0-1 years old is the fastest baby growth and development period in a person’s life cycle. This article has compiled the currently recognized infant growth and development data in China for parents. When we say whether a baby is growing well, we often use the ” common evaluation indicators for infant physical growth ” to evaluate. The four major indicators are weight, height, head circumference , and chest circumference . Among them, height and weight are intuitive indicators that reflect the feeding and nutritional status of infants.
Neonatal period of Baby growth
Weight changes: Newborns may have physiological weight loss after birth , dropping to the lowest point 3-4 days after birth and returning to birth weight 7-10 days later. The weight loss should not exceed 9% of the birth weight. Premature babies recover their weight more slowly.
Changes in height: The average height at birth is 50cm, and it increases by 1cm when the baby is one month old, reaching an average of 51cm.
Changes in head circumference: The fastest period of baby’s head development is the first six months after birth, and the average head circumference of a newborn is 34cm.
Changes in chest circumference: At birth, the chest circumference is slightly smaller than the head circumference, which is 1 to 2 cm, at 32 to 33 cm.
After one month – 12 months of Baby growth
Weight changes: The baby’s weight increases at a non-uniform rate, and the weight gain rate gradually slows down as the baby grows older. Usually, a full-term baby gains an average of 600 to 1000 grams per month in the first three months after birth, and the weight at three months of age is about twice the weight at birth; the weight gain rate slows down from 4 to 6 months, with an average monthly increase of 500 to 600 grams. From 7 to 12 months, the average monthly increase is about 300 grams, and the weight reaches 9.6 to 10 kg at 12 months of age, which is about three times the weight at birth.
The normal baby’s weight can be roughly estimated according to the following formula:
1 to 6 months: weight (kg) = birth weight (kg) + age in months × 0.7 (kg);
7 to 12 months: body weight (kg) = 6.0 (kg) + age in months × 0.25 (kg).
Changes in height: In the first three months after birth, the average height increases by 4 cm per month, and the height of a three-month-old baby can reach 60-62 cm. In the fourth to sixth months, the average height increases by 2 cm per month; in the second half of the year, the average height increases by 1 cm per month; at the age of one year, the height reaches 75-76 cm, which is about 1.5 times the birth height.
Changes in head circumference: The average head circumference of a newborn is 34cm, with a total increase of 9cm in the first six months; and an increase of 3cm in the second six months, reaching an average of about 46cm at one year old.
Changes in chest circumference: At birth, chest circumference is slightly smaller than head circumference, 1 to 2 cm, at 32 to 33 cm; at 1 year old, chest circumference is approximately equal to head circumference.
The changes in these data in the first year of life, each step embodies the tenacity and hope of life. These are not just changes in numbers, but also vivid footnotes of the healthy growth of babies. As we can see, every baby is a unique miracle. They thrive in their own pace and way, nourished by love and care. As a parent, being able to accompany and witness all of this is undoubtedly the happiest and most precious experience.
