Gov. Sarah Palin and her husband are expecting their fifth child in May, she announced Wednesday.

Palin, 44, who just three months ago was modeling for the fashion magazine Vogue, doesn't look seven months pregnant.

"I will be delivering an addition to the first family," Palin told a stunned group of reporters.

The Republican governor, now in her second year as Alaska's chief executive, said she does not believe the pregnancy will affect her ability to run the state. Palin has been mentioned as a potential running mate on the Republican presidential ticket.

She said her work as Wasilla mayor had only a brief interruption when she had her youngest daughter, Piper, six years ago.

"I had Piper on a Monday and I was back to work on a Tuesday," Palin said. "I even brought her to work with me."

Todd Palin, a worker in the North Slope oil fields, is on leave from his job with oil giant BP PLC.

The other Palin children are Track, 18; Bristol 17; Willow 13; and Piper, 6.

Track enlisted in the Army last year and has been assigned to Fort Wainwright in Fairbanks.

Former Massachusetts Gov. Jane Swift was the nation's first governor to give birth while in office. She had twin girls May 15, 2001.