Caitlyn Jenner says battling with her gender identity made her a "bad parent".
The 70-year-old reality star was born a male and was known as Bruce Jenner before her transition, and has said she originally planned to transition before she turned 40, and used to "cross-dress and go out" in secret long before she finally opened up about her struggle in 2015.
But Caitlyn also admits her battle with her "own issues" meant she "wasn't there" for her young children - who at the time were Burt, now 41, Cassandra, now 40, Brandon, now 39, and Brody, now 37 - when they needed her.
She explained: "For about four and a half years, I just tried my best to deal with it. Honestly, I thought I would transition before I'm 40.
"I would cross-dress and go out, but I never ever talked to anybody. I never talked to anybody, never did anything, never went anywhere, just drove around, you know? I got pretty good at it, so I never got caught.
"Those years, I was not a good parent. I had four kids. I was too busy struggling with my own issues and my own self. I very much regret that, that I wasn't there more for my young kids."
Caitlyn eventually decided to take a break from her transition plan when she met Kris Jenner, whom she was married to from 1991 to 2015, and with whom she has daughters Kendall, 24, and Kylie, 23.
And the 'I Am Cait' star says her eventual transition in 2015 was not the main reason for the end of her marriage to Kris, as the pair had "bigger issues" between them.
She confessed during an appearance on Rob Lowe's 'Literally!' podcast: "After 23 years, Kris and I went our separate directions. My identity ... it was not a big part of us separating. There was so many other bigger issues out there.
"[Although the] frustration with myself [caused me to be] a little bit shorter with her near the end."