RT Book, Section A1 Duryea, Teresa A1 Motil, Kathleen J. A2 Kline, Mark W. SR Print(0) ID 1182917227 T1 Poor Weight Gain T2 Rudolph's Pediatrics, 23e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259588594 LK accesspediatrics.mhmedical.com/content.aspx?aid=1182917227 RD 2022/08/17 AB Poor weight gain is the finding of weight loss or a deceleration in the rate of weight gain. Failure to thrive describes the condition of infants and toddlers under age 2 years who have an abnormally low weight relative to their stature for their age and sex. With prolonged and/or severe malnutrition, linear growth and head circumference can be secondarily affected. The term failure to thrive is not a singular disorder; rather, poor growth is a sign of an underlying problem that leads to insufficient usable nutrition. A wide variety of medical and psychosocial factors can contribute to poor weight gain.