Neonatal cerebral white matter injury in preterm infants is associated with culture positive infections and only rarely with metabolic acidosis

Objective

Neonatal cerebral white matter injury represents a major precursor for neurological impairment and cerebral palsy. Our objective was to identify risk factors associated with its development.

Study design

This retrospective case-control study of all births between 23 and 34 weeks gestation at a single university hospital between May 1994 and September 2001 identified 150 cases with white matter injury characterized by periventricular leukomalacia or ventricular dilatation from white matter atrophy that were chromosomally normal and did not have other congenital anomalies. Cases were matched to controls without brain injury by the next delivery within 7 days of their gestational age.

Results

There were small differences between controls and cases in gestational age (27.5 ± 2.7, 27.4 ± 2.6 weeks, P=.01) and birth weight (1053 ± 402, 966 ± 285 g, P=.002) that were statistically but not clinically significant. There was no difference in the percentage of controls and cases delivered by cesarean (45%, 49%, P=.64). There were no differences between controls and cases in umbilical arterial pH (7.27 ± 0.11, 7.25 ± 0.15, P=.19), base excess (−2.1 ± 2.7, −3.0 ± 4.1 mmol/L, P=.28), pH less than 7.0 (2/122 [2%], 3/107 [3%], P=1.0), or base excess less than −12 mmol/L (4/121 [3%], 6/106 [6%], P=.75). The cases had a significant increase in positive blood (19%, 29%, P=.036), cerebrospinal fluid (6%, 17%, P=.002), and tracheal (9%, 22%, P=.003) cultures during the neonatal period. Conditional logistic regression showed a significant association among multiple gestations (P=.02), intraventricular hemorrhage (P < .001), and positive tracheal cultures (P=.02) with cerebral white matter injury.

Conclusion

Culture-positive infection was associated with an increased risk of cerebral white matter injury in preterm neonates. Intrapartum hypoxia-ischemia as manifested by metabolic acidosis was rarely associated with white matter injury and was not different from the incidence in premature neonates without injury.

Key words: Periventricular leukomalacia, Neonatal metabolic acidosis, Neonatal infection