Short or tall stature in children is commonly due to genetic heritage. Many countries have developed growth charts that indicate average heights and weights for their child populations, and these are routinely used in clinical practice. This is called "normalization" and it is a screening process based on heights and weights of most children within a specific population.
Normal growth rate, with consideration for genetic factors, is a symptom of good health. That is why it is very important to have a child's height and weight monitored regularly. A single height measurement will identify a child whose growth rate does not fit the average, but there is conflict as to whether this is the optimal way to identify a growth-related disorder. Repeated growth monitoring over time to identify growth velocity or speed of growth, more accurately depicts growth delay, short stature or poor weight gain.
Growth rates are usually very rapid in childhood and gradually slow until puberty when the final inherited outcome is reached.
Normal speed of growth is plotted on an isobar line indicating average child growth rates for a specific population. Using an isobar line can be challenging because the biological rate of growth for children is highly variable. Short bursts of growth interspersed with some arrests in height and weight are common. A certain amount of imprecision is routine, as children are living beings and not stationary objects with exact sizes. Preterm children have different growth rates than those born at term. When using a growth chart, it is important to use the child's actual age. If the child were born nine weeks early, the corrected age would be nine weeks less than the actual age since birth. Preterm boys are more likely to show slower growth rate than girls.
Infants are measured for height and weight at four-month intervals due to their rapid growth, and toddlers at six-month intervals. Average 12-month measurements are most accurate as children mature.
Growth that is persistently slower and crosses the isobar line is called "falling off the curve.' When this is indicated by several measurements, a pathological etiology may be suspected. Childhood conditions for short stature may be inflammatory bowel disease, cystic fibrosis, chronic renal failure, cardiac defects, diabetes mellitus, and cancer.
Addressing these conditions, or those relating to them, will be beneficial. Children with hypothyroidism will improve in energy and bowel function with proper treatment. If growth hormone deficiency is the cause of short stature, treatment will provide better bone density and muscle function. Improvements will often provide a more optimal growth pattern.
Genetic conditions related to short stature are sometimes identifiable during clinical examinations. Achondroplasia may be observed by noting shorter-than-normal arms and legs. This is called disproportionate short stature. Facial anomalies may indicate Williams or Down's syndromes. These syndromes are associated with short stature and poor weight gain.
There are a large number of clinical conditions relating to short stature and poor weight gain in children. Sometimes there is no identifiable cause of the condition. The normal growth rate is considered in this case. Healthy children grow at normal velocity, even though their stature may be shorter than average. Most children who remain consistently below the lower 2.5 percentile in height are within normal height for their genetics. This is termed familial short stature.
When growth velocities suddenly decline, prompt evaluation is indicated.
One out of ten children with heights below the 2.5 percentile have organic cause for delayed growth, and when growth falls well below that percentile, nearly 60% of children indicated organic cause for their short stature and poor weight gain.
Parents of shorter children, often boys, are concerned about the psychological implications of being very short within the taller populations. Tallness, combined with proper body weight, is considered a mark of beauty and success in many Western countries, and parents sometimes want medical treatment to spur growth. Care must be taken to ensure that the common phenomenon of normal short stature in children is not stigmatized by preconceived ideas of psychological dysfunction and failure to succeed.