Material growth should be expressed by indicators that are easy to measure and represent a large population.

Commonly used morphological indicators include weight, height (body length), sitting height (top and hip length), head circumference, chest circumference, upper arm circumference, subcutaneous fat and so on.

Then, let's understand the requirements of each index one by one. Let's talk about weight first.

Body weight is the total weight of organs, systems and body fluids.

Among them, bones, muscles, internal organs, body fat and body fluids are the main components.

Because of the great changes in body fat and body fluids, weight is the most easily fluctuating among the body growth indicators.

Weight can be easily and accurately measured, and it is the easiest index to reflect children's growth and nutritional status.

In pediatric clinic, dosage and intravenous infusion are calculated according to body weight.

The birth weight of newborn is related to parity, gestational age, sex and intrauterine nutrition.

Postnatal weight gain should be the continuation of fetal intrauterine weight gain.

If the intake is insufficient within one week after birth, coupled with dehydration and meconium excretion, temporary weight loss or physiological weight loss may occur, about 3? Reached the lowest point on the 4th (3%? 9%), and then gradually pick up, to 7- 10 days after birth should be restored to birth weight.

If the weight loss exceeds 10% or the weight at birth has not recovered to 10 days, it is a pathological state, and the reasons should be analyzed.

If you feed it in time and reasonably after birth, you can reduce or avoid the occurrence of physiological weight loss.

Birth weight is greatly influenced by intrauterine factors, and it is closely related to nutrition, disease and other factors after birth.

With the increase of age, the weight growth of children gradually slows down.

According to the survey data of 1975, 1985 and 1995 in China, the weight gain of normal full-term infants in the first month after birth can reach 1- 1.5 kg, and the weight in the third month after birth is about twice that at birth. In the first year, the baby's weight gain in the first three months is about equal to that in the last nine months, that is, the baby's weight at 12 months is about 3 times (9kg) of that at birth, which is the fastest growth period after birth and the first growth peak. Weight gain 2.5 in the second year after birth? 3.5kg, the weight at 2 years old is about 4 times that at birth (12 kg); From 2 years old to early adolescence, the weight growth slows down, and the annual growth value is about 2kg.

The growth of children's weight is an unsteady growth, and the evaluation should be based on the change of individual children's own weight growth, and can not be evaluated by formula calculation, nor can the so-called "normal value" of the population be used as the "standard".

Another indicator of children's physical growth: What are the rules of height and sitting height?

Height refers to the sum of the length of the head, spine and lower limbs.

Most children under 3 years old are not easy to measure in standing position, so they should be measured in supine position, which is the so-called body length.

The difference between standing position and supine position is 1? 2 cm.

The growth law of height (length) is similar to that of weight.

The younger you are, the faster you grow, and there are two growth peaks in infancy and adolescence.

The average body length at birth is 50cm, and the body length grows fastest in the first year after birth, about 25cm；; In the first three months, the body length increased by about 1 1? 12cm, which is approximately equal to the growth value in the last 9 months. 1 year, with a body length of about 75cm; . In the second year, the growth rate of body length slowed down, about 10cm, that is, when the body length was about 85cm2; After 2 years old, the height increases by 5-7 cm every year.

After 2 years old, the annual height growth is less than 5cm, which means that the growth rate decreases.

The growth of height (body length) is obviously influenced by heredity, endocrine and intrauterine growth level, while short-term diseases and nutritional fluctuations are not easy to affect the growth of height (body length).

Sitting height (hip length) is the length from the top of the head to the ischial tubercle.

Consistent with the measurement of body length, the supine position of children under 3 years old measures the length of the top and buttocks.

The growth of sitting height represents the growth of head and spine.

Finger distance is the distance between the two fingertips when the upper limb is horizontally extended, which represents the growth of the long bone of the upper limb.