Nicole Kidman reveals she wants to have a baby this year

Nicole Kidman wants to have another child. Photo / Getty Images

She is already a mother of four -and is fast approaching her 50th birthday - but Nicole Kidman today reveals her desire to have another child.

The Hollywood A-lister has suffered several "heartbreaks" during her attempts to conceive, but says she still hopes to become pregnant again in 2017 as "children are the joy of my life".

"In everything that has happened in my life, being a mother has been the overriding thing that has changed everything and made it better," she said in an exclusive interview with The Mail on Sunday's Event magazine.

Nicole Kidman and Keith Urban arrive with daughters Faith Urban and Sunday Rose Urban. Photo / Getty Images

The actress adopted her oldest children, Isabella, now 25, and Connor, 21, when she was married to Tom Cruise. Then, "against the odds", she conceived daughter Sunday Rose naturally with her second husband, country music star Keith Urban, giving birth eight years ago. Their second child, Faith was born through a surrogate five years ago.

But she does not want to stop there. "I still have the faintest hope that something may happen to me this year," she said. "Keith and I would love to have more babies. My grandmother gave birth to my mother at 49. I would be beyond happy and just welcome it with open arms."

Ms Kidman is remarkably candid about her struggles to conceive, saying: "You go through heartbreak again and again and then you start to tell yourself it might never happen. I honestly never believed I would actually give birth to a child, then at 41 I became a mother.

"After so many years of trying, it was so against the odds. We went through a surrogacy with my second daughter because we wanted another child so much that it hurt. I felt my chances of conceiving again were slimmer and slimmer. And then we got Faith."

Actress Nicole Kidman and actor Tom Cruise in 1991. Photo / Getty Images

Kidman said she was "at peace" with Cruise - whose growing interest in Scientology was said to be a factor in their divorce - and said of the children they adopted: "They are still a part of my life and my heart but they are adults now and they have their own lives and I'm incredibly protective about their privacy.

"It's true it gets harder and harder to get together as kids get older, but your children are always your children. When you are a mother, you are a mother for life."

Her marriage to Urban had its challenges. Four months after their 2006 wedding, he sought treatment for alcohol and drug addiction.

But Ms Kidman, who turns 50 in June, said ending the marriage was never an option. "That wasn't going to happen. When I met Keith, the connection between us was deep, there was a loneliness in both of us.

"It doesn't matter how famous you are - you can still feel loneliness and we saw that in each other. We got engaged after a month, and that was a leap of faith for both of us."

And she said she saw Urban's stint in rehab "as a good thing" as it showed his commitment to a new life.