Friday March 13 2009
The study looked at extremely preterm babies born at less than 26 weeks
“More than half of children born before 26 weeks need extra help at mainstream schools,” reports BBC news today. The Daily Telegraph reports that academics believe that these extremely premature children should be allowed to start school later because they take longer to develop.
This research enrolled 219 children born extremely prematurely in 1995. Eleven years later, it compared their academic attainment and special educational needs with 153 similar-aged children born after a normal pregnancy. It found that extremely premature children had significantly lower scores than their classmates in cognitive ability, reading and maths. It also found that 132 (about two–thirds) of the extremely prematurely children required special needs help at school or were at a special school compared to 17 (about 11%) of similar aged term babies.
These results highlight the need for special educational help for these children, but because they were born 14 years ago, it is likely that the situation and care for children born extremely prematurely nowadays will have improved. The results do not directly apply to premature babies born after 26 weeks. The researchers say that these babies are likely to be less severely affected.
Where did the story come from?
Dr Samantha Johnson and colleagues from University College London and the Universities of Nottingham and Warwick carried out this research. The study was funded by the Medical Research Council. The study was published in the peer-reviewed medical journal Archives of Disease in Childhood: Fetal and Neonatal Edition.
What kind of scientific study was this?
This cohort study involved children who had been born extremely prematurely, and it assessed their academic attainment and special educational needs at 11 years of age. Extremely preterm babies were defined as those born at less than 26 weeks (technically up to and including 25 weeks and six days).
The researchers say that extremely preterm babies and those born at extremely low birthweight are at risk of having disabilities later in life. Cognitive impairments are the most prevalent disability at school age, and these can contribute to problems with learning and poor academic attainment, even among children without serious physical disabilities or cerebral palsy.
The researchers were part of a team that set up the ongoing EPICure study. This study is aimed at determining the survival chances and later health status of preterm babies. It follows up children born in the UK and Ireland at less than 26 weeks gestational age during a 10-month period in 1995. The children have already been assessed at one year, 2.5 years and 6-8 years of age. This is the report of findings at the 11-year assessment.
At the 11-year assessment, the researchers analysed the data on 219 of the original 307 surviving extremely premature babies (71%). This was compared with a comparison group of 153 classmates born at term, using standardised tests of cognitive ability (the Kaufman-Assessment Battery for Children and a Mental Processing Composite score). The researchers also used the Wechsler Individual Achievement Test 2nd Edition, which measures reading and maths ability to test educational attainment. A further test assessed intuitive mathematics (for example, how well the children estimated numbers of dots in a picture or lengths of lines). Teacher reports of school performance in seven subjects (score range 1 to 5, averaged across subjects) was used to determine whether children were performing below the average range (score <2.5). Teachers also identified those children with special educational needs.
Parental socioeconomic status was assessed, and standard statistical tests were used to estimate the prevalence of serious cognitive impairment (a mental processing composite score of less than 82) and learning impairment (a reading score of less than 74 and a maths score below 69).
What were the results of the study?
The researchers report that the extremely premature children had significantly lower scores than classmates for cognitive ability (20 points lower), reading (18 points lower) and mathematics (27 points lower). Twenty-nine (13%) of the extremely premature children attended special school.
In mainstream schools, 105 (57%) of the extremely premature children had special educational needs, and 103 (55%) required special teacher help. Of the classmates who were born at term, 17 (11%) had special educational needs and required extra teacher help. Teachers rated 50% of extremely premature children with educational attainment below the average range, compared with 5% of classmates born at term.
Just over a third of the extremely premature children in mainstream school (68 children, 36%) attended school a year earlier than they would have done if they were born at term. These children had similar academic attainment to the rest of the children born extremely prematurely, but required more special educational needs support.
What interpretations did the researchers draw from these results?
The researchers say, “extremely premature survivors remain at high risk for learning impairments and poor academic attainment in middle childhood.” They go on to describe the implications of this:
- A significant proportion require full-time specialist education.
- Over half of those attending mainstream schools require additional health or educational resources in order to access the national curriculum.
- The prevalence and impact of special educational needs is likely to increase as these children approach the transition to secondary school.
What does the NHS Knowledge Service make of this study?
This study gave extremely premature babies higher estimates of serious impairment at reading and maths than similar (population-based) studies. The authors say that this is because they included only extremely immature births (which in 1995 had poorer survival than now), and that for these babies a higher level of impairment would be expected given the “gestational age-related gradient in cognitive function”.
They say this means that it is likely that premature babies born later (between 26-37 weeks) would not have this degree of impairment. This includes the vast majority of premature babies, which is a group that the researchers did not examine.
The researchers acknowledge that the difference in impairments may have been overestimated because the control group came from mainstream schools and it was not possible to have a comparison group of children born at term who attended special schools. However, the researchers also argue that underestimation is possible because children with serious cognitive deficits and functional disability may have been more likely to be lost in the follow-up process.
Overall, this study has shown a high prevalence of learning difficulties in children born extremely prematurely, and that this clearly affects their school performance and educational needs. The authors say this could justify changing the UK policy of compulsory formal schooling beginning in the term after a child's fifth birthday. Some newspapers have picked up on the possibility of delaying starting school for children born extremely prematurely as a strategy for reducing the impact of these learning difficulties.