Invasive Procedures in Preterm Children: Brain and Cognitive Development at School Age

Abstract

WHAT'S KNOWN ON THIS SUBJECT: Greater numbers of invasive procedures from birth to term-equivalent age, adjusted for clinical confounders, are associated with altered brain microstructure during neonatal care and poorer cognitive outcome at 18 months' corrected age in children born very preterm.WHAT THIS STUDY ADDS: Altered myelination at school age is associated with greater numbers of invasive procedures during hospitalization in very preterm children without severe brain injury or neurosensory impairment. Greater numbers of invasive procedures and altered brain microstructure interact to predict lower IQ. abstract BACKGROUND: Very preterm infants (born 24-32 weeks' gestation) undergo numerous invasive procedures during neonatal care. Repeated skin-breaking procedures in rodents cause neuronal cell death, and in human preterm neonates higher numbers of invasive procedures from birth to term-equivalent age are associated with abnormal brain development, even after controlling for other clinical risk factors. It is unknown whether higher numbers of invasive procedures are associated with long-term alterations in brain microstructure and cognitive outcome at school age in children born very preterm. METHODS:Fifty children born very preterm underwent MRI and cognitive testing at median age 7.6 years (interquartile range, 7.5-7.7). T 1 -and T 2 -weighted images were assessed for the severity of brain injury. Magnetic resonance diffusion tensor sequences were used to measure fractional anisotropy (FA), an index of white matter (WM) maturation, from 7 anatomically defined WM regions. Child cognition was assessed using the Wechsler Intelligence Scale for Children-IV. Multivariate modeling was used to examine relationships between invasive procedures, brain microstructure, and cognition, adjusting for clinical confounders (eg, infection, ventilation, brain injury). RESULTS:Greater numbers of invasive procedures were associated with lower FA values of the WM at age 7 years (P = .01). The interaction between the number of procedures and FA was associated with IQ (P = .02), such that greater numbers of invasive procedures and lower FA of the superior WM were related to lower IQ. CONCLUSIONS:Invasive procedures during neonatal care contribute to long-term abnormalities in WM microstructure and lower IQ. Pediatrics 2014;133:412-421