John Travolta has called his wife's pregnancy a "miracle".

The 'Pulp Fiction' actor and wife Kelly Preston - with who he has 10-year-old daughter Ella - recently revealed they are expecting a new addition to their family, and admit the actress' pregnancy comes after years of trying to conceive again.

John said: "We tried for several years, and we didn't think it was going to happen for us.

"This is a miracle, and we feel blessed and we are so moved by the generous outpouring of support and goodwill we've received from people all over the world."

John, 56, and Kelly, 47, tragically lost their son 16-year-old Jett in January 2009 when he died after suffering a seizure during a family holiday to the Bahamas.

Family friends insist the couple do not view their baby as a "replacement" for Jett, insisting they always planned for another child.

A source said: "They can never replace him. They have always wanted to have more kids."

Initially it was believed that Kelly was carrying twins, but John has since ended this speculation with a statement on his website.

He wrote: "Some of the sites are saying that we are having twins. It's a wonderful idea, but it's untrue. We are just having one."