Extrauterine Growth Restriction Remains a Serious Problem in Prematurely Born Neonates

Abstract

Background. Poor growth is a common problem in premature neonates and may be associated with neurodevelopmental delay. Objective. To evaluate the incidence of extrauterine growth restriction (growth values ≤10th percentile of intrauterine growth expectation based on estimated postmenstrual age in premature (23–34 weeks’ estimated gestational age) neonates at the time they are discharged from the hospital. Design/Methods. Using a database formed from a computer-assisted tool that generates clinical progress notes and discharge summaries on neonatal intensive care unit admissions, we reviewed data on neonates discharged from 124 neonatal intensive care units between January 1, 1997, and December 31, 2000. We evaluated neonates who were born between 23 and 34 weeks’ estimated gestational age without congenital anomalies and who were cared for at and discharged from the same hospital. For each patient, we compared the discharge growth values to the expected values based on our intrauterine growth data and postmenstrual age on the day of discharge. We defined extrauterine growth restriction as having a measured growth value (weight, length or head circumference) that was ≤10th percentile of the predicted value. In each specific birth weight and estimated gestational age group, we counted the number of neonates ≤10th percentile for each growth parameter and calculated the percentage of patients who had values ≤10th percentile at discharge. Using logistic regression, we evaluated the factors associated with extrauterine growth restriction for weight, length, and head circumference. Results. Our sample included 24 371 premature neonates. Data on discharge weight, length, and head circumference was available on 23 970, 17 203, and 20 885 neonates, respectively. The incidence of extrauterine growth restriction was common (28%, 34%, and 16% for weight, length, and head circumference, respectively). For each growth parameter, the incidence of extrauterine growth restriction increased with decreasing estimated gestational age and birth weight. Factors independently associated with extrauterine growth restriction were male gender, need for assisted ventilation on day 1 of life, a history of necrotizing enterocolitis, need for respiratory support at 28 days of age, and exposure to steroids during the hospital course. Conclusions. Extrauterine growth restriction remains a serious problem in premature neonates especially for neonates who are small, immature, and critically ill.