Low birth weight associated with attention problems in children

The psychological effect of birth weight leads to the most attention problems in children aged 9 to 10, according to a recent study.

In previous studies, children with lower birth weights were seen with more symptoms of attention-deficit/hyperactivity disorder (ADHD). This study set out to model the continuous dose–response association between birth weight and psychological outcomes. 

Specificity was defined as one of the criteria for the study, to determine if the psychological effects caused by low birth weight are specific to attention problems. In many prior instances of association, other disorders were found in children, such as affective disorders, schizophrenia, substance-use disorders, and stress-related disorders. Because of this information, it is not certain that birth weight effects are specific to ADHD.

One study found that birth sex was associated with birth weight and issues of mental health that followed. Male children were more likely to have negative effects from lower birth weight than female children. Other studies contradicted this information, indicating that there was no difference in mental illnesses brought on by low birth weight between sexes. To address this contradiction, investigators tested for how sex might affect the outcome of the study.

Given the difference between gestational age and fetal growth, investigators wanted to determine which of these factors was associated with mental health issues because of low birth weight.

Data was analyzed from the Adolescent Brain Cognitive Development (ABCD) study, a study of children aged 9 to 10 years representing a wide range of demographic and socio-economic diversity within the United States. Just over 9000singleton-born participants wereselected to take part in the study.

Parents of the children in the study reported birth weight in pounds and ounces, which researchers converted into kilograms. If ounces were not included in the measurement, the number of pounds was rounded to the nearest number of kilograms. Children with an unlikely small weight or a gestational age lower than 28 weeks were excluded from the analysis.

Parents filled out a Child Behavior Checklist (CBCL) containing subscales on their children’s behavior patterns. These subscales included: anxious-depressed, withdrawn depressed, somatic complaints, social problems, thought problems, attention problems, rule breaking behavior, and aggressive behavior. The presence of autism spectrum disorder (ASD) was also noted in children. Finally, family history of mental illness and socioeconomic factors were asked about in the survey.

When examining birth weight, attention problems was the most common subscale noted. After controlling for gestational age alongside other variables, the only results observed were attention problems and somatic complaints. Of all the subscales, sex only had a major effect on attention problems, with male children having more attention problems than female children. ASD was also not associated with birth weight.

Investigators noted how the results of their study contrasted with prior studies. They recommended a variety of study designs on the subject.

Reference

Dooley, N., Clarke, M., Cotter, D. et al. Birth weight and childhood psychopathology in the ABCD cohort: association is strongest for attention problems and is moderated by sex. Res Child Adolesc Psychopathol 50, 563–575 (2022). doi:10.1007/s10802-021-00859-0