Neurologic Injury in Acidemic Term Infants

Objective To determine whether arterial umbilical cord gas (aUCG) pH, in anatomically normal-term infants, could select infants at risk for brain injury identified on magnetic resonance imaging (MRI). Study Design We performed a nested case-control within a prospective cohort of 8,580 women. Cases, with an aUCG pH < 7.10, were temporally, age, and sex matched to controls with an aUCG pH ≥ 7.20. Bi- and multivariable analyses compared the presence and severity of brain injury. Secondary analyses estimated whether elevated arterial base excess or lactate were associated with brain injury. Results Fifty-five cases were matched to 165 controls. There was no statistical difference in brain injury between the groups (adjusted odds ratio [aOR]: 1.8, 95% confidence interval [CI]: 0.7-4.4]). Base excess ≥ -8 mEq/L was not significantly associated with brain injury (p = 0.12). There was no increase in risk of injury based on elevation of arterial lactate ≥ 4 mmol L (p = 1.00). Cases were significantly more likely to have an abnormal score in several domains of the Dubowitz neurologic examination. Conclusion The aUCG acid-base parameters alone are not sufficient clinical markers to identify term infants that might benefit from MRI of the brain to identify injury.