- The development of a child proceeds almost continuously, but this continuity is progressive in nature and there is an indirect dependence on biological age. In other words, the younger the child, the more intense the processes of synthesis of new organs and tissues and, as a consequence, the child’s development . In children, there are two sharp developmental leaps: one year of age and puberty. In the intervals between them, the child’s weight, of course, increases, but not so intensely and completely stops by the age of 18-20. Let’s consider the main reasons for sudden jumps in the development of a child.
The relationship between chronological and biological age
Biological age is the unity of development of the tissues of the child’s body, which depend on the unique characteristics of the child.
Chronological age is a period that shows how long a child has lived since birth. This age can be easily determined using documents. Chronological and biological ages often do not coincide with each other. This is more typical for girls, who are characterized by faster biological maturation. As a result, girls' weight and height exceed those of boys.
Features of the first year of life
In terms of increasing the main indicators of physical development, the first year of a newborn is considered the most active. According to experts, during the first year of life, the “length” of a baby increases by 20-25 cm, and the weight doubles by 6 months and triples when it reaches one year.
If we analyze this issue in more detail, it is worth noting that in the first months of life, the baby gains the maximum number of kilograms, often this figure easily reaches 1-1.8 kg. In the future, when he becomes more active and mobile, the number of kilograms gained is significantly reduced. So, by 11-12 months the baby can gain 100-500 g, but at the same time, it is not considered a deviation if he does not gain anything.
As for growth, there are no clear trends, and everything depends on the conditions in which the child is located and his nutrition. The absolute norm would be if the baby grows by 5 cm in one month, and only by 1 cm in the next. However, to be sure that the baby is developing well, do not skip monthly visits to the pediatrician.
Heterochrony or heterogeneity in the development of organs and systems of the body
At different ages of the child, body weight will increase depending on which part of the body receives the greatest development. So, at the age of 10-12 years, the child will intensively develop lymphoid tissue, which practically did not work in previous years. And after 12 years, the genital organs and the formation of reproductive function begin to develop. In girls this is clearly expressed. Because under the influence of female sex hormones, fat is deposited in the body and body weight increases. In boys, under the influence of testosterone, muscle mass will increase, and as a result, overall weight will increase.
Indicators of physical development of girls and boys under one year of age
The height and weight of a child up to one year are the most important parameters for determining the normal development of the child. The nurse or doctor weighs the child monthly, measures his height, chest and head circumference, and records these figures in the medical record. What factors are taken into account?
- Maternal nutrition after conception.
- Gender of the child.
- Weight and height of the child at birth.
- Nutrition - height and weight directly depend on the daily intake of protein, carbohydrates, fats and calcium, vitamins and other microelements.
- Previous illnesses: ARVI, intestinal infections, severe dehydration, teeth thinning and loss of appetite.
- Genetics - the presence of disorders, congenital pathologies, chromosomal diseases.
- Social conditions in which the child is raised. Problems in the family environment directly affect the growth and development of the child. They lead to a delay or even arrest of development, and the genetic material that was passed on from parents to child does not reach its full potential. Children who develop in an environment filled with love, joy, peace and trust develop more harmonious and healthy bodies;
- Sleep - a child grows most rapidly during sleep. Systemic lack of sleep actually affects the development of the baby.
If a child is born prematurely or underweight, the weight and height of such a baby will differ from those of children born from 38 to 42 weeks of pregnancy and normal weight.
Gender differences
Gender differences will also influence the child's level of development. Boys will be ahead of girls in height and weight before puberty. But from the beginning of puberty (about 11 years old in girls), this ratio changes sharply: girls have higher indicators than their peers in terms of their weight, body length, and chest circumference. At the same time, different levels of development of functional systems are recorded, especially respiratory, muscular and cardiovascular. Upon reaching puberty, boys again begin to outstrip girls according to these data.
Weight and height of a child from 8 to 17 years old, table
Height and weight of the average child from 8 years old and a teenager up to 17 years old.
| Age | Boys | Girls | ||
| Height, cm | Weight, kg | Height, cm | Weight, kg | |
| 8 years | 122,1 — 130,8 | 23,3 — 28,3 | 123,0 — 131,0 | 23,0 — 28,5 |
| 9 years | 125,6 — 136,3 | 25,6 — 31,5 | 128,4 — 137,0 | 25,5 — 32,0 |
| 10 years | 133,0 — 142,0 | 28,2 — 35,1 | 134,3 — 142,9 | 27,7 — 34,9 |
| 11 years | 138,5 — 148,3 | 31,0 — 39,9 | 140,2 — 148,8 | 30,7 — 38,9 |
| 12 years | 143,6 — 154,5 | 34,4 — 45,1 | 145,9 — 154,2 | 36,0 — 45,4 |
| 13 years | 149,8 — 160,6 | 38,0 — 50,6 | 151,8 — 159,8 | 43,0 — 52,5 |
| 14 years | 156,2 — 167,7 | 42,8 — 56,6 | 155,4 — 163,6 | 48,2 — 58,0 |
| 15 years | 162,5 — 173,5 | 48,3 — 62,8 | 157,2 — 166,0 | 50,6 — 60,4 |
| 16 years | 166,8 — 177,8 | 54,0 — 69,6 | 158,0 — 166,8 | 51,8 — 61,3 |
| 17 years | 171,6 — 181,6 | 59,8 — 74,0 | 158,6 — 169,2 | 52,9 — 61,9 |
The role of heredity
The growth of a child is a program that is included in the DNA. The genetic program ensures the life cycle of the child, controls the change in periods of development in appropriate conditions of nutrition and upbringing of the child.
The genetic program plays a very important role in the child's adaptation. Thus, under the influence of the external environment (starvation, infection), a profound restructuring of the body’s metabolic processes occurs, which will help the child survive.
