Access Type

Open Access Dissertation

Date of Award

January 2024

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Psychology

First Advisor

Sarah Raz

Abstract

Hypoxia and ischemia are of the most common causes of acquired brain injury in preterm infants and often results in damage to the periventricular areas of the preterm brain. Several biochemical indices are commonly associated with hypoxic-ischemic injury, including blood pH, base deficit (BD), oxygen, and carbon dioxide (pCO2). The aim of this study was to examine the contribution of early biochemical indexes of hypoxic-ischemic risk, particularly blood gas measures and acid-base balance measures, to neuropsychological outcome in preterm preschool-age children. I was particularly interested in the link between measures obtained either at birth, immediately after birth, or within the first week of life and motor and language functioning at preschool age.Preterm children were assessed at 3-4 years of age, with 88 to 163 of the evaluated children qualifying for this investigation. Umbilical cord and neonatal blood-gas and acid-base measurements were collected retrospectively from medical records. The biochemical measures were the predictors of interest. Socioeconomic status, sex, sum of antenatal complications, and standardized birthweight served as covariates in linear mixed models. The dependent variables were performance scores on direct motor (gross and fine) and language (expressive and receptive) measures. Children with a history of moderate to severe intracranial pathology or cerebral palsy were excluded. The results showed that lower cord pH (p = .038) and higher cord pCO2 (p = .029) values were associated with lower gross motor, but not fine motor, skills in a sample of high-risk preschoolers. None of the associations between blood-gas or acid-base values and language outcomes were significant when an oral-motor subtest score was included as a covariate to exclude the motor component underpinning expressive language. In contrast, without this covariate, lower cord pH (p = .027) was associated with lower expressive language performance. These discrepant results suggest that the oromotor skills involved in expressive language may be the primary mechanism driving the observed relationship between early blood biochemical indices of risk and expressive language. Together, these findings suggest that severity of acidosis and hypercapnia are linearly associated with preschool-age gross motor and expressive language functioning in a preterm-born sample.

Download

Share

COinS