NORFOLK, Va. - A female sailor who reported to the USS Yellowstone's sick bay with cramps early Sunday delivered a big surprise five minutes later: a baby boy. Officials believe it's the first time in U.S. naval history a sailor has given birth aboard ship.

The woman, a 21-year-old seaman apprentice assigned to the Norfolk-based destroyer tender, delivered what officials said was a healthy, full-term, 5-pound boy early Jan. 16, said Cmdr. John Tull, spokesman for the Atlantic Fleet's Surface Force.

The ship was in port at Gaeta, Italy, one month into a six-month assignment to the Mediterranean.

The child was delivered by the ship's doctor. Mother and child were immediately transferred off the ship to an Italian medical center, and later admitted to the U.S. Naval Hospital in Naples.

The mother, whom the Navy would not identify, joined the Navy a year ago and reported to the Yellowstone in July. The ship left on its current voyage Dec. 29. Once under way, officials aboard the ship became suspicious, but the sailor denied she was pregnant, said Atlantic Fleet spokesman Cmdr. Morgan Smith.

Supervisors decided to require a pregnancy test on Jan. 13. The following day, the test came back positive. Tull said the sailor's comments to medical personnel led them to believe she was in the early stages of pregnancy, with an estimated delivery date in September.

Two days later, the woman reported to sick bay with cramps. Five minutes later, the ship's doctor delivered the child.

Under normal circumstances, said Tull, pregnant sailors can be remain aboard ship until the 20th week of pregnancy. Under no circumstances, he said, are they allowed to deploy overseas.

Despite the rule, Smith said the Navy isn't contemplating disciplinary action. The Navy is arranging to fly the woman and child back to the United States. Per regulations, she will be given six weeks' convalescent time and will not be returned to sea duty until four months after giving birth.