A female pilot whale that was euthanized after stranding itself on Wells Beach late last week was determined to be pregnant and very thin, according to an autopsy performed Monday by marine officials.

The reason for the stranding, however, is still inconclusive at this time, said Lynda Doughty, stranding coordinator with state Department of Marine Resources. More results are necessary to determine an official cause, she said.

Beachgoers reported the whale swimming close to the shoreline about 9:30 a.m. Friday. It beached itself around noon, and passers-by pushed it back into the water while they waited for marine officials to arrive.

The whale remained close to the shore and beached itself again around 9:30 p.m. Saturday. The whale was in "rough condition" and was euthanized.