Antonia Kidman and husband Craig Marran have welcomed another baby boy into the world.

Alexander Norman Kidman Marran was born in the early hours of Monday morning in Sydney, three weeks earlier than planned, weighing in at a healthy 3kg.

Kidman said in a statement this week that the baby’s arrival “caught us by surprise”.

“Alexander’s brothers and sisters are all excited and we are looking forward to spending a wonderful family Christmas together,” she said.

“We want to thank everyone for their kind wishes.”

Though it’s the sixth child for Kidman, Alexander is the couple’s second child together after 22-month-old Nicholas. Kidman has four other children — five-year-old Sybella, James, 9, Hamish 11, and 13-year-old Lucia — with her first husband, Angus Hawley.

The happy couple have reportedly signed an exclusive photo/interview deal with Who magazine. Kidman, 42, met banker Marran, 44, three years ago and they were married in April 2010. They are currently based in Singapore.