A study published today in the journal Paediatrics has taken the research a step further - by confirming that giving pregnant women at risk of having premature babies multiple doses of corticosteroids can further improve premature babies' health.
The Australasian Collaborative Trial of Repeat Doses of Corticosteroids (ACTORDS) study conducted by researchers at the University of Auckland's Liggins Institute and the University of Adelaide tracked the health and development during the first eight years of life of 1000 premature babies whose mothers were given either repeat doses of the steroid or a placebo.
The study's results show that steroids are most effective when the mum gets multiple doses over several weeks, one of the researchers, Middlemore Hospital neonatologist Dr Chris McKinlay, said.
"That has quite dramatic benefits for the baby if they're born too early and too small. The main risk if they're born very pre-term is that their lungs are quite immature and so they often need assistance breathing, like to being on a ventilator, and if we give one dose it reduces the risk by about half and if we give repeat doses it's about twice as effective again."
Paediatricians had previously been hesitant to give pregnant women multiple doses of corticosteroids because of fears that exposure to steroids could damage the babies' health long-term after past animal testing linked repeat doses to later health problems in animal offspring.
But now ACTORDS researchers have found no differences in the survival rates, health, development and body size of children whose mothers had received repeat steroids and those who had not.
"What we've shown in our study is that we're very confident there are no long term adverse health effects on bone growth - because one of the concerns was that exposing babies to steroids might put them at risk of osteoporosis when they grow up," McKinlay said.
Up to 2000 women a year who are at risk of having pre-term babies could be eligible for a treatment programme of repeat doses of corticosteroids funded by the Government, McKinlay said.
A pregnant woman could be considered at risk of delivering prematurely for many reasons, including if the baby wasn't growing, the mother's water had broken early or the woman had previously had a baby born pre-term.
Connor's story
You'd never guess by looking at Connor Jenkins that he was born 13 weeks before his due date.
He was one of the 1000 babies involved in the ACTORDS trial.
His mum Hilary Jenkins was only 16 weeks' pregnant with Connor when her waters broke.
Having already had one premature baby - Connor's older brother Ryan was born at 32 weeks' - Hilary and her husband Stephen recognised that her water breaking was a sign that Connor could come early.
"Ryan had been sick with things like [chest colds] when he was a baby so we were pretty keen to do anything to make sure Connor had the best start, like a little bit more than Ryan had because we didn't know [Ryan] was going to be early."
At 26 weeks' gestation Hilary went into hospital and got her first shot of steroids. Shortly after being admitted she found out about the trial and signed up.
"I was pretty keen to do anything we could to help him along," she told the Weekend Herald.
Connor was born at 27 weeks' gestation. He had a few battles when he was first born.
"His lungs collapsed and he was on a big ventilator - that was very scary," Hilary said.
"I think the steroids helped him, you only need a really little help sometimes to make a big difference."
Apart from being of small stature his premature birth hasn't had any long term effects on Connor, who's now 13.
The proud mum says that both her boys are "very smart" kids.
But Ryan, now 16, has had to face more long term health battles than his brother including attention deficit hyperactivity disorder (ADHD), which is common in children born prematurely.
Getting corticosteroids when Hilary was pregnant with Ryan wasn't an option because they didn't know he would be a premature baby.
Her advice to mothers who were at risk of having a pre-term baby was to take go through the steroid treatment if it was available.
"It's a pretty tough road for all the mothers with little premmie babies, for years. So anything you can just grab it with both hands because it's well worth it."
