Infant growth: What's normal?

Probably not. Healthy infants come in a range of sizes. The rate at which your infant grows in the first year depends on several factors, including sex, diet and genetics. For example, boys usually grow faster than girls do, and bottle-fed babies tend to put on weight faster than breast-fed babies do.

Many healthy babies go through brief periods when they stop gaining weight or even lose a little weight. However, a doctor would likely be concerned only if an otherwise healthy baby doesn't gain weight for three consecutive well-baby exams during the first year.

Doctors monitor infant growth at well-baby exams using standard growth charts, which compare your baby's weight, height and head circumference with those of other babies who are the same sex and age. Infants who fall below a certain weight range for their age or who are failing to gain weight at the expected rate may require further evaluation.

So how much should you expect your infant to grow in the first year?

• Weight. Infants generally gain 4 to 7 ounces (118 to 207 milliliters) a week during the first month. After the first month, they gain an average of 1 to 2 pounds (0.5 to 1 kilograms) a month for the first six months. From six months to 1 year, they gain about 1 pound (0.5 kilograms) a month.
• Height. Infants generally grow about 1 inch (2.5 centimeters) a month during the first six months, and about 1/2 inch (1 centimeter) a month from six months to one year.

If you're concerned about your child's size or rate of growth, consult your child's doctor.

Adapted from the National Center for Health Statistics, 2000