Estimation of gestational age by electrographic, clinical, and anatomic criteria

Current methods for estimating gestational age utilizing clinical parameters can be inaccurate in the very premature neonate. Neuropathologic studies have been used to verify these clinical estimates of gestational age. Estimates of maturity using neonatal electroencephalography have documented the evolution of regional and hemispheric electrical patterns at different gestational ages; however, electroencephalographic studies have not been compared with both anatomic brain studies and clinical examination criteria. Therefore, we studied 25 neonates with at least one electroencephalographic study prior to death and subsequent neuropathologic examination. Twenty-three estimates (92%) of gestational age in weeks, which were based on specific electrical patterns, agreed with sulcal-gyral development (e.g., the delineation of inferior frontal, superior temporal, calcarine sulci, and cytoarchitecture in various brain regions). Clinical (Ballard score) criteria and anatomic estimations of gestational age agreed in 18 of 24 patients (74%). Electroencephalographic estimates were significantly better than clinical estimates (p less than .05) for sick neonates who were less than or equal to 30 weeks gestational age.