Hundreds of thousands of premature babies have been saved by a breakthrough Kiwi discovery.
New Zealand scientist Sir Graham 'Mont' Liggins discovered in the 1960s that a steroid injection given to mothers dramatically improves survival rates.
Now researchers hope their latest findings could double the number of babies that benefit, like Connor Jenkins.
Connor is a happy, healthy, 13-year-old. But he took his parents by surprise.
"My waters broke at 16 weeks so we knew he was going to be very early," says mum Hilary Jenkins.
Connor was born at 27 weeks, weighing just 850 grams.
Having already had one premature baby, Ms Jenkins knew there were risks.
"It was really important for us to have any advantage we could for him to have the best start."
New Zealand researcher Sir Graham Liggins and Dr Ross Howie pioneered the use of corticosteroids - discovering that giving mothers steroid injections speeds up the development of babies' lungs, cardiovascular and immune systems.
And they believed giving a repeat dose after seven days would give even more benefit.
"The big question that we haven't known until now was how much to give, and if we give more, is it safe?" says Dr Chris McKinlay a neonatal specialist and researcher at the Liggins Institute.
While single courses are routinely given to women identified as at-risk of preterm birth, not all at-risk women are receiving repeat doses due to lingering concerns that the powerful steroid hormones could have long term adverse effects on health.
Now scientists have the results of a 15-year-study involving 1000 babies.
"Everything that we've looked at has shown no adverse effect whatever so we're very confident that this treatment is safe," says Dr McKinlay.
Ms Jenkins says despite being born five weeks more premature, Connor's had fewer problems than his elder brother and she puts that down to the steroids.
Older brother Ryan teases him, calling him a 'scientific experiment', but Connor prefers to think of himself as a 'scientific asset'.
Researchers hope that the latest findings will completely reassure doctors about the short term benefits and long-term safety of repeat doses.