The number of children with complex disabilities is increasing and experts blame pre-term births and fetal alcohol syndrome as two key factors.
Figures obtained by the Herald on Sunday revealed more than 60 per cent of schools designated for children with severe, mild and complex learning difficulties and disabilities had increased enrolments during the past five years.
Kapiti's Central Regional Health School enrolled 88 students in the past five years compared to 16 in the previous five years.
Auckland's Rosehill School in Papakura and Christchurch's Southern Regional Health School have almost doubled the amount of students enrolled since 2007.
Specialist consultant and director of Positive Path International, Jane Thistlethwaite, said the rise was due partly to an increase in pre-term babies and longer survival rates in children with disabilities.
Figures from the Ministry of Health showed a 17 per cent increase in babies born before 37 weeks during the past 10 years.
Auckland City Hospital senior pediatrician Dr Simon Rowley said New Zealand was following a worldwide trend with an increasing number of late pre-term births due to medical interventions.
Rowley said late pre-term babies were likely to develop mild learning difficulties and extreme pre-term babies born before 32 weeks could develop severe disabilities, including cerebral palsy and autism.
"The biggest increase has been in the late pre-term, which is 34 to 37 weeks' gestations, and they contribute to children with increasing educational needs," said Rowley.
"Some of that increase is due to intervention, people are having babies early because they are worried about pregnancies ... or when Mum gets sick you have to take baby out because she is going to die or has severe toxemia."
Rowley said another contributing factor could be fetal alcohol syndrome disorder but had no evidence because New Zealand did not calculate statistics.
Fetal Alcohol Network co-ordinator Christine Rogan said 28 per cent of women drank alcohol during their pregnancy - four times higher than women in the United States.
She said children born with fetal alcohol syndrome often had severe behavioural difficulties.
Fighting all the way
Kimberley North came out of her mother's womb fighting for air and had a cyst on her brain.
Her arrival began at just 26 weeks' gestation, but doctors delayed her birth for a further eight weeks and pumped steroids into her tiny body.
Her mother, Christine, 36, said: "We were told the chances of her survival were all about her coming out fighting."
Born at 2270g, Kimberley spent five weeks in an incubator before going home.
Sixteen years later, she has developed into a confident and happy teenager who still deals with the complications of being born premature.
Kimberley has epilepsy, which causes seizures about four times a month, and struggles at school.
Christine said the increase in pre-term babies was alarming.
"You have to wonder why. It's a concern because it is a huge long-term cost on society."