Presented at the Neonatal Society 2010 Autumn Meeting.

Ball G¹, Boardman JP^1,4, Rueckert D³, Aljabar P³, Arichi T^1,2, Merchant N^1,2, Gousias IS¹, Edwards AD^1,2, Counsell SJ¹

¹ Institute of Clinical Sciences, Imperial College and MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK
² Division of Neonatology, Imperial College Healthcare NHS Trust, London, UK
³ Department of Computing, Imperial College London, London, UK
⁴ Simpson Centre for Reproductive Health, Royal Infirmary of Edinburgh, Edinburgh, UK

Background: Preterm birth is a leading cause of cognitive impairment in childhood, and is associated with a spectrum of structural brain abnormalities. Although global brain volume is often preserved, regional abnormalities in the cortex and subcortical grey matter, including the thalamus have been reported (1,2) but the nature and evolution of these altered developmental processes are poorly understood. Here, we investigate the relationship between increasing prematurity at birth and regional brain growth at term-equivalent age.

Methods: Approval for MRI of infants was granted by the local Research Ethics Committee. Using deformation-based morphometry we performed objective, whole-brain analysis of T1-weighted MRI acquired from 71 preterm infants at term-equivalent age (median gestational age at birth = 28+5 weeks (range: 23+4 to 35+2); median postmenstrual age (PMA) at scan = 41+5 (range: 38+1 to 44+4)). Linear regression was used to determine brain regions where volume was significantly associated with gestational age at birth.

Results: A linear relation was found between regional brain tissue volume and gestational age at birth (FDR-corrected p < 0.01) in the following brain regions: anterior temporal lobes, including the hippocampus; the orbitofrontal lobe; posterior cingulate cortex; the centrum semiovale and the deep grey matter, including the thalamus. In addition, this relation was observed in some parts of the midbrain and cerebellum. The figure shows all regions where age at birth was linearly related to tissue volume.

Conclusion: We show that by term-equivalent age, regional brain growth is gestation dependent with lower gestational age at birth predicting lower tissue volume in a number of specific brain regions.

Corresponding author: serena.counsell@imperial.ac.uk

References
1. Inder et al. Pediatrics 115, 286-294 (2005)
2. Boardman et al. Ann. Neurol. 62, 185-192 (2007).