Neonatal mortality and morbidity in extremely preterm small for gestational age infants: a population based study

Aim: To assess if growth restricted (small for gestational age, SGA) extremely preterm infants have excess neonatal mortality and morbidity. Methods: This was a cohort study of all infants born alive at 22-27 weeks' post menstrual age in Norway during 1999-2000. Outcomes were compared between those who were SGA, defined as a birth weight less than the fifth percentile for post menstrual age, and those who had weights at or above the fifth percentile. Results: Of 365 infants with a post menstrual age of <28 weeks, 31 (8%) were SGA. Among infants with a post menstrual age of <28 weeks, only chronic lung disease was associated with SGA status (OR 2.7, 95% CI 1.0 to 7.2). SGA infants with a post menstrual age of 2627 weeks had excess neonatal mortality (OR 3.8, 95% CI 1.3 to 11), chronic lung disease and a significantly higher mean number of days (age) before tolerating full enteral nutrition. SGA infants with a post menstrual age of 2225 weeks had an excess risk of necrotising enterocolitis. Conclusion: Extremely preterm SGA infants had excess neonatal mortality and morbidity in terms of necrotising enterocolitis and chronic lung disease,