The main question that worries relatives and friends who learned about the baby’s birth is its height and weight. Why are these metrics so important? Yes, because the pediatrician, focusing on these data, assesses the general condition of the newborn. No less important is the increase in weight in newborns by months, which must meet certain standards. They are used by pediatric doctors around the world.
Birth rates
The growth and weight of the baby immediately after birth depends on the set of genes inherited from the parents, the quantity and quality of the mother’s nutrition during pregnancy, the sex of the baby, and some other reasons. Normally, the average growth of a full-term newborn is from 46 cm to 56 cm, while the weight is in the range from 2600 g to 4000 g. In addition, usually the mass of the baby increases with each subsequent pregnancy of the mother, that is, the born child is heavier than his older brother or sister by 300-500 g. The body weight of boys at birth differs from the weight of girls in a big way by 200-300 g.
There is also a special relative indicator - the Ketle index, which helps to assess the ratio of the mass and growth of the newborn. To calculate it, you need to divide the weight in grams by the height of the baby in centimeters. Normally, the Quetelet index ranges from 60 to 70 units. For example, in a baby born with a mass of 3500 g and a height of 53 cm, this figure is 66. Accordingly, it is normal.
Norms of loss and weight gain in children up to a year
The subsequent weight gain in newborns by months occurs according to certain rules. During the first days of life, the baby loses from 150 to 300 g, and this is quite normal. A natural decrease in body weight is associated with loss of fluid through the skin, the release of meconium and the normalization of breathing. After a couple of weeks, the indicators in most newborns correspond to body weight at birth.
The most intensive weight gain in newborns by months occurs in the first 2-3 months of life and is respectively 180-300 g per week. By six months, this figure is decreasing. A child at this age normally doubles its mass at birth. At 8-9 months of life, the baby is gaining about 350 g per month. By the year its weight should be already 3 times more than at birth.
Every young mother cares about the weight gain of the newborn. The table below will help you better navigate this indicator.
Child age | Average increase per month, g |
| 1-3 months | 750 |
| 4-6 months | 700 |
| 7-9 months | 550 |
| 10-12 months | 300 |
There is also a special online newborn weight gain calculator. It can be used to determine the normal body weight of a child up to a year.
When the weight gain in newborns by month differs significantly from the figures given in the table, it is necessary to find out the reasons for the deviation from the norm. Low body weight can be associated with malnutrition of the baby. If underweight is observed in a breastfed baby, then measures may need to be taken to increase lactation. Overweight is more common in babies who are breast-fed. In any case, the pediatrician in whom your child is being observed should find the cause of the deviation from the norm and suggest a way to eliminate it.