Gestational Age Newborns: A Review Review

In tro duc ti on The term small for gestational age (SGA) newborns has been used to describe a neonate whose weight and/or crown-heel length at birth is at least 2 standard deviations (SD) below the mean for the infant’s GA based on data derived from an appropriate reference population. Some publications define SGA as a birth weight or length below the 3rd, 5th, or 10th percentiles for GA (1,2,3,4). However,-2 SD, a cut-off value which is equivalent to the 2.3rd percentile, is likely to capture the majority of infants with impaired fetal growth. According to recent estimates, 4 115 590 infants were born in the United States in 2004. This means that, at 2.3 % of the population, there were approximately 95 000 infants born SGA. Intrauterine growth retardation (IUGR) and birth of SGA babies may be related to several factors. These include geneti