Weight gain among infants: How much
During the first year of life, a baby’s weight and their overall weight gain is the measure most frequently discussed by doctors to assess their development. Below parents will find some valuable information that will help them better understand this metric of infant development.

Normal birthweight for babies

The average newborn weighs 7.25 pounds and measures 19.5 inches long, according to the National Center for Health Statistics. Boys have a slightly larger head, with a circumference of about 13.5 inches to girls’ 13.3. It’s typical for a baby to drop 5% to 10% of her total body weight during the first few days after birth, so don’t panic if you notice this. It’s due to fluid loss through urine and stool, and because breast milk is mostly collustrum. They’ll start to gain weight again as breast milk comes in, and should be back up to their birthweight by the second week.

Typical weight gain for babies
From the first week to about 3 months of age, babies typically gain around an ounce a day, or about half a pound per week. Growth surges often occur around the third and sixth week. From 3 to 6 months, growth will slow down to about half-a-pound in weight gain every two weeks, or around half-an-ounce per day. By 6 months they should have double their birthweight (though this can sometimes happen as soon as 4 months). At 6 months this pace will slow down a little, but will continue at around a pound of weight gain per month up until 12 months, although it may fluctuate more because children start expending more calories as they become more mobile. By a child’s first birthday, the typical youngster will have tripled his birthweight.

However, parents shouldn’t automatically hit the panic button if a doctor says your baby isn’t putting weight on fast enough. A 2013 British study of more than 11,000 kids found that most infants who were slow to gain weight in the beginning will catch up to their peers and be a healthy, normal weight by age 13. Every infant has their own unique path to development, and these weight guidelines are merely a tool to flag other problems. Atypical weight gain does not, by itself, mean there’s a problem.

My baby is on formula. Does this make a difference in weight gain?
No. While breast milk is the ideal food for babies in terms of nutrients and antibodies, infants should gain the same amount of weight whether on breast milk or formula.