How the Child Grows
The growth of the child consists of the set of bodily modifications that allow him to acquire, at the end of puberty, the anatomical, physiological and morphological features typical of adulthood.
Growth, therefore, does not represent a simple increase in body size, but also a progressive modification of body shapes and composition. In the growing child, for example, the relationships between the different skeletal segments are very different from those of an adult. In the newborn, in particular, the head represents about a quarter of the entire body length, while when skeletal maturation is completed this ratio drops to 1/7 or 1/8.
When born, the newborn is about 50 centimeters long, with an average weight of 3400 grams and a head circumference of 35 cm. Twenty "years later his body will have grown three and a half times in length and about 20 times in weight.
The duration of the growth is higher the later the sexual maturity is reached; obviously, the inverse discourse is also valid.
If we report the child's growth in a graph, we will realize that this occurs in different ways and rhythms depending on the body district studied.
Furthermore, if we consider a single parameter, such as statural growth, we note that it does not follow a linear and constant trend over time; in the specific case, the growth rate is maximum in the first months of life, decreases up to 2-3 years, stabilizes and after ten springs it undergoes a last, notable, increase.
Insights
Growth in Height
As anticipated, the baby's body grows rapidly in the first year of life, increasing, in terms of length, by 50% compared to neonatal values. To these first 25 cm will be added another 12-13 at the end of the 24th month.
From this moment on, the growth rate remains relatively constant (+ 5-6 cm / year). By the age of four, the child will have doubled his height (about 100 centimeters); he will only triple it 8 years later (150 centimeters).
In the prepubertal period, both males and females experience a clear statural jump (+ 8-12 cm / year for two or three years) which persists until sexual maturity is reached.
This rapid growth in stature is anticipated in females (it begins around 9 and a half years, peaks at 12 and ends around 14), while in boys it is a little more retarded (from 11-12 years up to 16, with peak around 14). For this reason, between the ages of 11 and 14, females outnumber males.
Around sixteen and a half years of age for females, and one year later for males, the boy will have reached about 98% of his final height and will complete it in the next 24 months.
The evaluation of the height of the parents allows to calculate, with simple mathematical operations, the so-called "target zone", that is to say the final height, or genetic target, foreseen in adulthood (see dedicated article). These are obviously average data, which may vary slightly from individual to individual.
In any case, the measurement of the height must be as accurate as possible since even a modest imprecision (eg 1-2 cm) can distort the interpretation of the data collected. For this reason it is good to remember that the evaluation of the growth of the child must always and in any case rely on the experience and expertise of the pediatrician.
Weight Growth
At birth, the weight appears quite variable (from 2.7 to 4.5 kg). In the following days, the newborn suffers a weight loss equal to about 5-10% of the initial weight, due to dehydration, sometimes insufficient food intake (colostrum) and dehydration. After this period, within about ten days, the newborn quickly regains the lost weight and proceeds with growth. Already at 4-5 months his body mass has doubled, while at the first candle it will even triple.
Similarly to what is described for the height, the weight growth rate decreases in the second year of life, flattening until puberty (+2.5 kg / year). The adolescent spurt (+6/7 kg per year) follows the statural increase, reflecting the skeletal growth and the muscular and adipose development induced by sex hormones.
Preventing childhood obesity, educating the child to a correct diet and regular physical exercise (compatibly with his preferences), is extremely important. This is because an obese child has a great chance of remaining so for the rest of his life, with all the physical and psychological consequences of this, certainly not happy, condition.
The baby's nutritional status is monitored by detecting the adipose folds, the thickness of which reflects the changes in the subcutaneous adipose tissue. As shown in the figure on the side, the development of fat mass follows a particular trend: it begins to increase around the 34th post-menstrual week, until it reaches a peak nine months after birth; therefore it tends to decrease up to 6 ° - 8 ° and, from this period onwards, it differs in the two sexes (both in quantity and in distribution).
Growth of body systems and growth percentiles "
