It could be the world's longest milk run.
When severely premature baby Levi Atkinson was airlifted from Darwin to Brisbane to receive specialist care at the Mater Mothers' Hospital, litres of his mum's precious frozen breastmilk stayed behind.
New mum Tegan Wain kept expressing breastmilk after flying to Brisbane to be with her son, but the stress of having a severely premature baby — born 16 weeks early at the Royal Darwin Hospital on June 22 — meant her supply began to fade.
Wanting to give Levi the best start in life possible, the Mater launched a mission to bring about 150 bottles of Ms Wain's breastmilk, stored in a freezer in her Darwin home, to Brisbane.
On Tuesday, after a 24-hour, 4,200-kilometre journey from Darwin via Adelaide, a large icebox containing Ms Wain's breastmilk arrived at the Brisbane hospital for Levi, who was born weighing just 740 grams.
Levi was flown to Brisbane on July 25 for expert care after complications developed following three-and-a-half-hour surgery in Darwin to remove a section of his bowel that had perforated twice – a symptom of prematurity in some babies.
Mater director of neonatology Pita Birth said given Levi's "challenging" start to life, it was considered important to access Ms Wain's breastmilk.
"That early breastmilk has got a lot of really important properties in it," Dr Birch said.
"He needs that milk to help his gut develop and help his gut stay healthy, help him grow and get the immune benefits.
"Giving him the maximum amount of breastmilk that he can possibility have is going to be better for his long-term future.
"It's a really nice story that we were able to get this milk that is so precious … all the way from Darwin to Brisbane – the length of multiple countries in Europe – for use in this baby."
Ms Wain said Levi tipped the scales at 2,592g during his last weigh-in and "is doing amazing" despite being born at 24 weeks.
"He is our little warrior," she said.
Levi still has eye and lung problems because of being born so prematurely and requires another operation before Christmas to reverse a stoma – a section of bowel brought out through an opening in the abdomen to remove faeces – created during his surgery in Darwin on July 11.
But Ms Wain, a first-time Mum, and fiance Rodney Atkinson, who has two older sons, hope to first be able to take Levi home to Darwin before returning to Brisbane for the operation.
"Both of us are feeling a lot more settled," Ms Wain said, adding there were numerous times she feared Levi may die in the early weeks following his birth.
At four days old, when Levi developed a severe infection, doctors gave his parents a choice whether to give him antibiotics or not.
"We were informed that it was pretty likely that he wasn't going to get through the infection," Ms Wain said.
"But we had always said from before he was born that if he showed fight, then we'd fight with him — we needed to give him the best possible chance."
The 37-year-old said she had "no words" to describe how she felt about the staff at both the Royal Darwin and Mater Mothers' hospitals.
"Grateful is an understatement," she said.
"They're always concerned as much for you as what they are for your baby.
"They get just as excited over the wins as you do and just as concerned over the hiccups.
"They've just done an incredible joint job to get Levi to where he is today."
The Mater Foundation and the Royal Darwin Hospital jointly funded the $1,025 in transport costs to get Ms Wain's frozen breastmilk to Brisbane.
