More babies harmed in Letby’s care, files suggest
New evidence obtained by the BBC suggests that more babies under Lucy Letby’s care were harmed, including one case where a baby was poisoned with insulin.
The former nurse was convicted of murdering seven babies and attempting to murder seven others, including two by insulin poisoning, at the neonatal unit of the Countess of Chester Hospital between June 2015 and June 2016.
However, BBC One’s Panorama has reviewed documents indicating that a third baby may have been poisoned just hours after Letby began caring for the infant boy. Medical records show the baby’s blood sugar dropped sharply, and lab results revealed unusually high insulin levels.
Panorama also uncovered that nearly one-third of potentially life-threatening incidents involving infants occurred during Letby’s 33 training shifts at Liverpool Women’s Hospital in 2012 and 2015.
These revelations come amid months of criticism surrounding the prosecution’s case in her first trial. Several experts have questioned the medical evidence used in Letby’s conviction, as well as the statistical methods presented in court.
The nurse has been refused leave to appeal against the convictions from her first trial.
Panorama has examined mounting questions from leading statisticians and medical experts about the safety of her convictions.
But as part of the programme, new evidence has also emerged of other sick and premature babies potentially being harmed while in Letby’s care.
When the body produces insulin naturally, it also produces a substance called C-peptide. Typically, the level of C-peptide will be five to 10 times higher than the level of natural insulin.
Letby’s first trial heard blood tests from the two babies showed they had high levels of insulin and very low levels of C-peptide.
The prosecution argued the insulin must have been given to them rather than naturally produced.
Letby’s lawyers did not accept the insulin evidence used in court, but neither did they argue it was wrong. When she was cross-examined Letby herself accepted the two babies must have been poisoned, but denied it was done by her.
The new evidence seen by Panorama shows a blood test from a third baby being cared for by Letby in November 2015 also recorded very high levels of insulin and low levels of C-peptide.
Lab results indicated the insulin level was in excess of 6,945 picomoles per litre – a very high reading. Had the insulin been natural, the C-peptide level would have been between 35,000 and 70,000, but the blood test showed it was just 220.
At the time, consultants on the neonatal unit assumed the insulin must be natural. Tests later revealed the baby had congenital hyperinsulinism (CHI) – a condition where the body naturally produces too much insulin.
But four experts have told Panorama that CHI could not explain such an exceptionally high insulin reading for the infant – partly because of the low C-peptide level, but also because a baby with CHI would never produce that much insulin.
Medical records seen by Panorama show how quickly the boy became poorly after Letby came on duty. A blood test taken at 06:56 showed the infant had a normal blood sugar level of three millimoles per litre (mmol/L).
Letby started her shift at 08:00, and by 13:54 his blood sugar level had plummeted to one mmol/L – a dangerously low level, and a strong indication the baby had too much insulin.
The boy’s blood sugar level remained low throughout the nurse’s shift and he only recovered after she went off duty at 20:00.
