A child’s physical growth refers to the increase in height and weight and other body changes that occur as a child matures.
On an average, a baby is 50 cm at birth; growth velocity is 25 cm in the first year of life, 12.5 cm by the second year, six to seven cm in three to four years, and then five cm/year until onset of pubertal growth spurt. It is interesting to know that no child grows at a perfectly steady rate. A major growth spurt occurs at the time of puberty, between the ages eight to 13 years in girls, and 10 to 15 years in boys. Peak growth velocity during adolescence is nine to 11 cm/year for boys and seven to nine cm/year for girls. Puberty lasts for about two to three years. This growth spurt is associated with sexual development, which includes appearance of pubic and underarm hair, growth and development of sex organs, and in girls, the onset of menstruation.
The term ‘growth failure’ refers to a decline in the rate of linear growth (height velocity) that, if persistent, results in short stature, defines as height of more than 2.0 SD below the gender-specific population, meaning approximately equivalent to the third percentile.
The factors affecting growth are nutrition, socio-economic status, secular trend, genetic factors (stature of parents), race, sex chromosomes, hormonal factors, thyroid and sex hormones.
Monitoring of growth
- Are clothes getting shorter and shoe size changing?
- Where does the child stand in the class row?
- What is the height/weight record taken in doctor’s clinic?
Constitutional growth delay
Children who are small for their age, but who are growing at a normal rate, usually have a delayed ‘bone age’, which means that their skeletal maturation is younger than their age in years. Familial (or genetic) short stature implies that short parents tend to have short kids. Children with familial short stature have growth spurts and enter puberty at normal ages, but they will usually only reach a height similar to that of their parents. Variations of normal growth patterns are not growth disorders.
General systematic cause: Diseases of the kidneys, heart, gastrointestinal tract, lungs, bones, or other body system, may affect growth. An important cause is coeliac disease, which is sensitivity to a wheat element called gluten. Failure to thrive, which isn’t a specific growth disorder itself, but can be a sign of an underlying condition causing growth problems – is usually caused by inadequate nutrition or feeding problem, most common in kids younger than age three.
Hormonal cause: Endocrine diseases involve a deficiency or excess of hormones and can be responsible for growth failure during childhood and adolescence. Growth hormone deficiency is a disorder that involves the pituitary gland. A damaged pituitary gland may not produce enough hormones for normal growth. Hypothyroidism is a condition in which the thyroid gland fails to make enough thyroid hormone, which is essential for normal bone growth.
Genetic abnormalities: Noonan syndrome is a genetic growth disorders that occurs in girls. It is a syndrome in which there is a missing or abnormal ‘x’ chromosome in addition to short stature. Girls with Turner syndrome usually don’t undergo normal sexual development. In idiopathic short stature, everything is okay and all lab results and hormone levels are normal, but the child does not grow, and no cause can be found.
The treatment of a growth problem usually is not urgent, but earlier diagnosis and treatment can help some kids catch up with peers and increase their final height Treating systemic diseases of the kidney, lung or gut, if any, will improve height. For hormone problem, GH or thyroxine can be given according to deficiency; testosterone in males with delayed puberty, and eastradiol in girls. A gluten free diet is recommended for coeliac disease. Good diet, regular exercise, and regular follow up for monitoring growth pattern, are also essential.
What parents can do
Parents can ensure that their child grows and develops normally by following these tips:
- Enough rest
- Proper nutrition
- Adequate exercise