Amniotic fluid neuron-specific enolase: a role in predicting neonatal neurologic injury?

Objective: To determine the relationship between amniotic fluid (AF) neuron-specific enolase and the development of neonatal intraventricular hemorrhage and periventricular leucomalacia.
Methods: Thirty-nine AF samples, obtained from women in preterm labor between 24 and 32 weeks' gestation, were analyzed for neuron-specific enolase. All women delivered preterm neonates who had neurosonograms on the 3rd and 7th days of life. The results of the neurosonograms were used to divide the study population first into normal and abnormal groups, then into normal, minor, and major brain lesion groups. The groups were compared for the median neuron-specific enolase, proportion with values of 6 microg/L or more, and other demographic characteristics.
Results: There were no differences between the groups' maternal and neonatal characteristics. However, the abnormal group had significantly higher median value of neuron-specific enolase than the normal group (9.5 microg/L and 2.0 microg/L, respectively; P < .001). The median neuron-specific enolase levels for the major, minor, and normal groups were 9.75 microg/L, 6.5 microg/L and 2.0 microg/L, respectively (P < .001). The optimum cutoff point, with a sensitivity of 89% and specificity of 100%, was 6 microg/L; 89% of the abnormals had values of 6 microg/L or more, compared with none of the normals (P < .001). The risk of developing intraventricular hemorrhage or periventricular leucomalacia was 11.5 times greater when AF neuron-specific enolase levels were 6 microg/L or more.
Conclusion: Amniotic fluid neuron-specific enolase is a useful marker of neonatal neurologic injury.