A male babysitter who shook a five-month-old baby so violently that she suffered catastrophic and permanent brain injuries as a result has been sentenced to 10 years.

Sophie Reed and Luke Taylor had asked 28-year-old Stephen Carl Smith, a family friend, to look after their daughter while they went out for a date on August 18, 2016, Daily Mail reports. However, at some point during the night, Smith violently shook little Baylee-Lee Taylor.

Luke and Sophie had asked their friend Smith to look after their newborn child while they went out on a date night on August 18, 2016. (Pixabay)

The assault left the infant with a series of health problems, including cerebral palsy, epilepsy causing seizures and spasms, feeding and mobility issues, delayed development, poor sleep, and the almost total loss of sight.

As a result of Smith's actions, little Baylee-Lee will never be able to attend regular school as she needs personal supervision and care at all times.

During a trial at Swansea Crown Court, Smith denied shaking the child. However, he was later found guilty of inflicting grievous bodily harm with intent to the innocent child.

Luke and Sophie had asked their friend Smith to look after their newborn child while they went out on a date night on August 18, 2016. They had plans to go sea-fishing together for a couple of hours.

Smith had known Taylor for years and had babysat for them before. On the fateful night, he agreed to look after Bayleigh-Lee provide he could be dropped home at the end of the night.

But when the couple returned to their Merlin's Bridge, Pembrokeshire residence, they found the infant "propped up on a chair" and apparently sleeping.

The couple proceeded to the kitchen thinking everything was okay, but there was a sudden "piercing cry" from the other room.

They rushed back to the living room to find the infant on the ground. They immediately picked her up, but soon realized she was "limp and lifeless."

Emergency services were called to the scene and the baby was rushed to Glangwili Hospital in Carmarthen, before being transferred to a special unit in the University Hospital of Wales in Cardiff for further medical attention.

Stephen Rees, prosecuting, said detailed examinations had determined the infant had suffered "non-accidental head trauma" which resulted in "life-changing and catastrophic" injuries to the brain.

While Bayleigh-Lee is now back at home receiving medication, physio, and intensive care, she will never be able to attend regular school as she required one-to-one care at all times.

Her devastated parents told the court how their lives had been "turned upside down" following the incident. In the first few months, social services prevented them from seeing the infant or their other two children.

While they acknowledged their child could never lead the life she could have due to Smith's actions, they said they "will always be proud of the things she achieves, and we will always be proud of the strong-hearted person she will become."

During the trial, Judge Peter Heywood said the court had heard evidence from Dr. Peter Richards, a leading consultant pediatric neurosurgeon, for the injuries the baby sustained and how they were possibly inflicted.

Bayleigh-Lee's injuries led to bleeding on the brain after the person charged with caring for her suffered a "momentary loss of control", Judge Heywood said.

While it was not known what exactly transpired that night, the judge said "something went disastrously wrong" and that force was used resulting in "catastrophic injuries."

Judge Heywood subsequently sentenced Smith to 10-year term -- half in custody and the other half on a license.

Bayleigh-Lee's parents now hope the case highlights the issue of "baby shaking."

"We have spent three-years not really being able to speak about what happened," Luke, 29, said. "We now have the result we wanted, and the result Bayleigh-Lee needed. We want people to know, to be aware, of this type of thing - it is not really talked about."

Sophie, 27, is now caring for Bayleigh-Lee full time. She described the pain she felt after being separated from her own children following the incident.

The devastated family, however, has been left not knowing exactly what happened that night as Smith continues to deny any wrongdoing.

"I don't think we will ever get an apology," she said. "I don't think he is sorry."

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