Failure to Thrive

Children who fail to grow properly have always existed. In earlier times when many children did not survive the first few years, small or sickly children were a fact of life. More recently, medicine has increasingly turned its attention to the unique problems of children, among them the problems of growth failure and most interestingly to the problem of malnutrition and growth failure in children without obvious organic illness. The case of so-called nonorganic failure to thrive, growth failure without apparent medical cause, is the main focus of this discussion.

The medical concept of "failure to thrive" in infants and young children dates back about a century.L. Emmett Holt's 1897 edition of Diseases of Infancy and Childhood included a discussion of a child who "ceased to thrive." Chapin correctly recognized in 1908 that growth failure was primarily caused by malnutrition, but that temporarily correcting caloric in-take and improving growth often proved futile after the child returned to her (often impoverished) environment. By 1933 the term "failure to thrive" formally entered the medical literature in the tenth edition of Holt's text.

Failure to thrive is not a discreet diagnosis or a single medical condition (such as chicken pox), but rather a sign of illness or abnormal function (as a rash or fever may be a sign of chicken pox virus infection). In infants and young children, the term "failure to thrive" is most broadly defined as physical growth that for whatever reason falls short of what is expected of a normal, healthy child. Statistical norms have been published for the growth patterns of normal children. Plotting a child's height, weight, and head circumference on such charts yields valuable diagnostic information. In children younger than age two, inadequate growth may be defined as falling below the third or fifth percentile for the age, where weight is less than 80 percent of the ideal weight for the age, or where weight crosses two major percentiles sequentially downward on a standardized growth chart.

The concept of failure to thrive, however, encompasses not just disturbances of the more obvious aspects of physical development but the more subtle aspects of psychosocial development in infancy and early childhood. "Thriving" is a concept that implies that a child not only grows physically in accordance with published norms for age and sex, but also exhibits the characteristics of normal progress of developmental milestones in all spheres—neurological, psychosocial, and emotional.

Early observations that an organic illness could not be found in many cases of failure to thrive led to the categorization of failure to thrive into the subclasses of organic and nonorganic causal factors. This classification ultimately proved too simplistic, both organic and environmental factors acting together may cause poor growth, but it served to sharpen thinking about the nonorganic causes.