The term Small for Gestational Age describes newborns who are too small for the appropriate gestational age. The English term has caught on and is abbreviated as SGA. Most SGA infants catch up with their growth later and reach normal height and weight.
What does small for gestational age stand for?
The term Small for Gestational Age, also abbreviated as SGA, has come to describe newborns who are too small and too light at birth. In these infants, the birth size or birth weight is on the low end of the normal statistical distribution. There are two different definitions. One definition sets length and weight at least two standard deviations below the mean. This corresponds to weight and length below the 3rd percentile. All physicians concerned with the long-term development of children favor this definition. In most cases, growth does not slow until the last third of pregnancy. In this case, the fetus no longer gains weight, although the size of the child at birth is still normal. In these cases, the term asymmetric retardation is used. If both weight and height are too small, symmetrical retardation is present. This definition is sufficient for statistics and is therefore not suitable for finding the cause of delayed development. There is also the term intrauterine growth retardation, which is also used synonymously with SGA. Strictly speaking, however, this definition covers only those children who show delayed growth due to a pathological cause. However, only a portion of all SGA children fall under this definition. The incidence of delayed growth during pregnancy is approximately five percent.
Causes
There are many causes of delayed growth. In most cases, it is simply a deviation within normal development. The growth is usually caught up after birth. Often it is not possible to speak of a pathological development. It is merely a statistical deviation. Nevertheless, there are of course causes for such statistical variations. These cannot be determined in individual cases. However, it is often due to the mother’s diet and lifestyle. Particularly in the case of smoking mothers, developmental delays in the fetuses are statistically more frequent. The nutritional status and the supply of nutrients to the fetus via the placenta also play a role. In some cases, infections and other diseases during pregnancy also have an impact on growth. Usually, the child’s growth and development normalize after birth. However, a much smaller percentage of children have delayed development due to a serious health disorder. These are often genetic defects that stunt growth and sometimes cause general physical dysplasia. Serious diseases of the pregnant mother, such as rubella, can also cause growth retardation in the fetus. Alcohol abuse during pregnancy also plays a major role. Last but not least, the use of medications must be checked.
Symptoms, complaints and signs
Already the English name “Small for Gestational Age” indicates the actual characteristic of SGA. At birth, affected infants are too small in terms of gestational age. They also have a birth weight that is too low compared with the statistical normal distribution. However, most children catch up in height and weight and later develop normally. For a few, however, there is a risk that the growth process will remain delayed. As a result, those affected in these cases suffer from short stature even in adulthood. This is particularly the case if there has been no significant growth spurt until the second year of life. After that, the growth deficit can usually no longer be made up. The slowdown in growth often begins in the last third of pregnancy. In about 30 percent of those affected, premature birth then occurs. Children with SGA often suffer from constant hypoglycemia and low blood calcium levels immediately after birth. When there is a lack of oxygen, more red blood cells are formed. This increases the viscosity of the blood and leads to circulatory problems.Only slightly more frequently than in normal-weight children is severe brain damage observed that leads to paralysis or causes movement disorders. Slightly more frequent are mild disorders of fine motor skills and movement coordination in affected schoolchildren. The risk of developing diabetes and cardiovascular disease in adulthood is also increased.
Diagnosis and disease progression
According to the SGA, an infant is too small after birth if he or she has a length of less than 46 centimeters and/or a weight of less than 2600 grams. This is two times the standard deviation below the mean values of 51 centimeters birth length and 3400 grams birth weight, respectively. Usually, this is not a problem because in more than 90 percent of cases, the infant catches up with normal development. In the remaining ten percent, short stature may occur. In the case of pathological disorders, the specific cause must be sought. Children with developmental delays are statistically at a higher risk of suffering from certain diseases in later years. They are particularly at risk of developing type 2 diabetes mellitus, obesity and metabolic syndrome. Already after the birth of SGA children, there is an increased insulin resistance, the risk of hypoglycemia and metabolic disorders. If growth does not intensify by the end of the second year of life, small stature remains. SGA is diagnosed by measuring body length and weight after birth while determining the age of maturity. Within two years, weight, length and head circumference are regularly documented. In individual cases, an underlying pathological cause must be investigated.
