Neurodevelopmental, psychiatric, and behavioural problems and disorders in children born extremely preterm: Have outcomes improved over time?

Children born extremely preterm (EP) are at increased risk of neurodevelopmental, psychiatric, and behavioural morbidity. Survival for EP babies has improved over the past three decades; however, it is not known whether neurodevelopmental, psychiatric, and behavioural outcomes for EP children have changed over this time. This thesis addresses this by comparing the prevalence of attention, emotional, social, and behavioural problems and neurodevelopmental, psychiatric, and behavioural disorders in two prospective national cohorts of children aged 11 years born EP in 1995 (EPICure) and 2006 (EPICure2), alongside contemporaneous term-born children.

Behavioural problems were assessed using the Strengths and Difficulties Questionnaire (SDQ), DuPaul Attention-Deficit/Hyperactivity Disorder Rating Scale (ADHD RS) and Social Communication Questionnaire. In both cohorts, EP children had higher mean scores and more clinically significant difficulties than term-born children on almost all measures. There were no significant differences between EP children in the two cohorts in mean scores or the proportion of children with clinically significant difficulties after adjustment for confounders. Using contemporaneous term-born children as reference, EP children in EPICure2 had significantly higher SDQ total difficulties and ADHD RS hyperactivity-impulsivity z-scores than EP children in EPICure.

The Development and Well-Being Assessment (DAWBA) was used to assign research diagnoses of neurodevelopmental, psychiatric, and behavioural disorders. EP children in both cohorts were significantly more likely than term-born children to be assigned a diagnosis of any disorder, emotional disorders, attention-deficit/hyperactivity disorder, and autism spectrum disorder. EP children in EPICure2 were also more likely to have conduct disorder than term-born children. There were no significant differences in the rates of any disorder between EP children in the two cohorts.

Increased survival has not translated into improved neurodevelopmental, psychiatric, and behavioural outcomes. Healthcare professionals and educators need to be aware of this ongoing risk and children born EP need long-term neurodevelopmental and psychological follow-up and support.