Comparison of Phototherapy Results in Small-for-Gestational-Age and Appropriate-for-Gestational-Age Infants Weighing Less Than 2,000 Grams

The infant who is small for gestational age (SGA) is more mature at birth than similar weight infants who are appropriate for gestational age (AGA). Whether the SGA infant behaves as does the larger gestationally equivalent infant, or whether there are specific changes related to intrauterine growth retardation is a matter of some interest in the understanding of the special needs of these infants. The National Institute of Child Health and Human Development (NICHD) phototherapy study provided a large newborn population for whom birth weight, gestational age at birth, and, thereby, intrauterine growth were carefully assessed. Infants who weighed 2,000 g or more at birth were included in the study only when they became jaundiced, whereas infants who weighed less than 2,000 g at birth were routinely entered into the study. Consequently, this report will be limited to the lowbirth-weight population selected by birth weight. Too few SGA babies were present in the groups with greater birth weight to allow meaningful comparisons. PATIENT SELECTIQN All infants whose birth weight was less than 2,000 g were entered into the study at 24 ± 12 hours. Those excluded from the study were: (1) infants who died before 24 hours, (2) infants with serious congenital defects, and (3) infants whose mothers refused consent for study. The study population consisted of 922 infants surviving at 24 hours. Gestational age was calculated from the first day of the last menstrual period obtained from maternal history and also by the evaluation techniques of Dubowitz.25 Intrauterine growth was determined by plotting birth weight and gestational age on the Denver Intrauterine Growth Curves8; infants below the 10th percentile were considered SGA.