Kris Jenner was ''ecstatically surprised'' when Khloe Kardashian told her she was pregnant because she didn't think she'd ever have kids.

The 62-year-old matriarch admitted she has ''struggled'' with the thought that her 33-year-old daughter may never have a child of her own, so was overjoyed when she and partner Tristan Thompson revealed they are expecting at a family barbecue.

After Khloe announced the news on the latest 'Keeping Up With the Kardashians' episode, Kris said: ''Hearing this news is the most special thing I think anyone can ever tell me. I'm ecstatically surprised.

''I always thought that maybe Khloe would be one of those women who didn't have kids and I struggled with that.

''It made me really sad because there was no one that was born to do this more than Khloe.''

Ahead of the big family reveal, Khloe's sister Kourtney told her she thought her sibling had put on ''a few pounds'', and after Khloe and Tristan had told the Kardashian clan, Kourtney joked: ''No wonder you gained a few pounds.''

Khloe had to FaceTime her half-sisters Kendall and Kylie Jenner because they couldn't attend the family gathering, and Kylie got emotional at the news.

She said: ''Stop. Are you kidding because I'm going to cry? I'm so happy for you. And Tristan.''

Before the big family announcement, Khloe had told Tristan via FaceTime but their signal wasn't strong enough for him to see the positive pregnancy test, so she had to tell him the news.

Describing the moment she told Tristan, she said: ''He was like, 'Oh my god. Are you kidding or are you serious?' ''

Khloe confirmed she was serious and then started crying, and admitted in the episode she was ''in a state of shock'' that she was expecting.

She said: ''I'm super nervous, but really excited. There's a million different emotions that are going on in my brain. I think I'm in a state of shock. I almost can't believe it, but a good shock.

''Tristan and I have always discussed that in August we would start trying having kids and I would get off birth control.''

But before Khloe informed her family of the happy news she told her assistant Alexa Okyle.

Her pal said how much Tristan had been talking about wanting kids, and Khloe replied: ''I know. We put it in the universe. It's totally a blessing. It's just really real.''