Kim Kardashian's mother reveals she suffered a miscarriage before the birth of her 20-year-old daughter Kendall Jenner and it was Brown Simpson who convinced her to start jogging in a bid to take her mind off of the tragedy.

"Nicole was an amazing friend," she tells People magazine. "There were some really great precious moments we shared, (ones) that you have when you spend your life with someone."

"Before I got pregnant with Kendall, I had a miscarriage at three months," she continues. "Nicole really got me through that. I had never run before and Nicole would encourage me. She got me running - and she told, me, 'I promise you'll get pregnant (again)'.

"In the middle of that, she said, 'I'm going to give you all of my maternity clothes'. Allen Schwartz made Nicole this entire wardrobe of maternity dresses. She had them in every colour. And she gave them all to me."

Jenner became pregnant with Kendall after Simpson was murdered in 1994 and her former football star ex-husband O.j. Simpson was put on trial. During the court case, the U.S. reality star would wear the maternity clothes Simpson gave her.

"That kind of gave me this crazy strength," she says. "One day I'll hopefully be able to say to God, 'Why did you take her so young'. But (until then), it gives me great comfort to say my prayers and talk to her. I loved my friend really hard. And (her death) was a loss for so many."

Kris, who also named her daughter Kendall Nicole to honour her late friend, will be forced to relive the heartache of Nicole's death as she watches upcoming TV drama American Crime Story: The People v. O.j. Simpson, in which the reality TV matriarch will be portrayed by Selma Blair and her late ex-husband Robert Kardashian, who served as O.J.'s lawyer throughout the murder trial, will be played by former Friends star David Schwimmer.