THE SMALL-FOR-GESTATIONAL-AGE INFANT - ACCELERATED OR DELAYED PULMONARY MATURATION - INCREASED OR DECREASED SURVIVAL

Objective. Small for gestational age (SGA) neonates have been consider ed to have accelerated pulmonary maturation and thus a lower risk for respiratory distress syndrome (RDS) than appropriate for gestational a ge (AGA) neonates. This, however, has not been thoroughly examined. Th erefore, we compared SGA infants with AGA infants of the same gestatio nal age (GA) with respect to risk of RDS, respiratory failure, or deat h. Population. An indigent population born in a large county hospital. Methods. Multivariate analyses were performed controlling for GA alon e or for GA, race, sex, and congenital anomalies. Because the proper m ethod to identify SGA infants is unclear, we performed separate analys es using different GA estimates (obstetric or pediatric) and intrauter ine growth grids (hospital-specific grids or grids for a healthy, geog raphically-defined population). Results. SGA infants did not fare bett er than AGA infants in any analysis. SGA infants had significantly inc reased risk in some analyses of RDS and in almost all analyses of resp iratory failure or death. The risk associated with being SGA was gener ally comparable to that associated with male sex or White race. Conclu sion. The concept that intrauterine growth retardation accelerates lun g maturation and improves outcome is not supported in comparisons of S GA and AGA infants of the same GA, sex, and race. This widely accepted concept deserves critical re-evaluation.