Morbidity and mortality of advanced gestational age: post-term or postmature.

A 6-year retrospective review of 53 post-term infants admitted to a neonatal intensive care unit (NICU) was undertaken to determine whether morbidity and mortality related to uteroplacental insufficiency were confined to infants with the postmaturity syndrome. Objective identification of infants with significant intrauterine growth retardation (IUGR) was done using the ponderal index (PI). All neonatal deaths occurred in large, appropriately grown infants and were associated with anoxic encephalopathy. Morbidity was equally distributed between normally grown and malnourished infants. Developmental outcome was similar in the 2 groups of infants. Neonatal complications and sequelae occurred in the absence of recognizable fetal malnutrition. Therefore, the post-term infant should be considered at risk, even if normally grown.