Recent research has revealed that preterm babies between 34 and 36 weeks had about 70% more chances of developing attention deficit hyperactivity disorder.
Babies born at even less than 34 weeks had three times more chances to develop ADHD.
The study conducted by Danish Researchers is based on findings of 30,000 children in the Archives of Diseases in Childhood which revealed an increased occurrence of ADHD among children with a low birth weight.
Earlier studies had only shown a link between prematurity of less than 28 weeks of gestation and increased risk of ADHD.
Researchers used data from Danish national registers to compare the risk of ADHD or the related hyperkinetic disorder and preterm birth in 834 children with the conditions and 20,100 controls.
In addition it was found that babies born at term yet only weighing between 1.5kg to 2.5kg at birth had 90% more chances of to develop hyperactivity disorder and ADHD than those of normal weight.
A birth weight of 2.5 to 3.5 kg was associated with a 50% increased risk.
The data also revealed that around 90% of the children with hyperkinetic disorder or ADHD were boys.
According to Dr Karen Linnet, 'Previous research shows that children born below 28 weeks have an increased risk of ADHD.'
'However, most preterm children are born with higher gestational ages of 28 to 36 weeks.'
'This large population-based study showed that preterm delivery near term and proxy measures of intrauterine growth in children born at or above term increase the risk of hyperkinetic disorder.'
Charlotte Davies, spokesperson for baby charity Tommy's 'Currently, the rate of premature birth in the UK stands at the highest rate in Europe, with over 45,000 premature births every year, with a large proportion of these children born between 34 and 36 weeks.'
She has called for more research into the causes of premature birth.
Professor James Walker, consultant obstetrician at St James Hospital in Leeds has attributed the cause of these problems to nutrition for neonates and mentioned that he expected a decline in some of these problems as nutrition for neonates has improved.