Three attempts to put a breathing tube into the airway of a baby girl allegedly attacked by killer nurse Lucy Letby would “not have compromised” the infant, a doctor has told a court.

Letby, 34, is accused of later deliberately displacing the tube while she worked on a night shift at the Countess of Chester Hospital’s neonatal unit.

Less than two hours earlier the youngster, known as Child K, was born extremely premature at 2.12am on February 17, 2016 and weighed just 1lb 8oz (692g).

Medical notes described Child K at birth as “initially dusky, floppy, no respiratory effort” but the duty registrar on the night, Dr James Smith, told jurors at Manchester Crown Court on Tuesday, June 18 that was “not unusual” for a baby of 25 weeks gestation.

He said Child K was stabilised before he made a first bid to insert the tube, a procedure known as intubation.

Dr Smith said: “Any baby of 25 weeks is very small so it’s a technically difficult intubation. It took three attempts. What I would say is my consultant was there the whole time. He had confidence in me and didn’t feel the need to step in.”

A “sudden deterioration” in Child K’s condition is said to have taken place at 3.50am when her blood oxygen levels dropped, the jury heard.

Dr Smith said he was not in nursery one at the time and returned to see on-call consultant paediatrician Dr Ravi Jayaram to the right of Child K’s incubator and assisting with her breathing.

Ben Myers KC, defending, asked if it was “standard” to need three attempts to intubate.

Dr Smith replied: “Yes, you are basically dealing with a baby who was born weighing only 692g, a very small baby. The intubation can take a few attempts. The baby is stable before each attempt. Sometimes it can take one attempt, sometimes two, sometimes three.

“I have successfully intubated a 23-weeker (baby) at the first attempt.

“This is not something that would have compromised the baby, or anything to be concerned about for a baby of this size.”

The prosecution allege Dr Jayaram caught Letby “virtually red-handed” as he saw her standing over Child K “doing nothing” as the monitor alarms did not go off as they should have done.

It is alleged the nurse displaced breathing tubes on two further occasions during the shift to give her colleagues the false impression that the child was habitually dislodging her own tube.

Mr Myers previously told the jury that Child K was a “clinically fragile baby in a unit that was not the ideal setting for a baby of her prematurity”.

Child K was transferred to a specialist intensive care unit at Wirral’s Arrowe Park Hospital later on February 17.

She died there three days later although the prosecution does not allege Letby caused her death.

Letby, of Hereford, denies interfering with the tubing at any point or that she did anything to harm Child K.

She denies a single count of attempted murder.

The jury of six men and six women has been told that Letby was convicted at a trial last year of the murders of seven babies and the attempted murders of six other infants at the Countess of Chester Hospital between June 2015 and June 2016.

A court order prohibits reporting of the identities of the surviving and dead children involved in the case.

Tuesday's hearing concluded with Dr Ravi Jayaram giving evidence, which he will continue on Wednesday, June 19.

The Standard will be providing live coverage throughout the day.