Kate Winslet has given birth to a baby boy.

The 38-year-old British actress, who has a nine-year-old son, Joe, with her ex-husband, Sam Mendes, and a daughter Mia, 13, with her ex-husband Jim Threapleton, welcomed another son into the world at an NHS hospital in Sussex, England on Saturday (07.12.13), her first child with her third husband, Ned Rocknroll.

A spokesperson for the star told the MailOnline website: ''Kate had 'Baby Boy Winslet' on Saturday, December 7 at an NHS Hospital. Mother and Baby are doing great.''

A source close to the couple also told the New York Post's Page Six that their baby boy weighed nine pounds.

The 'Labor Day' star previously revealed she had enjoyed her third pregnancy more than the previous two.

She explained: ''I've been more active and healthier. I know more about how to take care of myself now. I think that between 27 and 37 was a big learning decade. I've been lucky - a bit tired and a bit sick at the beginning, but nothing major.''

The Oscar-winner also revealed in October that she hadn't decided whether she would take an extended break from her career when the baby arrived.

Kate and Ned, who is billionaire Richard Branson's nephew, tied the knot in a secret ceremony in New York City in December 2012.

Just 12 of the couple's friends, including the actress' 'Titanic' co-star Leonardo Dicaprio - who gave the bride away - were in attendance at the wedding, which took place in a converted barn, and even their families were unaware of the nuptials.