The odds were stacked against little Lottie before she even drew her first breath.

Diagnosed with congenital diaphragmatic hernia (CDH) at her 16-week scan, doctors told Caitlyn Browne and Dylan McKnoulty their baby had a “40-45 per cent chance” of surviving after birth.

Her diaphragm – the muscle separating the chest and abdominal cavity – hadn’t formed properly, meaning vital organs including her heart and stomach were in the wrong place, placing pressure on her lungs.

The first-time mum relocated from Albury-Wodonga to Melbourne four weeks before her due date so she could be near The Royal Children’s Hospital, and gave birth five days later on January 15.

After a “10-second cuddle” Lottie was whisked away and placed on a ventilator, where she would remain for eight weeks. Ms Browne remembers feeling “overwhelmed and emotional”.

“The CDH was a lot more severe when she born and she basically didn’t have a left lung at all,” she said.

“Her survival rate dropped, it was less than 30 per cent.”

That night she was moved to the RCH and Lottie Browne-McKnoulty and her medical team’s fight against the odds began.

She overcame two surgeries to move her organs after the first surgery was halted when she went into cardiac arrest, just six days old.

A week later she underwent a second successful surgery and then battled sepsis and a partial lung collapse.

But baby Lottie didn’t care about the grim odds, and months later her mum couldn’t hide her excitement as she updated the Herald Sun on her daughter’s “nice big step” – Lottie was breathing on her own for the first time.

Ms Browne said it took “a good while” to accept everything was OK. “Dylan just had to keep reminding me: she’s OK, she’s alive,” she said.

“I’ll be super emotional and crying and (Lottie) looks at me and smiles and starts talking to me. It’s like she’s trying to tell me, ‘It’s OK, I’m OK’.

“She just looks at me like I hung the moon in the sky.”

She said Lottie had grown into an “inquisitive” baby who won’t stop babbling. “She loves looking around and talking to everyone,” she said. “She just loves all her cuddles.”

She and Dylan survived the first few months by celebrating the “little wins”, whether it was the first time Lottie opened her eyes (at 16 days) or the first time they were allowed to hold her (at seven weeks).

“I was too excited while I was holding her, but while her dad was holding her I was crying,” she said.

Having had her daughter’s life saved by the Royal Children’s Hospital, Caitlyn’s wish for Lottie’s future is simple.

“I just want her to be a happy little kid,” she said.