A Sydney hospital has apologised to a mother who was forced to give birth in the car park.

Paula Bailey says her harrowing experience at Nepean Hospital was made even worse by the way staff treated her.

Paula and her husband Scott tried for five years before falling pregnant with their second child Madison.

Earlier this month, they went to Nepean Hospital late at night with Paula having contractions.

After she was monitored, a midwife told Paula to go home, but she insisted that she was in pain.

"You'll know when you're in labour, suck it up princess," the midwife apparently replied.

Paula said she was gob smacked by what she had heard.

The couple went home only to return when Paula's waters broke.

With Paula in pain in their car in the parking lot, Scott tried the after-hours buzzer.

"Paula was yelling at me the baby's coming, I can feel the head I need to push," he said.

Scott then turned to the car to assist and cried for help. Someone did emerge from the hospital to ask what was going on, and then went back inside.

By the time a team from emergency arrived Madison had all but arrived. Dad was holding her head and shoulders.

Nepean Blue Mountains Local Health District chief executive Kay Hyman said the hospital regrets the couple’s experience.

“If [suck it up princess] was the comment that was made [that] would be inappropriate and that will be followed through,” Ms Hyman said.

Paula and Scott hope Madison's okay, but they'll never get over it.

"In the long run I just felt like they stole it away from me," Paula said.

"I don't deserve to be treated that way."

"It's not something you can get a refund on you know, it's a humans life they're playing with," Scott said.