Influence of slight to moderate risk for birth hypoxia on acquisition of cognitive and language function in the preterm infant: A cross-sectional comparison with preterm-birth controls.

Abstract

The cognitive and language performance of a group of 26 preterm-birth preschool and early school-age children with slight to moderate risk for perinatal hypoxia was compared with the performance of a preterm-birth comparison group of 26 children. Despite the relatively small discrepancy in degree of risk, the cognitive performance of the 2 groups diverged significantly. When data for children with known perinatal arterial pH were combined, a curvilinear (quadratic) regression model provided the best fit. Increasing acidosis was linearly related to decreases in cognitive skills, with the bend in the curve occurring well within the normal range of pH values. Hence, in the preterm infant, even minor risk for birth hypoxia may result in discernible deviation from the expected developmental trajectory.Perinatal hypoxic-ischemic insult is thought to contribute not only to mortality and morbidity in the neonate (Gunn,

Perinatal pH and Neuropsychological Outcomes at Age 3 Years in Children Born Preterm: An Exploratory Study

“…These preliminary findings extend those of Raz and colleagues (Golightly et al, 2003;Stevens, Raz, & Sander, 1999) into two additional domains of cognitioncontrolled attention and emergent mathematics. Deficits in mathematics are found commonly in children born preterm, even in lower risk samples as was observed here (e.g., Espy et al, 2004;Taylor et al, 1995;.…”

“…As hypothesized, and similar to Raz and colleagues (Stevens et al, 1999;Hopkins-Golightly et al, 2003) in samples of school age children born preterm, pH was related to receptive vocabulary in preschool aged children at age 3 years. The consistency of these findings across albeit small samples of children born preterm, but who differ as a group in weights at birth, ages at evaluation, and in the type of verbal intellectual tasks administered, is notable.…”

“…The purpose here was not to understand the incidence of low initial pH in a representative cohort of children born preterm, rather to begin to characterize the potential impact of low initial pH in low risk children born preterm. For their data to be included in this report, arterial blood pH had to be measured within the first 3 h of life, and the pH value had to fall within the normal to subclinical range, consistent with Raz and colleagues procedure (Hopkins-Golightly et al, 2003;Stevens et al, 1999). In this hospital, initial pH was charted as a screening index for low risk infants, without the other blood values (e.g., PaCO2) for most infants.…”

“…Furthermore, the sample size of this preliminary is small, enhancing the chance of spurious findings, or minimally that the magnitude of the observed relations will not be as high when a larger, more diverse sample is studied. Certainly, the results from this study, taken together with those by Raz and colleagues (Hopkins-Golightly et al, 2003;Stevens et al, 1999), suggest that perinatal arterial blood pH warrants further study as a potential marker of subtle hypoxic-ischemic injury that likely affects cognitive outcome throughout childhood in those at risk due to preterm birth.…”

“…These findings are surprising, given that non-verbal skill deficits are a commonly observed sequalae in those born preterm. In a subsequent study (Hopkins-Golightly, Raz, & Sander, 2003), pH was related to both verbal and non-verbal abilities in a sample composed only of children born preterm. If performance on tests of intelligence is considered to represent an amalgam of neuropsychological abilities, the findings in the Raz and colleagues studies suggest that pH might be related to more specific outcomes in children born preterm.…”