Weighing InTypically, a newborn loses 10 percent of his body weight within the first week. But by the time he's two weeks old, he should regain or even exceed his birthweight, gaining about one ounce per day during the first three months. Between 3 and 6 months, this slows down to about 1 1/4 pounds per months, and then a 1/2 ounce per day between 6 and 12 months. With this rate of growth, your infant should double his birth weight by 4 to 5 months and triple it by the time he's 1 year old.
Reaching New HeightsMost newborns average length is 20 inches at birth. An infant grows in length at a rate of 3.5 cm per month in the first 3 months; 2 cm per month between 3 and 6 months; and 1.2 to 1.5 cm per month between 6 months and 1 year. The infant's length averages 75 cm at 1 year of age.
The Role Genetics PlayChanges in the growth rate are not unusual during the first two years of life, and depend on the size of the parents (i.e., large infants born to small parents tend to slow their growth, whereas small infants born to large parents tend to accelerate it during the first two years of life.) In such cases, the determinant of small size is genetic and should not raise concerns. In other words, the apple doesn't fall far from the tree.
Conditions that Hinder GrowthNutrition is the most important factor that influences growth. Conditions that might prohibit an infant from getting proper nutrition include:
- Structural malformations of the face and mouth, including cleft lip and palate.
- Neurologic disorders leading to the inability to suck and swallow normally.
- Gastrointestinal diseases manifesting with vomiting and/or diarrhea.
- Psychosocial problems as in child neglect or disturbed mother-infant relationship.
- Cardiac or respiratory disease where exhaustion and labored breathing may lead to inadequate dietary intake.
This is why it's important to pay special attention to symptoms suggesting illness (including vomiting, diarrhea, feeding difficulties and respiratory distress), as well as your baby's eating patterns and general behavior.
In infancy, many children who fail to thrive show developmental delays and abnormalities of posture. This is why malnutrition during the critical period of brain growth should be identified promptly and treated vigorously to minimize central nervous system problems.
The content on these pages is provided as general information only and should not be substituted for the advice of your physician.