The parents of a tragic baby who were convicted over extensive injuries he was found to have suffered after he died of pneumonia and sepsis have each been jailed for eight years.

Marina Smyth, 21, and Michael Osborne, 22, had denied causing or allowing physical harm to a child at their Tonbridge home, but were found guilty.

Passing sentence, Judge Adele Williams called it “cruelty of a high degree”.

Maidstone Crown Court heard a post mortem examination revealed 19-day-old Bailey Smyth-Osborne had a fracture to his leg and bruising to his head and penis.

Experts said the head injuries were consistent with “more than one blunt impact” and the break to his left tibia with a twisting or yanking motion.

Smyth looked tearful as the judge told them: “Bailey deserved be loved, to be cared for and to be protected by you as parents, instead of which he was caused those injuries and the suffering which accompanied them.”

Judge Williams said she could not be sure who actually caused the harm but the evidence pointed to it being Osborne.

She added they had to both bear equal responsibility and blame for causing or allowing the injuries to occur.

The judge said Bailey was found to have “a catalogue of horrifying injuries” in the post mortem examination.

“You have, in my judgement, been convicted on compelling evidence of causing or allowing significant harm to your baby,” she said.

Expert evidence showed the harm was caused by inflicting significant force – the fracture likely to have been by pulling, yanking or twisting the leg, either picking him up by his feet or swinging him by his feet.

The fracture was so severe it went through the whole bone. The head injuries were likely to have been caused by blunt force trauma and the penis injury by pinching.

“Those injuries would in my judgement have caused great pain and suffering and continuing discomfort,” said Judge Williams. “He would have been screaming and crying.

“These injuries, I remind myself, did not contribute to his death.”

The judge said she was sure on the evidence there was more than one “event” when the harm was caused, and could have been as many as four incidents.

“I am sure you both lied about what happened,” she continued. “You lied right from the start, because you lied about the circumstances in which you came to find the baby dead.

“You both said you did not wake up until 10am and found him dead, but that can’t be true. Rigor mortis had already set in when paramedics arrived at 10.45am.

“The circumstances in which each of you described finding him are simply unbelievable. I am sure you both delayed calling for an ambulance because you feared the authorities would discover the injuries on Bailey’s body.

“Each of you then believed you had caused Bailey’s death. During the trial, each of you has sought to blame the other. Neither of you has shown any remorse.

“I am sure both of you sought to deceive the authorities and ultimately this court by devising explanations about how some of the injuries were caused.

“You, Marina Smyth, decided to abandon Michael Osborne and recorded him on your mobile phone to make admissions which could not possibly account for the injuries, and were not the whole truth or any part of it.”

The judge added: “I am sure there are multiple incidents of serious cruelty and some degree of gratuitous degradation by injuring his penis. The physical harm was substantial.

“There is also deliberate concealment and covering up. The victim was particularly vulnerable at three weeks old. I regard this case at the top of the range.”

The maximum sentence for the offence is 10 years imprisonment.

Richard Barraclough, QC for Smyth, submitted his client should be sentenced on the basis she was a devoted young mother who did not inflict any of the injuries but “should have been aware of the risk, rather than was aware of the risk”.

He further submitted that Osborne inflicted the injuries in a momentary loss of control. He agreed there must have been an element of concealment.

Smyth, he said, lost her child in tragic circumstances unrelated to the offence.

Mr Barraclough said a distinction should be drawn between the perpetrator and the non-perpetrator, but Judge Williams said she disagreed as she considered them to be equally culpable.

Danny Moore, for Osborne, said the evidence suggested a level of immaturity on the young father’s part. He invited the judge to conclude the injuries were inflicted over a short period of about three days.

Bailey, he said, would not have been well and it would have been difficult to feed and settle him. The mistreatment was likely to have been spontaneous.

“He has lost his son,” added Mr Moore. “It is probably unlikely he will have any more children.”

Prosecutor Jennifer Knight had told the jury it was the Crown’s case that one of the parents was responsible for the injuries and the other, although not the actual perpetrator, allowed them to occur by failing to take reasonable steps to protect him a risk of injury which should have been foreseen.

Bailey was born on November 16 2016 at Pembury Hospital and Smyth was discharged home to their flat in Walters Farm Road the same day,

At about 1am on December 5, a neighbour at the flats heard a baby’s high pitched crying lasting 20-25 minutes.

Smyth told how she awoke at 10am and found Bailey was stiff, cold and unconscious in his Moses basket. She said she told Osborne she did not think the baby was breathing.

An ambulance was not called until 10.45am.

Paramedics found rigor mortis had already set in. Despite continued CPR, there was no response. He was taken to Pembury Hospital, where he was declared dead.

Consultant paediatrician Dr Uday Kumar examined Bailey and saw a number of injuries – a 5cm line of bruising on the right side of the head, 3cm above the ear and bruising about 1cm in diameter near the base of the penis.

Pathologist Dr Nathaniel Cary concluded after a post mortem examination that the cause of death was bronchial pneumonia and sepsis.

“There was evidence of fresh bruising to the penis, left elbow, the fingers of the left hand, the left ankle and the right heel,” said Miss Knight.

“Dr Cary considered these bruises to be consistent with mild to moderate force, blunt impact or compression.

A CT scan showed a fracture to the left tibia. Professor David Mangham described the type of fracture as being caused by “forcible traction – pulling with a twisting motion”.

He judged that the injury was caused between 24-72 hours prior to death, but most likely 24-48 hours before.

The pathologist concluded that both the bruising and fracturing indicated a level of trauma beyond rough handling and in keeping with assault in the period leading up to death.

Smyth, now of Oxford Gardens, Maidstone, said in evidence Osborne confessed to her that he believed he may have caused the fracture and “pinched his willy”.

An NSPCC spokesperson said: “The injuries inflicted on Bailey and the pain he must have suffered during his short life is hard for anyone to imagine.

“More shockingly, those injuries were carried out by the very people who should have protected him from harm.

“All parents can come under pressure at times but there are no excuses for physically abusing babies and young children."

The NSPCC offers advice and support for parents on coping with crying and other stressful situations on its website www.nspcc.org.uk

If you suspect a child is being abused report it. It could save a child’s life. Call the NSPCC Helpline on 0808 800 5000. Children can call Childline on 0800 1111.