A Rainham woman has admitted shaking a baby so violently she left him with brain damage, jurors were told yesterday.

The 26-year-old, who cannot be named for legal reasons, pleaded guilty to causing grievous bodily harm without intent and child cruelty.

She also admitted causing or allowing a child to suffer serious physical harm – four weeks into her trial at Snaresbrook Crown Court.

She will be sentenced at a later date.

A 31-year-old man, also from Rainham, is accused of failing to help the infant after the woman shook him.

Giving evidence yesterday, he said both he and the woman noticed the child was fighting for breath but did not call an ambulance for almost 12 hours.

When the baby was admitted to Queen’s Hospital in Romford, at 10pm on September 16, 2012, doctors said he was “grunting” as he tried to fill his lungs with air.

The man said: “I thought there might be something wrong with him, but I didn’t think there was something really wrong with him to call the ambulance straight away – I didn’t think about it.”

Two years after the assault the little boy is still unable to sit up unaided, can only see light and dark and is likely to have life-long neurological and mobility problems.

The man denies cruelty to a person under 16 and causing or allowing a child to suffer physical harm.

The trial continues.