Severity of perinatal illness and cerebral cortical growth in preterm infants

Aim: We have shown previously that the degree of prematurity affects cortical surface area growth. We now addressed the question whether cortical surface area growth after preterm birth is predicted by the severity of peri- and postnatal illness. Methods: Cortical surface area was measured in 269 images from 111 infants born between 23 and 29 weeks and imaged at 23 to 48 weeks gestational age (GA). The severity of perinatal illness was assessed using the clinical risk index for babies score (CRIB I) and the severity of ongoing illness by the presence of chronic lung disease (CLD). The effects on cortical growth were modelled using generalized least-square regression for random effects with Bonferroni correction. To explore the results further we examined CRIB II, C-reactive protein (CRP) on the second day after birth, and time taken to achieve full enteral feeding. Results: Cortical surface area grew by 12.4% per week. Reduced cortical growth was predicted by adverse CRIB I (–0.15% per week per unit) and development of CLD (–1.18% per week). Secondary analysis showed that growth was related to adverse CRIB II (–0.36% per week per unit) and increasing CRP (–0.03% per week per mMol), but not by the time taken to achieve full enteral feeding. Conclusion: After very premature birth illness severity predicts reduced cortical growth.