The hereditary apparatus will help produce the necessary hormones, biologically active substances, everything that will help the child improve his immune reserve and resist the disease.
Deviations from the norm
All standards established by the Ministry of Health are only average indicators. Accordingly, if you see that your child is cheerful, active, eats well and plays, but is 1.5 kg less than the stated norm, then there is no reason to worry. However, if you notice that the increase in height over the year is less than 4 cm and less than 3 kg in weight, then this is a reason to consult a pediatrician.
The pediatrician will be able to examine the baby and suggest which specialist can help you in resolving this issue: a gastroenterologist, geneticist, neurologist or endocrinologist. Depending on the results of the examination, your baby may be prescribed a course of additional vitamins, changes in diet and lifestyle. In more serious cases, a course of treatment may be prescribed, which includes taking hormonal medications.
Overweight in a child under one year old: why, what to do
Problems usually arise with artificial nutrition. In most cases there are three reasons:
- Baby food is not properly selected, does not meet needs, or is not used correctly by parents. for example, the mother thinks that the diluted formula does not taste at all, and to correct this, she adds more mixture than indicated. The child gets extra calories and gains weight with all the health consequences.
- Overfeeding - if you act on the principle “the child will not eat more than he needs” - then you are mistaken. In fact, the baby obeys his sucking reflex and absorbs extra calories.
- A genetically determined abnormality or nervous system control over the gastrointestinal tract is not developed for some reason.
The specific cause must be determined by a pediatrician.
You should also take into account the following nuances when feeding infants: if regular food does not cause a rash and changes in stool in the child, parents often prematurely begin to give him food from their table in addition to formula.
As a result, some 4-month-old babies are already eating half a banana, others are scratching their gums on a cookie, thereby taking in additional food several times a day. This can result in excess weight, and sometimes in underweight (if nutrition is insufficient).
The problem is not weight, but...
Most of the problems are related to overprotective parents and a number of psychological problems inherent in our culture.
Many grandmothers and mothers believe that a child should be well-fed. Fatness is an indicator of health. They do not take into account that physical indicators are individual, they still tend to compare their child with other children. In our culture, we respect physical strength and people in the body. It is believed that someone else’s child, who is a few grams fatter or a few centimeters taller, is more developed. The mother is probably on a diet, but she feeds the child excessively so that it is no worse than others. And grandmothers who suffered from hunger and poverty want to “provide” the future generation with red cheeks and plump legs.
Height to weight ratio in children
As we have already indicated, height and weight, considered separately, are not informative enough to determine the normal development of a child. Pediatricians are interested in their ratio - the correspondence of a certain height to a certain weight. If they are within normal limits, it means that the child is developing harmoniously; deviations from the norm indicate disorders that may be pathological.
Body mass index for children Quetelet
This is the formula for calculating your height/weight ratio. It doesn't take age into account. This is just the weight in grams divided by the height in centimeters. The Belgian statistician and mathematician Adolphe Quetelet developed an index that indicates the harmonious development of newborns:
Birth weight: height at birth = 60 - 70 The number to the right of the equation shows the index. In the range from 60 to 70 it is harmonious and healthy, and anomalies are pathological.
Example : a child was born with a weight of 3.350 kg and a height of 52 cm - this is normal. But with a height of 56 cm, its mass is too low.
3350 g: 52 cm = 64.4 - normal 3350 g: 56 cm = 59.8 - below normal, the child’s height is below normal 3350 g: 47 cm = 71.2 - above normal, the child is taller than normal
Using this formula, you can always calculate how your child is developing (within what limits). It works during the next months after birth, without taking into account age itself.
And for older children, a Quetelet index below 60 means underweight due to intrauterine malnutrition. For what reason - should be clarified.
The Quetelet index and the calculation formula are valid only for children born during term birth . For premature infants, there are other indices and formulas.
Forecast indices
Other formulas allow you to predict the final growth of a child - they take into account the genetic basis:
Hawker's formula
Boy's height = (father's height + mother's height): 2 + 6.4 cm Girl's height = (father's height + mother's height): 2 - 6.4 cm
Formula for Frame
Boy's height = (Father's Height + Mother's Height X 1.08): 2 Girl's height = (Father's Height x 0.923 + Mother's Height): 2
Smirnov/Gorbunov formula
Boy's height = (father's height + mother's height + 12.5): 2 Girl's height = (father's height + mother's height - 12.5): 2
With this formula, the resulting height changes by +/- 8 cm.
Checking the parameters using specific examples showed that the third formula is closest to reality.
The child’s height/weight is not normal: why, what to do
The real sign of a problem is not a specific indicator that does not correspond to the table, but a general deterioration in the child’s condition + weight problems. Weight loss in combination with any of the following is a worthy cause for concern:
- The child suffers from severe dermatitis;
- Its development is periodically disrupted - it becomes chaotic, stops;
- The child periodically suffers from complications;
- He gets excited easily or, on the contrary, is too calm.
In the above cases, being underweight is just one symptom of the problem.
When the baby is alert and healthy, deviations from 75% to 125% from the data in the table are not a cause for concern. Variation comes from factors such as genes, food, lifestyle. To make sure your baby is developing properly, check the head circumference as well as the chest circumference. An alarming sign of going beyond the norm is when some indicator reaches an extreme - plus or minus.
Growth disorders in children - why?
Suspicion falls on hormones or pathologies of internal organs, if there are no adverse external effects - for example, injuries, if the child receives proper care and proper nutrition.
- Problems may be associated with endocrine disorders.
- Skeletal dysplasia and chromosomal diseases accompanied by short stature.
- Pathologies of the kidneys, liver and gastrointestinal tract.
- Indirectly - liver problems.
- In addition, growth disorders in children include some hereditary forms of pathology, for example, familial short stature.