Complications
In general, Small for Gestational Age disease can have a very negative impact on the quality of life of the affected individual. The exact symptoms and complications of this condition depend greatly on the exact birth weight and birth size, so it is usually not possible to make a general prediction about the course of the condition. However, those affected by this disease suffer from short stature and furthermore from diabetes or obesity. These symptoms of the Small for Gestational Age disease can lead to bullying or teasing, especially in young people, and can also cause depression and other psychological problems. Furthermore, the metabolism of those affected is also often disturbed, resulting in insulin resistance. The treatment of Small for Gestational Age depends on the exact causes and can be carried out with the help of medication. Complications usually do not occur. However, the usual growth cannot be achieved even with the help of medications. Whether the disease leads to reduced life expectancy also cannot be predicted in general.
Treatment and therapy
Treatment of SGA is by adequate nutrition and sufficient supply of vitamins, minerals, and trace elements. This is paralleled by close monitoring of weight and body length development. If the child remains far below the mean by the end of the second year of life, other causes of growth retardation must be excluded by differential diagnosis. If the short stature persists, hormone therapy with growth hormone can be tried from the age of four. In many cases, the children then still reach a normal growth length within three years. However, growth hormone therapy should be continued without interruption until the final length is reached to avoid risking a growth deficit. In rare cases, however, no appreciable growth is achieved even with hormone treatment.
Prevention
The most important measure to prevent SGA in offspring is to maintain a healthy lifestyle especially during pregnancy. This includes consistently abstaining from smoking and alcohol. Furthermore, a balanced diet and plenty of exercise also have a positive effect on the child’s development.
Aftercare
Already the English designation “Small for Gestational Age” points to the actual characteristic of SGA. At birth, the affected children are too small in terms of gestational age. They also have a birth weight that is too low compared with the statistical normal distribution. However, most children catch up in height and weight and later develop normally.For a few, however, there is a risk that the growth process remains delayed. As a result, those affected in these cases suffer from short stature even in adulthood. This is particularly the case if no significant growth spurt has set in by the second year of life. After that, the growth deficit can usually no longer be made up. The slowdown in growth often begins in the last third of pregnancy. In about 30 percent of those affected, premature birth then occurs. Children with SGA often suffer from constant hypoglycemia and low blood calcium levels immediately after birth. When there is a lack of oxygen, more red blood cells are formed. This increases the viscosity of the blood and leads to circulatory problems. Only slightly more frequently than in normal-weight children, severe brain damage is observed, leading to paralysis or causing movement disorders. Slightly more frequent are mild disorders of fine motor skills and movement coordination in affected schoolchildren. The risk of developing diabetes and cardiovascular disease in adulthood is also increased.
Here’s what you can do yourself
In many children, initial short stature is followed by compensatory growth development. However, there is also a risk that patients will continue to be very small. In everyday life, parents should pay attention to a healthy diet to avoid deficiency symptoms and to reduce the risk of diabetes. In addition, regular check-ups with the doctor are necessary to assess the further development of height and weight. Even in later years, close medical check-ups are advisable to minimize the risk of any secondary diseases. At primary school age, certain neurological abnormalities may occur, which are manifested in movement disorders or impaired fine motor skills. Such symptoms require close examination in order to counteract worse disorders in time. In the family of those affected, there is sometimes an increased psychological burden. Above all, the patients themselves feel inferior due to their dwarfism. In such cases, a self-help group helps to cope better with the situation. In addition, it strengthens self-confidence and the dwarf patients do not feel alone with their problem. Everyday support often comes from relatives and friends. Furthermore, there are special furniture and other aids that make life easier for the persons of small stature.
