A critical birth weight and other determinants of survival for infants with severe intrauterine growth restriction

Our objective was to assess the perinatal management and neonatal outcomes of premature, severely intrauterine growth-restricted (IUGR) neonates. A cohort of neonates < 1000 grams, less than or equal to first percentile for weight, and < 37 weeks' gestation was identified and matched 2:1 to two control sets of premature, appropriate-for-gestational age (AGA) infants-one with similar gestational age (AGA-GN group) and the other with similar birth weight (AGA-BW group) to determine the effect of IUGR on the outcome of the premature infant. The IUGR group was then examined in detail for descriptive statistics. Data were analyzed by t-tests and Chi-square analyses where appropriate. The IUGR infants had worse outcomes than AGA-GA controls but had somewhat better results than the AGA-BW controls. In the IUGR group, a birth weight less than 550 grams was significantly associated with neonatal death (p < 0.001). However, increasing gestational age was not associated with neonatal survival (p = 0.661) if birthweight remained below 550 grams. Classical cesarean delivery was associated with neonatal death (p = 0.003). Neonatal variables associated with poor outcome included patent ductus arteriosus (p = 0.034), feeding intolerance (p = 0.046), and failure to thrive (p = 0.05). Overall, neonatal survival was 73%. Of the surviving neonates, 69% had evidence of neurodevelopmental delay when tested at 6 and 12 months. Premature, growth-restricted neonates with birth weights of < 550 grams versus those of > 550 grams have dismal outcomes despite a gestational age that is compatible with survival.