Aim: To assess the relationship between neonatal brain development and injury with early motor outcomes in infants with critical congenital heart disease (CCHD).Method: Neonatal brain magnetic resonance imaging was performed after open‐heart surgery with cardiopulmonary bypass. Cortical grey matter (CGM), unmyelinated white matter, and cerebellar volumes, as well as white matter motor tract fractional anisotropy and mean diffusivity were assessed. White matter injury (WMI) and arterial ischaemic stroke (AIS) with corticospinal tract (CST) involvement were scored. Associations with motor outcomes at 3, 9, and 18 months were corrected for repeated cardiac surgery.Results: Fifty‐one infants (31 males, 20 females) were included prospectively. Median age at neonatal surgery and postoperative brain magnetic resonance imaging was 7 days (interquartile range [IQR] 5–11d) and 15 days (IQR 12–21d) respectively. Smaller CGM and cerebellar volumes were associated with lower fine motor scores at 9 months (CGM regression coefficient=0.51, 95% confidence interval [CI]=0.15–0.86; cerebellum regression coefficient=3.08, 95% CI=1.07–5.09) and 18 months (cerebellum regression coefficient=2.08, 95% CI=0.47–5.12). The fractional anisotropy and mean diffusivity of white matter motor tracts were not related with motor scores. WMI was related to lower gross motor scores at 9 months (mean difference −0.8SD, 95% CI=−1.5 to −0.2). AIS with CST involvement increased the risk of gross motor problems and muscle tone abnormalities. Cerebral palsy (n=3) was preceded by severe ischaemic brain injury.Interpretation: Neonatal brain development and injury are associated with fewer favourable early motor outcomes in infants with CCHD.

Purpose: To systematically review evidence regarding the severity and prevalence of motor development in children with a critical congenital heart defect (CCHD) without underlying genetic anomalies. Summary of Key Points: Twelve percent of all included studies reported abnormal mean motor developmental scores, and 38% reported below average motor scores. Children with single-ventricle physiology, especially those with hypoplastic left heart syndrome, had the highest severity and prevalence of motor delay, particularly at 0 to 12 months. Most included studies did not differentiate between gross and fine motor development, yet gross motor development was more affected. Recommendations for Clinical Practice: We recommend clinicians differentiate between the type of heart defect, fine and gross motor development, and the presence of genetic anomalies. Furthermore, increased knowledge about severity and prevalence will enable clinicians to tailor their interventions to prevent motor development delays in CCHD.