Cerebral function in the growth-retarded fetus and neonate.

Abstract

Intrauterine growth retardation is associated with increased risks for permanent neurological disabilities. A series of studies was undertaken to elucidate whether fetal growth retardation causes a primary perturbation of brain function and development and whether an increased vulnerability for periods of oxygen lack exists. In two groups of neonates who were small for gestational age (SGA) evoked potentials were investigated. A high frequency of abnormal recordings were obtained in SGA babies. SGA babies had significantly longer latency periods for the primary evoked potentials than appropriately grown controls. In guinea pigs and rats growth retardation was induced by reducing the placental blood flow during late gestation. Growth retarded guinea pups demonstrated a considerable reduction of the ability to retain normal somatosensory evoked response during hypoxia compared to appropriately grown littermates. Growth retarded rat fetuses exhibited marked changes of the monoamine metabolism in the brain inasmuch as basal levels of serotonin and its main metabolite were low while an inappropriate acceleration of the serotonin synthesis rate took place during hypoxia. The tissue concentrations of aspartate were also significantly lower in growth retarded fetuses than normally grown littermates. Finally, lipid peroxidation was assessed. During adequate oxygenation no difference was observed when lipid peroxidation was assessed. During adequate oxygenation no difference was observed when lipid peroxidation in brain tissue of growth retarded and appropriately grown fetuses was compared but during mild-moderate hypoxia lipid peroxidation was significantly more intense in the growth retarded group.(ABSTRACT TRUNCATED AT 250 WORDS)