Peripartum hypoxic risk and cognitive outcome: a study of term and preterm birth children at early school age.

The authors examined the relationships between gestational maturity, perinatal hypoxic risk, and intellectual outcome in early school-age children. The sample was composed of 48 children whose arterial pH obtained within 3 hr after delivery was between 7.3 (the lower end of the normal range) and 7.1 (the lower end of the moderately acidotic range). Gestational maturity did not account for a significant proportion of variance in outcome, whereas arterial pH was found to be significantly related to subsequent intellectual performance. The observed relationship between peripartum arterial pH and cognitive performance is especially noteworthy because the arterial pH range was restricted. The authors conclude that a "dose-response" relationship can be observed between arterial pH and intellectual outcome at early school age, even when the lower end of the acidotic range is truncated above the pH level that is thought to reflect severe asphyxia neonatorum.