Pounds per square inch. The pound per square inch or, more accurately, pound-force per square inch (symbol: lbf/in2; abbreviation: psi) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch:
small for gesÂ·taÂ·tionÂ·al age. Infant whose birth weight is below the tenth percentile for gestational age. small for gestational age. SGA. 1. Term describing an infant whose birth weight is at or below the 10th percentile, as correlated with the number of weeks in utero on the intrauterine growth chart.
A baby's birthweight is an important indicator of health. The average weight for full-term babies (born between 37 and 41 weeks gestation) is about 7 lbs (3.2 kg). In general, small babies and very large babies are more likely to have problems. Newborn babies may lose as much as 10% of their birthweight.