Failure to thrive: What it means and what to do

An infant, a toddler, a school-aged child, a teen: their main goal isn't just to live, but to thrive, to grow physically, mentally, and emotionally. But that doesn't always happen the way it should. And often, the first sign is slow weight gain, followed by decreased growth in body length or height, which can then be followed by decreasing progress in other body functions, including brain growth and mental abilities. And that process, is then labeled Failure to Thrive (FTT).

That's not the best name–because it was originally used decades ago when it was assumed that the cause was poor parenting. While that can occasionally still be the case, we know there's many causes for poor weight gain and growth. When the these result from another condition (a genetic defect or under-nutrition from poor absorption, for example), the problem is considered secondary or "organic." FTT is considered primary or "non-organic" when it occurs in an otherwise healthy child–and then we have to investigate further to look for food aversions, swallowing or sensory difficulties or unrecognized delays in development. 

Occasionally, what looks like FTT can actually be normal. As Dr. Jay Hochman points out on GutsandGrowth, 30% of full-term infants cross 1 weight and height percentile and  23% trend across 2 percentiles between birth and 2 years of age.  This normal decline usually occurs when normal or relatively small parents have a big baby, who gradually shifts his or her growth curves to match that of the parents.   

The main considerations then become to:

• Determine the extent of the decreases in weight gain, growth, and whether there's malnutrition
• Determine the cause
• Decide what needs to be done