Moderated mediation of developmental coordination disorder on the relationship among Apgar score and executive functions at preschool and school ages

This study was to investigate the potential relationships between Apgar scores and EFs (e.g., inhibitory control, cognitive flexibility, and working memory) at both preschool and school-aged periods and how these relationships may be affected by DCD. 

This study included 69 children aged between 4 and 6 years (n=12 DCD). Agar scores at 1 (AS-1) and 5 minutes (AS-5) after birth were obtained from birth medical record. At baseline, motor coordination was assessed using the Movement Assessment Battery for Children – 2^nd edition, the result of which was used to identify motor difficulties. Inhibitory control and cognitive flexibility were assessed using iPad application of Early Years Toolbox, whereas working memory was evaluated using the digit span test. EFs were repeated assessed in all children two years later. In order to understand how DCD might impact the indirect effects of AS-1 and AS-5 on EFs at school age through EFs at preschool age, several moderated mediation models were examined with DCD as the moderator and sex as the covariate.

The results showed that there were no significant correlations between AS-1/AS-5 and EFs in all children; however, inhibitory control at school age was significantly associated with both AS-1 (r=.781, p.01) and AS-5 (r=.746, p.01) in children with DCD. Although there was no significant moderated mediating effect of DCD, there were significant interaction of AS-1 by DCD on inhibitory control at both preschool and school ages and working memory at school age, whereas there was a significant interaction of AS-5 by DCD on both inhibitory control and cognitive flexibility at school age.

To sum up, our findings suggest that the relationship between AS-1 and EFs at school age could be moderated by DCD. In other words, children with DCD who have the lower AS-1 may be at increased risk for poor EFs, specifically for inhibitory control. However, due to unbalanced sample sizes in children with and without DCD, further research is warranted by recruiting more children with DCD.

As poor executive function is evident in children with DCD, This study highlight the importance of the review of birth health, specifically Apgar score, in children with DCD, which may help early identification and intervention for those who might be at greater risk.