Population Based, Controlled Study of Behavioural Problems and Psychiatric Disorders in Low Birthweight Children at 11 Years of Age

Abstract

The long-term risk of behavioral and psychiatric disorders associated with low birth weight was assessed in 130 low-birth-weight (LBW) children who weighed less than 2000 g at birth but who had no major handicaps at age 11 years. The control group included 131 normal-birth-weight (NBW) children whose birth weight exceeded 3000 g. Mothers and teachers completed validated questionnaires dealing with behavior. The Yale Children's Inventory served to assess attention deficit hyperactivity disorder (ADHD). Social skills were evaluated using the psychometric scale of the Asperger Syndrome Diagnostic Interview. In addition, children were evaluated by a child psychiatrist in a semistructured interview based on the Children Assessment Schedule (CAS). This instrument covers such areas as friends, school, activities, family, anxiety, self-esteem, somatic complaints, aggressive behavior, and problems in thinking. Psychometric intelligence was significantly lower in LBW than in NBW children. Parental educational levels were lower in LBW families, and parental stress was rated as somewhat higher. Child rearing was more often assessed as being less nurturing. Mothers of LBW children more often smoked during pregnancy. More LBW than NBW children scored abnormally in attention, social problems, and anxiety/depression. Asperger syndrome was diagnosed in a single LBW child. Teachers reported that more LBW children had abnormal scores for social and attentional problems and delinquent behavior. CAS findings pointed to more problems in school as well as leisure-time activities for the LBW children, as well as more aggressive behavior and lower self-esteem. Total problem scores were abnormal in 40% of LBW children and 7% of the NBW group and changed little after adjusting for child intelligence and possible confounding parental factors. Psychiatric disorder was diagnosed in 27% of LBW children and 9% of NBW children. Of the 33 LBW children affected, 13 had ADHD. Apart from ADHD, which was more prevalent in boys, there were no significant gender differences within the LBW group. Multiple logistic regression analysis failed to identify any prenatal or neonatal factors that predicted behavioral or psychiatric problems at age 11. This study revealed an increased risk of both behavioral and psychiatric disorders persisting at least to early adolescence when birth weight is less than 2000 g. The study demonstrated no interaction between birth weight and parental risk factors.