Question
How much should a three-month-old baby weigh? If the baby weighed 6.2 kilograms at birth and now weighs 12 kilograms, is this within the standard range?
Answer
According to the formula for weight gain after birth, a three-month-old baby’s weight should be between 1.5 to 2 times their birth weight. For a baby who weighed 6.2 kilograms at birth, the standard weight should be between 9.3 kilograms and 12.4 kilograms. However, each baby’s growth pattern may vary slightly, and it is possible for the baby to be within this range even if their body condition is good. Additionally, the standard growth pattern for height is that full-term infants have an average length of 50 centimeters, growing approximately 25 centimeters in the first year, reaching about 75 centimeters at one year; during the 2 to 10-year period, height increases by an average of 5 centimeters per year. Based on these formulas, a three-month-old baby’s height should be around 55 to 56 centimeters.