A baby' s weight and height tell a lot about his physical development. From birth, the baby is weighed and measured and, especially in the first year of its life, its weight and growth measurements should be monitored by the pediatrician.

Infant weight and length at birth

Genetic inheritance and the time of gestation that the baby chooses to be born determine, in principle, its weight and height. Thus, the size of the parents influences the weight and height of the baby not only at the time of birth, but also in its subsequent development. Regarding the time of delivery, a distinction must be made between those born at term and those born before the 38th week of gestation. On other occasions, a maternal illness that did not allow her to receive enough food during pregnancy or gestational diabetes can also determine the weight and size of the baby at birth.

How much did the baby weigh?

This is the most frequent question answered by parents after the birth of their child, along with the name chosen for it. Below 2,500 grams, it is considered low weight in full-term babies, while above 4,000 grams, the weight is evaluated as high. The average value lies between the two measurements and is around 3,000 grams.

How much should the baby grow and gain weight?

Weight and height measurements are routine checks that your pediatrician will perform at each visit. It is important not to become obsessed with these measurements because the peaks of weight gain and growth are not always the same and, during the first year, they change every trimester.

Thus, during the first three months, weight gain ranges between 750 - 900 grams per month. Between the third and sixth month, it decreases and the gain is around 500 - 600 grams per month. Between the sixth and ninth month, weight gain is lower, between 350 - 400 grams per month. And finally, between the ninth month and one year of age, the monthly average is between 250 - 300 grams.

Weight and height chart for boys and girls

The tables on ideal weights and measurements are guidelines, an aspect that you should take into account when weighing and measuring your child. This guidance is NOT a substitute for your pediatrician's advice. Continue to respect and consider the monthly check-ups indicated by the doctor. It will be him who will give the last word on your child's physical condition.

The WHO table for boys and girls

Until April 2006, growth charts were based on a small infant population, of the same geographic origin and without distinguishing between breastfed and formula-fed infants. Fifteen years ago, the World Health Organization, WHO, aware of this situation and that these charts could be interfering with infant health care, decided to initiate a much larger study. The selected population includes children of diverse ethnicities and backgrounds and the novelty is that all of them have been fed with breast milk, which is considered the reference standard for feeding.