During the first months of life, the main factor influencing the height and growth of your child is nutrition. Therefore, in general and under normal conditions: “if during the first months of postnatal life a child eats well, it will grow well”. According to data from the Spanish Paediatrics Association, from 6-12 months of life, little by little, the hereditary component of growth becomes clear.
As a consequence of this, the relationship between the child’s size or later in life and the size of their parents is strong and their height increases greatly by the end of the third year of life. In addition, the progressive influence of genetics determines that between the 2nd and 4th year of life children begin a “growth turnaround” which they tend to maintain until the onset of puberty.
Therefore, children with genetics favourable to growth and a rapid maturation rhythm experience a period of acceleration that makes them reach a considerable height; while those who have a tendency because of their history to be shorter, have a slow maturation rhythm, and a lower growth.
Hormonal system
Paediatric articles state that even if the whole hormonal system intervenes, growth hormone is the main hormonal regulator of growth after birth, especially from 6 months of age.
During the foetal period, its role as growth regulator is almost non-existent, with a minimal impact at the end of gestation; so that children born without growth hormone have, in many cases, normal lengths and weights at birth. This situation is maintained during the first months of extra-uterine life.
In fact, growing up depends on multiple factors. Even if genetics and diet are very important, they are not everything. Internally, hormones have a lot of influence: In the prenatal period, insulin and other similar substances are of great importance; and once babies are born, the most determining hormone is the growth hormone, even if others do matter, such as sex-related hormones.
During the first years of life, thyroid hormones also have great power. This is especially true if there is a deficit of the same hormones, although growth hormone is fundamentally what determines the speed of growth in order to reach genetic potential.
In addition to nutrients, the factors which affect the production of this hormone are physical activity, hours of sleep, possible illnesses or stress.
The final height of a person will depend on what he eats, how he sleeps, how often he gets sick, what exercise he does, what activities he does and how he feels emotionally during his childhood. They also influence what the mother ate or smoked during pregnancy or how the placenta worked.
Stages of growth
Growth is not a periodic and gradual process; there are stages in which one grows a lot and others that not so much. During the prenatal period, growth is concentrated in the last trimester of pregnancy. Once born, growth is very rapid during the first and even the second year of life, then it slows down a little and speeds up again at puberty.
Taking the average, it is calculated that children grow around 25 centimetres in the first twelve months of life and another 10 during the second year, to follow at a rate of 4-6 centimetres per year until puberty, when growth increases to 8-10 centimetres per year over a period of two or three years. And once the puberty period is over, growth is reduced to 1 or 2 centimetres until the age of 20, which is when experts estimate that growth comes to an end.
