"This is a dream come true for us," the 27-year-old Federer said. "We love children and we are looking forward to being parents for the first time. Mirka is feeling great and everything is going well."

The baby is due sometime in the summer, he said.

"We are so happy to be starting a family together," said Federer, who met Vavrinec at the 2000 Sydney Olympics.

The 13-time Grand Slam champion is in Indian Wells, California, for the Masters tournament, which started on Thursday.

Federer, who lost to Rafael Nadal in five sets in the Australian Open final, pulled out of Switzerland's Davis Cup series against the United States and withdrew from the Dubai Tennis Championships because of an injured back, but he said it is better.

"I arrived in Indian Wells earlier this week and I am eager to get back out on court," Federer said. "My back is feeling much better and I am ready to go."