It is every parent’s worst nightmare.

Outliving your child is something no mum or dad ever wants to experience.

But a distraught Johnstone couple are having to face that harrowing reality.

Mary and Richard Donnelly lost their six-month-old baby Aiden without warning as he died in his sleep from Sudden Infant Death Syndrome (SIDS) – also known as ‘cot death’.

No parent can prepare for such a tragedy.

Aiden, who was twin to brother Kieran, was a healthy and happy baby and no-one would have been able to tell he would be so cruelly taken from his loving family without warning.

Mary told The Gazette: “He was just so happy and bubbly and had a good chuckle about him.

“I woke up in the morning and Kieran had woken up. Aiden was still asleep but he loved his sleep. I brought Kieran into my room and gave him his bottle, then I went to get Aiden and he was just cold and lifeless.

“I grabbed him and ran down the stairs to Richard and he grabbed him off me and just started doing CPR on the couch.

“The ambulance showed up and we were rushed to hospital. Richard stayed in the room and everyone was around Aiden, trying to revive him.

“I was just screaming. You never think something like this is going to happen to you.”

Aiden was pronounced dead at the Queen Elizabeth Hospital, in Glasgow, at 9.39am on January 27.

A twin herself, 37-year-old Mary had already had nine children before Aiden and Kieran arrived.

She had also suffered four miscarriages before finally being told the pair of boys she had been longing for were on the way.

For most parents, it is impossible to imagine the heartache of losing a twin – and Mary admits she is still trying to come to terms with her loss.

She added: “After I’d had nine kids, I never thought I would have twins.

“I’d had four miscarriages as well so, when I found out I was pregnant, I thought it was going to be another miscarriage.

“Then they told me I was expecting twins and I just started crying with happiness.

“To then lose one of them is absolutely devastating.

“I just feel angry that there’s no explanation for it. Aiden was a healthy, happy wee boy and there was never anything wrong with him.

“It’s definitely harder not being able to have a reason for it.

“I’ve got no choice but to keep going, though, because I’ve got other kids.

“There are days when I would just rather cry all day but I can’t.”