A distraught mother who has blamed herself for her baby's sudden death has slept peacefully for the first time in 16 years.

Theresa Heathcott lost her precious baby Michaela to cot death when she was just 14 weeks old.

The 41-year-old blamed herself for her beloved daughter's death in 1990 which had always been a mystery to her.

Now a new breakthrough in research into the hidden reason for cot deaths has given Theresa peace at last and she has slept soundly for the first time since losing her daughter.

She said: "When Michaela died I was devastated. There was no reason for her dying, so I thought I must have done something wrong.

"I blamed myself all the time up until I read this study.

"I have slept peacefully for the first time in 16 years."

Scientists have found some babies have a defect in their brain which means they struggle to kick-start their lungs once their breathing stops.

The Bristol University study discovered there could also be a genetic link to cot deaths, which is the most common cause of death in babies under a year old.

Researchers found the brain cells used to restart breathing through gasping, and in turn the heart, depend on a protein which can be blocked from getting through due to a genetic defect.

Tiny Michaela was born four weeks premature at the University Hospital of North Tees on October 8, 1989 and weighed just over 2lbs.

She was almost immediately found to suffer from sleep apnoea - a condition which causes breathing to pause or stop temporarily.

She spent one month in the Special Care Baby Unit at the hospital before she was allowed home with an alarm for her sleep condition.

The alarm would sound when she stopped breathing during the night.

The Billingham mum would tap her bottom to nudge her into breathing again.

Theresa said: "She was like a little doll. It was frightening taking her home as she stopped breathing several times."

The mum continued to have concerns about Michaela's condition and just the day before her daughter's death, a GP told her she was being over anxious about her breathing.

But at 6.50am on January 14 when Theresa went in to her help her little girl she was already lifeless.

Theresa said; "I panicked. It was absolutely dreadful. I grabbed her out of her cot and ran to a neighbour's.

"I was just kicking their door in sheer panic.

"My friend's husband tried to bring her back to life but she had died."

A post mortem revealed the cause of death was sudden infant death syndrome or cot death.

Theresa's grief has consumed her since her daughter's death. She has cut herself to try to take away the pain and attempted to end her life with overdoses, the last on the anniversary of Michaela's death this year.

Her daughters Samantha, 24, and Kimberleigh, 19, have helped her through the devastation of losing Michaela.

But the study has enabled her to finally move on as she now knows nothing could have changed Michaela's fate.

"I feel like I have had some closure now - like the end of the chapter.

"I hope it means the same for other mums like me."