The Dublin City Coroner's Court hearing into 31-year-old Nora Hyland's death heard that an emergency supply of blood was not kept in the operating theatre at the time.
Ms Hyland, a Malaysian woman living at Charlotte Quay in Dublin 4, died on the operating table on February 13, 2012, having suffered a cardiac event an hour after the c-section.
Her husband, Stephen, told the court that the baby, Frederick, was their first child and he was doing well.
The barrister for the family, Sara Antoniotti, told coroner Dr Brian Farrell that a hospital review following the incident made a number of recommendations relating to the availability of blood.
The court heard that an emergency c-section was carried out on Ms Hyland on February 12 after a drop in the foetal heart rate was recorded at 11.05pm.
Dr Nikhil Purandare, then specialist registrar in obstetrics at the NMH, successfully delivered the baby and closed up the abdomen.
At 12.03am, he noted that Ms Hyland had lost approximately one litre of blood.
He requested that blood be ordered from the lab, starting with O-negative blood, while units matching Mrs Hyland's type were sourced.
Dr Purandare said he would have expected the O-negative blood to arrive more quickly. When consultant obstetrician Dr Shane Higgins arrived at 12.28am, he decided that a laparotomy – or exploratory surgery – was necessary to stop the bleeding.
Dr Purandare had earlier told the court that blood loss was estimated at 3.5 litres following this procedure. The blood transfusion began at 12.40am – 37 minutes after he had ordered it.
The patient was considered stable following the laparotomy. However, at 1.05am she suffered a sudden collapse. Resuscitation attempts failed and she was pronounced dead.
Mr Higgins said Ms Hyland's blood pressure, pulse and oxygen levels were normal before her collapse. The hospital has been unable to establish the cause of death, he told the court.
Ms Hyland was estimated to have had 5.5 to six litres of blood circulating in her system.
Under cross-examination, Mr Higgins conceded that a loss of 3.5 litres of blood would be "an enormous insult".
It would have been preferable to have hung the O-negative blood "much sooner", he said, and probably before he had arrived in theatre.