A teenager in Alabama who was declared brain dead regained consciousness a day before his life support was due to be withdrawn.

Trenton McKinley, 13, suffered severe brain trauma in a car accident from which doctors believed he would not recover.

His parents were told his organs were a match for five children who needed transplants, and they had already signed the paperwork agreeing to donate them when their son showed signs of life.

The teenager suffered seven skull fractures in March when he fell from a car trailer which overturned and crushed his head in Mobile, Alabama.

Trenton's mother, Jennifer Reindl, said her son had undergone several rounds of surgery, suffering kidney failure and cardiac arrest.

At one point, she was told he would not recover.