Failure to Thrive: A Consequence of Undernutrition

Sheila Gahagan, MD, MPH 1. *Clinical Professor, Department of Pediatrics and Communicable Diseases; Assistant Research Scientist, Center for Human Growth & Development, University of Michigan, Ann Arbor, Mich After completing this article, readers should be able to: 1. Recognize three common presentations in the physician’s office of failure to thrive. 2. Identify three principal mechanisms that lead to a mismatch between caloric intake and caloric expenditure. 3. Understand the complex interaction between psychosocial and biomedical risks that may lead to failure to thrive. 4. Review the diagnostic approach based on three different growth presentations. 5. Discuss the role of the physician in identifying psychosocial factors in failure to thrive and in referring families to mental health professionals. Failure to thrive (FTT) is not a disease, but a sign that is better thought of as a final common pathway of many medical, psychosocial, and environmental processes that lead to poor growth in a young child. Although FTT once was conceptualized as either organic or nonorganic, it now is understood to be the result of interaction between the environment and the child’s health, development, and behavior. The evaluation of a young infant who is growing slowly, or not at all, is truly the ultimate test of the pediatrician’s ability to evaluate simultaneously biomedical and psychosocial information obtained from the medical history and the physical examination. The stakes are high during the diagnostic phase because the child could have a life-threatening disease or be in a life-threatening psychosocial environment. Fortunately, these dire scenarios are exceedingly rare. Most cases of FTT are due to inadequate nutrition that results from biologic and environmental factors that intersect in such a way as to preclude adequate nourishment of the child. It is essential to take a developmental approach to poor growth because the causes of this condition change with development. Two case histories are presented to illustrate examples of medical and psychosocial conditions leading to inadequate growth. Management must be tailored to the child, taking into account medical, psychological, family …