Nurse Lucy Letby, 32, of Hereford's Arran Avenue, is accused of murdering seven babies and also faces 15 charges of attempted murder.

She entered not guilty pleas to all charges as she appeared at Manchester Crown Court this morning.

The charges relate to the collapses of babies at the Countess of Chester Hospital's neonatal unit between June 2015 and June 2016

Opening the prosecution case, Nick Johnson KC said the Countess of Chester Hospital was a “busy general hospital” which included a neo-natal unit that cared for premature and sick babies.

He said: “It is a hospital like so many others in the UK but unlike many other hospitals in the UK, and unlike many other neo-natal units in the UK, within the neo-natal unit at the Countess of Chester Hospital a poisoner was at work.

READ MORE: Lucy Letby: prosecution opens in Hereford nurse murder trial

“Prior to January 2015, the statistics for the mortality of babies in the neo-natal unit at the Countess of Chester were comparable to other like units.

“However over the next 18 months or so there was a significant rise in the number of babies who were dying and in the number of serious catastrophic collapses.

“These rises were noticed by the consultants working at the Countess of Chester and they searched for a cause.

“Their concern was that babies who were dying had deteriorated unexpectedly. Not only that, when babies seriously collapsed they did not respond to appropriate and timely resuscitation.

“Some of the babies who did not die collapsed dramatically but then – equally dramatically – recovered.

“Their collapse and recovery defied the normal experience of treating doctors.”

He continued: “Babies who had not been unstable at all suddenly deteriorated. Sometimes a baby who had been sick but then been on the mend suddenly deteriorated for no apparent reason.

“Having searched for a cause, which they were unable to find, the consultants noticed that the inexplicable collapses and deaths did have one common denominator. The presence of one of the neo-natal nurses and that nurse was Lucy Letby.”

He told jurors at Manchester Crown Court that at the relevant time the number of nursing staff at the Countess of Chester’s neo-natal unit was between 25 and 30 nurses, along with about 15 nursery nurses.

Many of the events in this case occurred on the night shifts, Mr Johnson said.

“When upon Lucy Letby was moved on to day shifts, the collapses and deaths moved to the day shifts.”

Mr Johnson said as medics could not account for the collapses and deaths, police were called in and conducted a “pain-staking review”.

He said: “That review suggests that in the period between mid-2015 and the middle of 2016 somebody in the neo-natal unit poisoned two children with insulin.

“The prosecution say that the only reasonable conclusion to be drawn from the evidence you will hear is that somebody poisoned these babies deliberately with insulin. This was no accident.”

The collapses and deaths of all the 17 children concerned were not “naturally-occurring tragedies,” Mr Johnson said.

“They were all the work, we say, of the woman in the dock, who we say was the constant malevolent presence when things took a turn for the worse for these 17 children.”

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Mr Johnson said the two children poisoned with insulin, who cannot be identified, were two baby boys, both born twins; the first born in summer 2015 and the other born in spring 2016.

Both were poisoned a couple of days after they were born.

“Lucy Letby was on duty when both were poisoned and we allege she was the poisoner,” Mr Johnson said.

“There’s a very restricted number of people who could have been the poisoner, because entry to a neo-natal unit is closely restricted.”

The trial was adjourned until Monday afternoon, when the prosecution opening will continue.

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