IT is an often-overworked expression, but in the case of tiny McKenzie McGurk the description "miracle" baby is hardly an exaggeration -- after her amazing triumph in a fight for life that began four months ago when she was born weighing less than a bag of sugar.

But though hers is a heartwarming tale, it is also tinged with sorrow. For when she and her identical-twin sister Michigan were born 15 weeks early, only McKenzie was alive.

But, weighing just 1lb 12oz, the tiny Blackburn baby had begun a struggle for survival that, for months, was so precarious that her parents were warned not to extend their hopes beyond the next hour.

The anguish her mother and father endured is unimaginable as, one after another, McKenzie suffered life-threatening complications.

Rushed to the Special Care Baby Unit at Queen's Park Hospital as soon as she was born, the child was desperately ill. She was anaemic and had to undergo four blood transfusions. Her lungs were bleeding and she had holes in her heart. She was taken for vital surgery to Alder Hey Children's Hospital in Liverpool and it was feared she might not survive the journey, let alone the two-hour operation on her heart. And as her ordeal went on, her condition was so critical that parents Kerry and Sean had to wait more than a month before they were allowed to hold her for the first time.

Yet now their little marvel weighs 6lb and has been allowed home at last. Though still in need of regular check-ups, McKenzie is doing fine.

That wonderful conclusion to a long and desperate struggle is a mark of the tiny baby's own tenacity.

But is it not also a tremendous tribute to medical science and the dedication and skill of all the people who work in our health service -- when a child so premature, so tiny and so ill, who only years ago would have had no chance of survival, comes home safe and sound? If not a miracle, it is as good as one.