Tiger Woods had double cause to celebrate on Saturday when he announced on his 31st birthday that his wife, Elin, will give birth to their first child this year.

"We are expecting our first child this summer," the American world number one said on his official website.

"Obviously, we couldn't be happier and our families are thrilled. I have always wanted to be a dad. I just wish my father could be around to share the experience."

Woods's father, Earl, died early last May after a long battle with cancer.

The son took a nine-week break from golf to deal with his father's illness and death before ending the 2006 PGA Tour with eight victories, including two majors.

Despite his remarkable golfing form in a season he rates as his best ever, Woods described the year overall as one of loss.

"Certainly (this was) the most difficult season I've ever had," he said before winning the Target World Challenge in California last month, his final tournament of 2006.

"You don't ever want to lose a parent, your father, your mentor, your best friend.

"When that day happens . . . you think you can handle it and all of a sudden it happens and you find out it affects you much deeper than you thought previously."

Woods, who married Elin Nordegren from Sweden in October 2004, has frequently spoken about becoming a father.

He has decided to skip this week's season-opening Mercedes Championship in Hawaii to spend more time with his family.

The world's number-one-ranked player and 12-times major winner will launch his 2007 PGA Tour campaign with his title defence at the Buick Invitational outside San Diego from January 25th to 28th.