What indicates failure to thrive in infants?

Failure to thrive in infants is primarily identified by inadequate growth, which is often assessed using growth percentiles. When an infant’s weight falls below the third percentile for their age and sex, it signals that they are significantly underweight compared to their peers. This is a crucial indicator because it reflects not just a potential problem with nutrition, but also possible underlying health issues that may hinder proper growth and development.

Other factors, such as frequent crying episodes or delayed developmental milestones, can indicate various issues the infant may be facing, but they are not definitive markers of failure to thrive. Increased frequency of urination may raise concerns about hydration or potential urinary issues but does not directly correlate with growth and weight metrics necessary to diagnose failure to thrive. Thus, the weight percentile is the most direct and critical measure for assessing this condition in infants.