Gwyneth Paltrow was admitted to hospital because she is expecting her third child, according to U.S reports.

The Shakespeare In Love star spent Monday night at New York’s Mount Sinai Hospital, where she underwent treatment for an unknown ailment. But the New York Daily News claims Paltrow was taken to the hospital by her husband, Coldplay’s Chris Martin, because she is pregnant.

A source tells the publication they saw the couple in the maternity wing of the hospital, adding, "They looked very serious. She looked upset. They went right past everyone and into the elevator. It seemed like they were expected."

However, Paltrow’s spokesman Stephen Huvane says speculation about a troubled pregnancy is "guesswork at best."

He adds, "This is a private matter not for public consumption." The couple already has two children, Apple, three, and one-year-old Moses.