**Background:** Developmental Coordination Disorder (DCD) affects approximately 6% of school-aged children and is characterized by poor motor coordination that interferes with daily activities and academic performance. Prior research has established that children born very preterm or with very low birth weight have 6–8 times higher probability of DCD compared to term-born peers. While parental socioeconomic status (SES) has been linked to both birth health and child motor development, no study had examined whether parental SES moderates the relationship between birth health and DCD. This study aimed to investigate differences in birth health and parental SES between children with and without DCD, and to test whether parental SES moderates the association between birth health indicators and DCD.
**Methods:** One hundred and twenty-two children aged 4–6 years were enrolled from six preschools in Taichung City, Taiwan, as part of the SMART prospective study. Motor coordination was assessed using the Movement Assessment Battery for Children—2nd Edition (MABC-2). Children scoring ≤16th percentile were preliminarily categorized into the DCD group (n=23; 17 boys, 6 girls; mean age 5.17±0.54 years), and those >16th percentile into the typically developing (TD) group (n=99; 47 boys, 52 girls; mean age 5.16±0.65 years). DCD diagnosis was confirmed using DSM-V criteria, including the MABC-2 Checklist (Criterion B), age verification (Criterion C), TONI-4 intelligence testing (no IQ<70), and parental medical history questionnaires (Criterion D). Birth health data (birth weight, birth length, head circumference, gestation age, Apgar score at 5 minutes, and birth weight for gestation age percentile based on Taiwanese norms) were retrospectively obtained from children's health booklets. Parental SES was assessed via questionnaire measuring paternal and maternal education level (3 levels), employment status (dichotomized as having/not having a job), and annual household income (12 levels, converted to continuous NTD values divided by 100,000 for analysis). Moderation analysis used the PROCESS macro for SPSS (Model 1) with 10,000 bootstrap 95% confidence intervals, controlling for child sex, age, and gestation age as covariates. Twenty moderation models were tested (4 birth health variables × 5 parental SES variables).
**Key Results:** There was a significant sex difference between groups (χ²=5.231, df=1, p=0.022), with more boys in the DCD group (boys:girls ratio 2.83:1 vs. approximately 1:1 in TD). MABC-2 total scores differed significantly (DCD: 55.78±10.34 vs. TD: 85.89±9.34, p<0.001). No significant group differences were found for any birth health variable (all p>0.05) or any parental SES variable (all p>0.05). Three significant moderation effects were identified: (1) Maternal education level moderated the relationship between birth length and DCD probability (unstandardized coefficient=0.6805, SE=0.3371, p<0.05). For mothers with lower education (high school/college/technical school or undergraduate), shorter birth length was associated with higher DCD probability; for mothers with graduate-level education, the association reversed (longer birth length associated with higher DCD probability). (2) Maternal employment status moderated the birth length–DCD relationship (unstandardized coefficient=0.6100, SE=0.3059, p<0.05). In unemployed mothers, lower birth length was associated with greater DCD probability; in employed mothers, no association was observed. (3) Annual household income moderated the relationship between birth weight for gestation age (BWGA) and DCD probability (unstandardized coefficient=−0.0043, SE=0.0022, p<0.05). In lower-income families, higher BWGA was associated with higher DCD probability; in medium- and higher-income families, a negative association was found. No significant moderation effects were found for head circumference or Apgar score at 5 minutes.
**Clinical Implications:** This study provides the first evidence that parental SES, particularly maternal education and employment status, moderates the relationship between birth health and DCD in preschool children. The findings suggest that shorter birth length may be a more important predictor of DCD than birth weight in certain socioeconomic contexts. Children of mothers with lower education or who are unemployed may be particularly vulnerable to the adverse effects of poor birth health on motor development. These results could help pediatricians identify children at greater risk for DCD based on both birth health and family socioeconomic characteristics. The study also highlights the importance of maternal factors in child neurodevelopment within the Asian cultural context. However, limitations include the cross-sectional design preventing causal inference, substantial missing data (up to 25%), small DCD sample size (n=23), and the study's inability to measure employment stability or other confounding factors such as maternal age and parental psychology. Future longitudinal studies with larger samples are needed to confirm these findings and explore the underlying mechanisms.