Normal patterns and variations of growth will assist clinicians in understanding subtle changes in body chemistry that may not manifest themselves for considerable periods of time (e.g., hypothyroidism, other endocrine problems). Discuss normal variations in growth.

Assessing a child’s growth pattern gives a picture of the child’s overall health. In fact, some suggest that growth be viewed as a vital sign. It is a sensitive indicator of general health. Abnormal growth may be the first manifestation of pathology. Despite this fact, a survey of primary care practices in the United States showed that 10% of pediatric practices and 40% of family practices did not measure children at well-child visits. It is often difficult to distinguish between normal and abnormal growth. Short stature may represent a normal variant or signify underlying disease.

In utero growth is influenced by nutrition, uterine size, and the metabolic environment. Insulin, insulinlike growth factor (IGF), and their binding proteins are important for fetal growth. Growth hormone (GH) and thyroid hormone do not have a role in growth in utero; however, they are major influences for normal postnatal growth. GH circulates free and bound and induces growth of chondrocytes at the growth plate. It also stimulates secretion of IGF-1, which mediates many of GH’s growth-promoting actions. During the postnatal period, there is rapid linear growth velocity that declines after birth. A child’s linear growth velocity averages 25, 12, and 8 cm/year during the first 3 postnatal years. From this time until the onset of puberty, linear growth occurs steadily at a rate of 4 to 7 cm annually; weight gain averages 2.5 kg annually. At puberty, sex hormones (testosterone and estrogen), coupled with GH, thyroid hormone, and nutrition, result in an accelerated rate of growth—the pubertal growth spurt. In girls, this
usually occurs during sexual maturity rating (SMR) 3 for breast; the growth spurt in boys typically occurs during SMR 4 in boys. Following puberty, growth ultimately ceases secondary to closure of the epiphyseal plates due to the effects of estrogen. Growth represents an intricate connection between genetics, hormones, nutrition, and environment. Physicians must accurately assess growth during every well-child visit and know when further evaluation is needed.

When evaluating a child with a possible growth problem, the accurate analysis of the growth curve is crucial. Four aspects of the growth curve should be evaluated: