Neurophysiologic Maturation Index for Late Preterm Infants

Inclusion Criteria: * Gestational age of 340-346 weeks by Obstetric criteria (presence of a sure LMP or sonogram performed in the first trimester, or agreement between LMP and a sonogram performed between the first trimester and 20 weeks) * Admitted to a NICU of a participating institution * Post-natal age less than 96 hours Exclusion Criteria: * Major congenital anomaly/genetic anomaly * Growth restriction (birth weight \< 10%, Fenton growth curves) * Unsure obstetric dating (e.g., absence of a sure LMP without a sonogram, earliest sonogram performed after 20 weeks without a sure LMP, or discrepancy between LMP and sonogram) * Exposure to medications within the preceding 12 hrs which may affect CNS function (e.g., fentanyl, morphine, midazolam) * Neonatal seizures * Neonatal abstinence syndrome secondary to in-utero exposure to narcotics, methadone etc, or at high risk for development of abstinence * Hypoxia-ischemia defined as the combination of fetal acidemia (cord gas or blood gas within 1 hour of birth: pH ≤ 7.15 or BE ≥ -10mEq/L), need for resuscitation at birth (PPV ± chest compressions or medications), and evidence of encephalopathy (Stage 1, 2 or 3 Sarnat). Stage 1 encephalopathy will be defined based on the level of consciousness which is characterized by a hyper-alert state, apparent alertness, and irritability. In the absence of a cord or early post-natal blood gas, there must be a history of a perinatal event which may have compromised oxygenation or blood flow to the fetus. * Infants who are expected to be on mechanical (via an endotracheal tube) or high frequency ventilation for the first 96 hours after birth. * Inability to obtain the informed consent