Palmer then learnt that she had a "molar pregnancy" which occurs when the cells that normally form a placenta develop into normal cells and can be "potentially cancerous", the actress also shared.
"I needed surgery immediately. I was whisked away into the operating theatre to have a D&C [dilation and curettage].
"It was the first time I'd ever been in hospital," she continues.
"It was the most terrifying, traumatic and grief filled experience we've ever been through. It still haunts us."
16 months later, Teresa welcomed her second son Bodhi.
The Adelaide-born beauty shares two children with husband Mark. She is also a stepmum to Mark's son Issac, whom he shares with actress Frankie Shaw.