What is head circunference?

What Does head circunference Mean

The idea of perimeter refers to the outline of a figure or a surface . Cephalic , meanwhile, is that linked to the head (the upper region of the body, where the brain is located).

As can be seen from these definitions, the concept of head circumference refers to the contour of the head . It is a measurement that is made in children , considering the distance that extends from the area above the ears and from the eyebrows to the back.
The process is carried out with a tape measure . The tape should be located over the ears and eyebrows and surround the entire contour of the head.

By measuring head circumference, the pediatrician can analyze the infant's development . Each new data is compared with the previous measurements of the patient's head circumference and with the values ​​considered normal according to the age and sex of the child, with periods that are counted in weeks or months.
The measurement of the head circumference, in short, is part of the routine controls of a child. The doctor expects some growth of the head which, if not reflected in these checks, may reveal a possible disorder.
The head circumference must grow especially between the first two and three years of life, since at that time the neuronal connectivity increases more than ever. Let's look at the specific values ​​that doctors expect to find after measurements of children up to one year: the first three months, the head circumference is expected to grow 2 centimeters per month; between the third and sixth month, 1 centimeter per month; between six months and a year, it should grow 0.5 centimeter per month.
With regard to the weight of the brain, in a newborn baby it should be around 350 grams, while in an adult of about 20 years, 1350 grams. As mentioned in the previous paragraph, throughout the first three years of life, the growth of this part of the body occurs with a special emphasis: at six months, for example, it reaches 50 percent of its total weight ; per year, 60 percent; at eighteen months, 75 percent.
A smaller-than-normal head, for example, could reflect slow growth or microcephaly . On the contrary, an overly large head is possible that it is a sign of hydrocephalus .
With regard to microcephaly, we can say that most of the cases are registered because the brain does not grow at a rate considered normal, since this anomaly directly affects the development of the skull, something that occurs during pregnancy and lactation. Some of the most common causes are: uncontrolled maternal phenylketonuria; methylmercury poisoning; congenital rubella; congenital cytomegalovirus.

It can also arise from various syndromes, such as Cornelia de Lange, Cat Meow, Down, Rubinstein-Taybi, Seckel, or Smith-Lemli-Opitz, as well as types 18 and Trisomy 21. On the other hand, there is hydrocephalus, which is characterized by an excess accumulation of fluid in the skull.
It is worth mentioning that in the past hydrocephalus was known as "water in the brain" although it is actually cerebrospinal fluid, which is found around the spinal cord and brain.
It should be noted that the World Health Organization ( WHO ) produces tables with the expected head circumference according to the age of boys and girls. These data are taken as healthy patterns of child growth and serve pediatricians as standards.