Prof Sabaratnam Arulkumaran, the chair of the inquiry into Savita Halappanavar's death in 2012, has called for a Yes vote in Friday's Eighth Amendment referendum.
31-year-old Savita, who was 17 weeks pregnant, died at University Hospital Galway from sepsis while suffering a miscarriage.
An investigation found the Eighth Amendment played a role in her death after her request for an abortion was denied.
Those on the No side of the Referendum debate have said her case is being misrepresented.
However, Prof Sabaratnam Arulkumaran says it was the constitutional ban on abortion which prevented Savita from being treated properly.
Speaking in Dublin today, he said: "If she had had [a termination] two days earlier, she would have been alive. By waiting and going into septic shock, it became too late to save her life.
"Just the fact that the health personnel were wanting to listen to the baby's heart that morning when she was severely sick... just indicates how worried the health personnel were in terminating the pregnancy."
His comments come after Savita's parents also called for a Yes vote in Friday's referendum.