Cerebral maturation in IUGR and appropriate for gestational age preterm babies

Intrauterine growth restriction (IUGR) is associated with increased risk of perinatal morbidity and mortality, as well as long-term neurological deficits. However, neurostructural correlations with observed developmental disabilities have not yet been established. Magnetic resonance imaging (MRI) could prove useful for assessing brain development in the early neonatal period. We evaluated cerebral lesions and morphological maturation by MRIs in 59 preterm neonates, in order to verify the hypothesis that IUGR interferes on human brain development. A total of 26 pregnancies were complicated by IUGR and 33 pregnancies delivered preterm at a comparable gestational age with appropriate for gestational age (AGA). Magnetic resonance examination was performed at the completion of 41 weeks' gestation. White matter disease studied with MR included periventricular cavitations and punctuate lesions characterized by increased signal on T1-weighted and decreased signal on T2-weighted images. Cerebral maturation was defined by the total maturation score, on the basis of 4 morphological parameters of cerebral maturation: myelination (M), cortical infolding (C), germinal matrix distribution (GM), and glial cell migration pattern (G). No difference in brain lesions and in the level of cerebral maturation was found between preterm AGA and IUGR neonates. However, myelination was significantly reduced in IUGR neonates with brain sparing compared to IUGR neonates with normal Doppler of middle cerebral artery. Our study could not demonstrate any major significant difference between preterm AGA and IUGR neonates in terms of lesion occurrence and cerebral maturation. We observed, however, a mild delay in myelination in IUGR with brain sparing in utero. The relevance of this finding needs to be investigated with long-term follow-up.