Kathy Hilton says she is ‘heartbroken’ that her daughter Paris Hilton has struggled to fulfil her dream of becoming a mum.

The 63-year-old Real Housewives of Beverly Hills star said she has urged her daughter to ‘relax’ as many people find it difficult to conceive.

41-year-old Paris, who married her husband Carter Reum last year, has been very open with her fans about her journey to have a baby via IVF and has previously said she wants to have two or three children with Carter.

“It breaks my heart because I know she is trying and trying and I always say, ‘Just relax,’

“So many people, they struggle and it doesn’t just happen like that,” Kathy said in an interview with E! News.

Paris has said having children is one of her “top priorities” and has already had eggs extracted for IVF.

“I would want twins first – or I don’t know, it’s hard to say,” she told E! News’ Daily Pop.

Paris added: “Like I always wish I had an older brother, ’cause I feel like if I did they would protect me and things like that…in school. So maybe a boy first.”

Paris and Carter said ‘I do’ last November during a lavish ceremony at her late grandfather’s Bel-Air estate.

She shared a sweet message to Instagram on Friday to celebrate their one year anniversary.

“This past year with you as husband and wife has been a magical whirlwind. No matter how far we travel and no matter where in the world we are, as long as we are together, I’m at home with you,” she wrote.

“I deeply cherish all of our adventures and memories, and look forward to a lifetime more by your side.

“Thank you for all of the love, happiness, and endless laughter. You are my rock and I’m so thankful to call you mine. Carter, as my partner in life, number one hype man, and best friend, I love you so incredibly much.

“Cheers to being your wifey for lifey, and to our one year anniversary together. My 11:11 wishes finally came true with you.”