Objectives: To evaluate whether intrauterine growth restriction (IUGR) adds further neurodevelopmental risk to that posed by very preterm birth alone in terms of alterations in brain growth and poorer toddlerhood outcomes.
Study design: Participants were 314 VPT infants enrolled in the Evaluation of Preterm Imaging Study (e-Prime) who were subsequently followed up in toddlerhood. IUGR was identified postnatally from discharge records (n=49) and defined according to prenatal evaluation of growth restriction confirmed by birth weight < 10th centile for gestational age and/or alterations in foetal Doppler. Appropriate for gestational age (AGA; n=265) was defined as birth weight > 10th centile for gestational age at delivery. Infants underwent MRI at term-equivalent age (median=42 weeks); T2-weighted images were obtained for voxelwise grey matter volumes. Follow-up assessments were conducted at corrected median age of 22 months using the Bayley Scales of Infant and Toddler Development III (Bayley-III) and the Modified-Checklist for Autism in Toddlers (M-CHAT).
Results: IUGR VPT infants displayed a relative volumetric decrease in grey matter in limbic regions and a relative increase in fronto-insular, temporal-parietal and frontal areas compared with AGA VPT peers. At follow-up, IUGR VPT toddlers had significantly lower cognitive (ES = 0.42) and motor (ES = 0.41) scores and were more likely to have a positive M-CHAT screening for autism (OR = 2.12) compared with AGA VPT peers.
Conclusion: IUGR might confer a neurodevelopmental risk that is greater than that posed by VPT alone, in terms of both alterations in brain growth and poorer toddlerhood outcomes.