Page 70 - Sample Moderate prematurity, socioeconomic status, and neurodevelopment in early childhood

Chapter 7
First, adverse family factors in the pre-school years may strengthen the effects of developmental delay on behavioural problems. As such, heightened levels of parental stress and negative parent-child interactions influence developmental delay as well as behavioural and emotional problems.41, 42 Due to the bi-directional relation between negative parenting and behavioural problems in children,43 an enduring downward spiral may ensue, and the risk of developmental delay co- occurring with behavioural and emotional problems may increase.
Second, co-occurrence of developmental and behavioural problems may be a consequence of disruptions in brain networks.40, 44 Children with specific brain network disruptions may be more vulnerable to exogenous or endogenous disturbances, resulting in a high risk of experiencing both developmental and behavioural problems. This hypothesis could explain why MP and late preterm- born children are more likely than full-term children to have co-occurring problems. Their lack of three to eight weeks of intrauterine brain development compared to full-term children may increase susceptibility to brain network disruptions.21, 22
Gender differences in behavioural and emotional outcomes
Gender is an important determinant in the assessment of behavioural and emotional problems. In general, boys are more likely to have externalizing problems and girls have more internalizing problems, which is similar in preterm children.32, 45, 46 Our results confirm these general differences between boys and girls. However, in contrast to our expectations, MP boys did not differ in behavioural outcomes compared to full-term boys. By contrast, MP girls showed significantly more behavioural and emotional problems than their full-term peers, as reported in Chapters 3 to 5. Previous reports on such gender differences between MP and full-term children are scarce. One recent study on precursors of symptoms of attention deficit hyperactivity disorder in 5-year-old MP children reported similar outcomes: preterm girls showed significantly more inattentive behaviour, hyperactivity, and impulsivity than full-term girls and boys, as rated by mothers and teachers.38 A significant interaction between gender and gestational age was also found, indicating a stronger association between preterm birth and behaviour problems in girls.38
In prior studies on MP children, a greater susceptibility of girls to moderate prematurity may have gone unnoticed because of insufficient sample sizes to perform stratified analyses. First of all, outcomes in MP girls have often been
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