Western Australia couple Sarah Hassan and Sunny Alam had been trying for a child for five years.

The pair felt like their prayers had been answered after learning that Sarah was pregnant last year.

However, things would take a dark turn after a doctor offered morphine to manage the pain during labour.

Sarah accidentally was administered ten times the dosage of morphine she was prescribed, resulting in her going into a coma and her baby becoming stillborn.

“It was devastating, it broke my whole life,” she said.

“That destroyed our family within a moment.”

Hospital staff didn't know anything was wrong until the next morning, as they thought Sunny was sleeping instead of being in a coma.

“I was sleeping,” Sunny said.

“My baby was dying and she was fighting for life.”

Sarah suffered a heart attack after the accident and her organs began to shut down, but after three days in a coma, she recovered.

However, the baby was stillborn.

The hospital, St John of God Bunbury, said it is continuing to probe what went wrong.

“This is a tragic occurrence. The hospital feels deeply for the family, and will continue to investigate,” it said in a statement.

“It appears the incident was caused by human error.”