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.
Appropriate for gestational age (AGA): the baby's weight is appropriate for the gestational age (weight between 10th and 90th percentile) Small for gestational age (SGA): a baby whose weight is less than expected for the gestational age (weight less than 10th percentile). Large for gestational age (LGA): a baby whose weight is more than expected for the gestational age (weight more than the 90th percentile).