A Wisconsin woman is starting the new year a little differently than she expected after she went into labor on an airplane more than two months before her baby's due date.

Allison Peery of Madison said Friday that she and her husband were on their way home from visiting his family near San Francisco on Wednesday when she felt her water break.

The plane was diverted to Salt Lake City, and a doctor on board helped her as contractions began.

Karl William Peery was born at a Utah hospital, weighing 4 pounds 7 ounces. He's doing well, though he's expected to be hospitalized for at least a month.

The 36-year-old woman says doctors aren't sure why he was born early because she had an uneventful pregnancy and was cleared to fly.