title: Invasive procedures in preterm children: brain and cognitive development at school age.
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). T1- and T2-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.
authors.affiliation: Departments of Neuroscience.
authors.forename: Jillian
authors.initials: J
authors.lastname: Vinall
authors.forename: Steven P
authors.initials: SP
authors.lastname: Miller
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Bjornson
authors.forename: Kevin P V
authors.initials: KP
authors.lastname: Fitzpatrick
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Poskitt
authors.forename: Rollin
authors.initials: R
authors.lastname: Brant
authors.forename: Anne R
authors.initials: AR
authors.lastname: Synnes
authors.forename: Ivan L
authors.initials: IL
authors.lastname: Cepeda
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Grunau
mesh_terms: D001921:Brain; D002648:Child; D002657:Child Development / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology* / Q000523:psychology; D007363:Intensive Care Units, Neonatal / Q000639:trends*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D011153:Population