Growth Retardation And Short Stature

What is short stature?

Short stature is defined as the measured height below the lower limit of normal growth curve for a specific age and gender, or in other words, below the 3^rd percentile line. However, in more detailed definition, this is not accepted as the sole standard for short stature. Even if the height is not below the 3^rd percentile curve, the child should be evaluated regarding short stature if annual growth rate is below normal ranges.
Normal annual growth rate:

10-12 cm from 1 to 2 years of age
6-8 cm from 2 to 4 years of age
5-6 cm for prepubertal children older than 4.

Not all clinical picture of short stature is pathological. The reasons for short stature that are not considered as disease are as follows:

Familial short stature: Short stature can be observed in the child due to genetic factors if the mother or father or other relatives are short. Those children are healthy and their annual growth rates are within normal limits. However, their final adult heights are much likely to be immediately below or around the 3^rd percentile.
Constitutional delay in growth and puberty: This condition is common in boys. These children are healthy and they experience the signs of puberty and acceleration in growth rate later than their peers. There are usually other family members with same history. Although their heights are shorter than their peers after 3-4 years of age, their growth rate accelerates following the puberty and their final adult heights reach to normal limits.

Are there hormonal diseases causing short stature?

Yes, deficiencies of thyroid hormones (hypothyroidism) and growth hormone deficiency may result in slowed down growth and short stature.
When congenital deficiency of thyroid hormone is left untreated, it may cause slow growth and growth or mental retardation. Now, this condition is much rarer thanks to the neonatal screening program implemented in our country. Sometimes, if the clinical picture is not recognized and treatment delays as the deficiency of thyroid hormones develop late, growth rate may decrease, resulting in short stature. Should the growth rate of a child growing healthily up to a certain age slows down despite normal weight gain, acquired thyroid hormone deficiency requires a high-index suspicion.

Growth hormone deficiency can be congenital while it may also be an acquired condition. Developmental problems of the brain (pituitary gland or hypothalamus region), damage to the brain during or after birth, severe head trauma, tumors of this body part and radiotherapy to treat them may lead to growth hormone deficiency. Children with growth hormone deficiency have short stature; however, their body weights may be further high relative to their height and increased fat accumulation is remarkable especially in the belly region.

Can growth retardation that develops in intrauterine period result in short stature?

Even if the infants with intrauterine growth retardation are born at the end of a normal pregnancy period, their birth weights can be lower than normal ranges. While some of these infants can catch up their peers, who were born with normal body weight, in terms of height and body weight, some of them cannot and have short stature.

What are other causes of short stature?

In addition to the causes listed here, Turner syndrome is among the underlying causes of short stature in girls.
Moreover, diseases that are caused by abnormal development of bone-cartilage tissue, called skeletal dysplasia, also lead to short stature. Unlike the others, these diseases cause non-proportional short stature.
Nutritional disorders, severe deficiency in food and calorie intake and certain chronic diseases may also slow down the growth and cause short stature.

Some children may have short stature without any of these reasons – a condition called idiopathic short stature.

What are the examinations necessary for children with short stature?

First, medical history of both the child and the family should be investigated and current height and weight of the child should be marked on the growth curve. A physical examination which also addresses the adolescence is a must.

Laboratory and radiology tests

Necessary tests for diseases of kidney, stomach, intestines and heart that may lead to short stature
Thyroid gland disorders
Bone disorders
If there is a suspicion of growth hormone deficiency (if no other reason can be identified and annual growth rate is low and the bone age is significantly low), a stimulation test should be performed. Randomly analyzed growth hormone level is neither sufficient nor necessary for the diagnosis.
Various pharmaceutical agents (drugs such as clonidine, l-dopa and glucagon) are used for growth hormone stimulation tests. It is based on the measurement of growth hormone level in blood at 30-minute intervals after the drug is administered. Tests last for 90 to 150 minutes and the results are reported on the same day.
Evaluation of bone age: Wrist of the patient is X-rayed. It demonstrates the skeletal maturity. The growth potential of the child is determined according to skeletal maturity rather than the chronological age. Bone age is used to predict the adult height. Adult height prediction is a crucial parameter while making decisions on treatment. Determination of the bone age is associated with certain difficulties; the results can vary depending on the reviewer; in other words, it is a subjective test. BoneExpert – an artificial intelligence software preferred by pioneering pediatric endocrinology centers of Europe and the United States of America - is used at our hospital for evaluation of bone age. This program minimizes the margin of error arising out of the reviewer factor and it provides more objective results.

What is the method of growth hormone therapy and who are good candidates for this therapy?

Growth hormone treatment can be performed for children who have growth hormone deficiency manifested by above mentioned clinical and laboratory findings and children who have short stature due to Turner syndrome and intrauterine growth retardation. Social Security Institution (SGK) medication report can be issued at our hospital for children for whom growth hormone treatment is decided due to such diagnoses.
Growth hormone treatment is performed with subcutaneous injections on a daily basis.