The 27-year-old explained to him: “Yeah, I’ve been really bad lately. It’s one of the reasons why I’m actually scared to have children.”

The model previously revealed in a Vogue interview last year that she had “struggled” with anxiety for years, experiencing “good and bad days” with it.

Despite battling anxiety, Kendall – who is rumored to be dating Bad Bunny – described herself as a “relationship girl”, but revealed on the show that she doesn’t put pressure on finding a partner.

Kendall admitted that her battle with anxiety put her off starting a family too early. Credit: Marc Piasecki/WireImage

“I’m the worst single person ever, because I’m not going out. I’m not exploring anything. I just sit at home,” she admitted. “But whatever. I don’t chase – I attract.

“I’m also really good at being independent. It’s not something I’m looking for, either. I think I just find myself in relationships.”

Kendall also previously joked that seeing Kylie juggling two young kids put her off rushing into having any of her own, saying on the show last year: “This is definitely a massive birth control moment for me… It’s a lot.”

She hasn’t ruled out starting a family in future, however, telling WSJ Magazine in June: “I’m excited for that time in my life. I just know it’s not right now.”

Kendall admitted seeing her sister Kylie with two kids cemented her decision to wait. Credit: Kevin Mazur/VF23/WireImage for Vanity Fair

Kendall added that when the time comes she also plans to move away from Los Angeles to ensure privacy for her children growing up: “I try to find the balance of keeping things private and keeping things sacred. Also not letting the unfortunate frustration and stress of everyone trying to get in on it stop me from enjoying my side.”

And as for her current rumored romance with singer Bad Bunny, she remained tight-lipped, adding: “I’ll go out of my way to do things as privately as possible because I just think that that’s the healthier way of dealing with relationships anyway.”