In a hurry to catch up
Connor McCallum was the surprise of his parents' life and when he joined the world in May his future looked uncertain.
He weighed 620 grams at 27 weeks. If his father had been able to hold him, he would have fitted into the palm of his hand.
His mother, Lecia McCallum, said: "He was perfectly formed. He was just very, very small. I didn't get to hold him until he was 21 days old."
The newest addition to the family spent more than 15 weeks in Christchurch Women's Hospital's neo-natal intensive care unit. "We had the most brilliant care. We wouldn't have a baby if it wasn't for them."
Connor now weighs 5.5 kilograms - 25 weeks after his caesarean-section birth. McCallum said he was "doing well", despite having chronic lung disease, hernias and ongoing brain issues.
"He's too little [for us] to know if his mental function is going to be impaired in any way. He's on a monitor that lets us know if he stops breathing."
Connor's early months coincide with the release of new research on "very low birth-weight" babies by Christchurch-based Professor Brian Darlow.
Darlow has followed 230 New Zealanders born in 1986 weighing less than 1.5 kilograms alongside a control group of 69 babies born at 40 weeks.
His latest study, published in the Pediatrics journal this week, said very low birth-weight babies tended to be shorter, lighter and have fewer friends by the time they reached their 20s.
It also showed they were half as likely to have tertiary qualifications and almost a third more likely to have been dependent on welfare.
McCallum said Connor was displaying "very normal baby tendencies" and she had high hopes for his future.
Darlow's research indicated very low birth-weight babies were as happy with their quality of life as their control-group peers by the time they reached their 20s.
There were also no significant differences when it came to high school completion, involvement in paid employment and overall functioning.
McCallum said: "Connor is doing all the things he should be doing."
Connor was not the first of McCallum's three sons to be in a rush to join the world.
His brother, Jared, 12, was born weighing less than 1.5kg at 30 weeks.
Jared had learning difficulties and few close friends, which was in line with Darlow's research, but he was making "huge gains" with learning support.
"We found [Darlow's research] really interesting. There were some things that we could identify as being part of our 12-year-old's life. He was twice the size of Connor, but still below the very low birth-weight mark."