Growth Problems in Children

How normal growth works

Children grow fastest in infancy, gaining about 10 inches (25 cm) in the first year. Growth then slows to about 2 to 3 inches (5 to 7.5 cm) a year from age 3 until puberty, when a growth spurt adds several inches a year. Growth stops when the growth plates in the long bones close, usually by about 15 in girls and 17 in boys.

Growth depends on genes, nutrition, sleep, general health and hormones, especially growth hormone, thyroid hormone and, at puberty, sex hormones.

How growth problems are spotted

Doctors plot height, weight and, for babies, head size on growth charts at checkups. Children usually follow a percentile line. Warning signs are:

• height below the 3rd percentile (or above the 97th)
• crossing downward through two major percentile lines
• slow growth velocity measured over 6 to 12 months
• height far from the target height predicted from the parents' heights

A single measurement means little; the trend over time is what matters.

Causes of growth problems

Normal variants (most common)

• Familial short stature: short parents, a short child growing at a normal rate along a low percentile, normal bone age and puberty on time. Adult height is short but normal for the family.
• Constitutional growth delay: "late bloomers" who grow slowly, start puberty late and have a delayed bone age, often with a parent who was also a late developer. They catch up and reach normal adult height.

Nutrition and chronic illness

• Undernutrition or inadequate calories, including restrictive eating and eating disorders in teenagers.
• Celiac disease: sometimes poor growth is the only sign.
• Crohn's disease and other inflammatory bowel disease.
• Chronic kidney disease, heart disease, cystic fibrosis and poorly controlled asthma.
• Long-term high-dose steroid medicines.
• Psychosocial deprivation: severe neglect or stress can suppress growth hormone.

In babies, poor weight gain is called failure to thrive.

Hormone causes

• Underactive thyroid: growth slows markedly, with weight gain, tiredness and constipation.
• Growth hormone deficiency: slow growth, a chubby, younger appearance and delayed bone age. It may be present from birth or caused by a pituitary tumor, injury or radiotherapy.
• Cushing syndrome: weight gain with slow growth, unlike simple obesity where children are usually tall.
• Early puberty: precocious puberty causes a spurt in early childhood but early closure of growth plates and short adult height.

Genetic and skeletal conditions

• Turner syndrome in girls: short stature, delayed puberty, sometimes a webbed neck or heart problems. Any girl with unexplained short stature should be tested.
• Noonan syndrome, Prader-Willi syndrome, Down syndrome and Silver-Russell syndrome.
• SHOX gene deficiency.
• Skeletal dysplasias such as achondroplasia, with short limbs compared with the trunk.
• Being born small for gestational age, where about 1 in 10 children do not catch up by age 2 to 4.

Tall stature and overgrowth

Excessive growth is less common. Causes include tall parents, early puberty, Marfan syndrome, Klinefelter syndrome and, rarely, excess growth hormone from a pituitary tumor.

How doctors investigate

1. History: birth weight, feeding, diet, illnesses, medicines, development, puberty and parents' heights and puberty timing.
2. Examination: accurate height with a stadiometer, body proportions, signs of puberty, features of syndromes and signs of chronic disease.
3. Bone age X-ray of the left hand and wrist, which shows how much growth remains.
4. Blood and urine tests: blood count, kidney and liver function, celiac antibodies, thyroid tests, inflammatory markers, IGF-1 (a marker of growth hormone), and a karyotype in girls.
5. Growth hormone stimulation tests and a pituitary MRI if growth hormone deficiency is suspected.

Treatment

Treatment depends on the cause:

• Normal variants: reassurance and monitoring. Short courses of sex hormones are sometimes used for teenagers with very delayed puberty.
• Nutrition and chronic disease: better nutrition, a gluten-free diet for celiac disease, and controlling Crohn's or kidney disease often produce catch-up growth.
• Hypothyroidism: daily thyroid hormone tablets.
• Growth hormone injections: for growth hormone deficiency and some other conditions such as Turner syndrome, Prader-Willi syndrome, SHOX deficiency, chronic kidney disease and children born small who have not caught up. Earlier treatment gives better results.
• Precocious puberty: medicines to pause puberty.

Frequently asked questions

When should I worry about my child's growth?

Talk to your child's doctor if they are much shorter than classmates and their parents would predict, are falling across lines on the growth chart, grow less than about 2 inches a year after age 3, or have other symptoms such as tiredness, diarrhea, headaches or delayed puberty.

What is the most common cause of short stature in children?

The most common causes are familial short stature, where a child inherits short height from parents, and constitutional growth delay, where a child develops later than peers. Both are normal variations. These children are healthy and grow at a normal rate.

Can a child catch up in height?

Yes, often. Late bloomers catch up after a delayed puberty. Children whose growth was slowed by poor nutrition, celiac disease, hypothyroidism or other illnesses usually show catch-up growth once the cause is treated. Growth hormone treatment can improve height when it is lacking.

Does growth hormone treatment work?

For children with growth hormone deficiency, daily or weekly injections typically increase growth rate markedly and improve adult height. It also helps in certain other conditions. It is given by injection under the skin and needs regular monitoring by a pediatric endocrinologist.