A third person has died following a horror multi-vehicle collision in Pakenham South earlier this month.
Investigators believe a white ute collided with a silver SUV on Healesville-Koo Wee Rup Road about 8am on Thursday, February 4.
The sole occupant of the utility, a 62-year-old Narre Warren North man, was airlifted to hospital with life-threatening injuries but sadly died last week.
The female driver of the SUV also sustained life-threatening injuries and was airlifted to hospital in a critical condition.
Tragically, the 34-year-old Koo Wee Rup woman and her unborn child died in hospital shortly after.
Her two passengers, both young children, sustained non-life-threatening injuries and were transported to hospital as a precaution.
Casey Highway Patrol officers will prepare a report for the Coroner.