A vital blood sample that would have flagged the seriousness of Savita Halappanavar's condition earlier was not sent to the lab for three hours.
When the results were finally provided at 9pm on Wednesday, October 24, they revealed that the 31-year-old dentist was suffering a serious bacterial infection.
While Ms Halappanavar was on the correct antibiotics from lunchtime that day, it's not clear whether she was on the correct treatment for the critical hours after doctors first found evidence of sepsis at 6.30am the same day.
Questions were raised yesterday by both the coroner and lawyers for Praveen Halappanavar as to why the blood sample, which was taken at 7am on Wednesday, was not sent for testing until 10.12am.
The sample of bacteria taken from the blood would always take a minimum of seven hours to grow in the lab.
Coroner Dr Ciaran McLaughlin described the delay as "another risk factor".
The inquest heard from Dr Deirbhile Keady, a consultant microbiologist, that antibiotics given to Savita from lunchtime onwards were correct. She gave evidence of a telephone conversation with Dr Katherine Astbury at between 1.30pm and 2pm in which it was decided to add to the antibiotics.
She told the inquest these antibiotics appeared to be working and she would not have changed them even if she had received the results from the blood test earlier than 9pm that night.
When the results were finally made available at between 8.30pm and 9pm that night, the course of antibiotics remained the same and Ms Halappanavar was responding to the treatment, Dr Keady told the inquest.
However, when it was put to her by Dr McLaughlin that there had been a delay of several hours in initially providing the sample to the lab, she replied: "Okay, then that would be a concern."
Barrister Eugene Gleeson also questioned why Ms Halappanavar had not been placed on the new antibiotics earlier than 2pm, stating that "time was of the essence of this case".
Dr Keady agreed that time was of the essence in a case like this. She was unable to shed any light as to the reason for the delay in the sample being sent to the lab.
By the next morning, it had become clear that it was a probable ESBL E.coli infection. Dr Keady told the inquest that such an infection was "very uncommon" in a maternity setting.
The inquest also heard from Dr Aidan Magee, who was asked to bring Ms Halappanavar to theatre to insert an IV line into her neck. He revealed he had no knowledge of plans to induce the foetus.
The senior house officer at the hospital brought Ms Halappanavar to theatre on Wednesday afternoon.
When asked by Mr Gleeson whether there had been any discussion to induce labour, Dr Magee replied: "I didn't have any discussion with anybody about that."
The inquest previously heard evidence from Dr Katherine Astbury, who claimed the foetus was to be induced at that stage.
Earlier, the inquest heard of the final hours of Ms Halappanavar's life as medical staff gave evidence of their efforts to save her.
ICU staff nurse Jacinta Gately gave evidence of having been with Savita through her final hours on the night of Saturday, October 27, and the morning of Sunday, October 28.
Ms Gately told the inquest that as Savita's condition had deteriorated throughout the Saturday night, she spoke on several occasions to Mr Halappanavar, who was in a waiting room with friends.
She told the inquest that she was aware Praveen was "anxious" to see his wife.
As she deteriorated, Ms Halappanavar was given blood and platelets, was ventilated and placed on dialysis. An arterial line was inserted and she was given adrenaline infusions.
"I went to the waiting room to meet Ms Halappanavar's husband Praveen at some time between 21.30 and 22.00.
"I explained what we had been doing and brought him and some friends in to see Ms Halappanavar," said Ms Gately.
At between 12.30am and 12.45am, Savita's heart rate became chaotic, with a "broad spectrum rhythm". Medics could find no pulse and CPR was commenced.
"Within minutes of commencing CPR, I went out to find Mr Halappanavar to let him know what was happening, that his wife's heart had stopped and that we had started CPR," she said.
However, despite their best efforts to revive Savita, she passed away, with the time of death recorded as 1.09am on Sunday, October 28, 2012.
Earlier, theatre staff nurse Noreen Hannegan gave evidence of Ms Halappanavar spontaneously delivering the foetus of her baby daughter when she was brought to theatre to have a central line inserted on Wednesday, October 24.
Ms Hannegan told how neither she nor her colleagues had expected this but told how after the line was inserted they had given the couple time to grieve.