Too Big? Too Little? Just Right?

Your newborn may seem to tiny and delicate — but not for long!

In the blink of an eye he will be packing on the pounds. Newborns typically range from about 5 ½ to 8 ½ pounds at birth, and lose about seven percent of that weight in the first few days.

Once good feeding is established, however, their growth is astonishing.

In the first month, expect your baby to gain about an ounce every day. By four or five months, most babies will weigh twice what they did at birth, and by one year they will plump up to almost three times their birth weight.

Infant growth charts assign a percentile to measurements of weight, length and head circumference. Your baby’s percentile represents where he stands with respect to other babies of the same age.

For example, if your baby is at the fortieth percentile for weight, it means that about 40 percent of same-age babies weigh more and about 60 percent of babies weigh less than he does.

Many babies start life at one percentile and eventually settle at a very different one. Your baby’s healthcare provider will track his growth on his growth chart at each regular visit. Very high, very low or changing percentiles may be cause for concern, but often require only continued close monitoring.

A baby’s weight should always be considered in relation to other growth measurements, particularly length. A baby at the tenth percentile for both weight and length may just be naturally petite, whereas a baby at the tenth percentile for weight and the ninetieth percentile for height may need more calories to support continued vigorous growth. Possible reasons for poor growth may include medical or developmental problems.

Many healthy babies have periods of slow growth, and some can even lose a little weight from brief illnesses. These periods are typically followed by rapid make-up growth.

Breastfed babies often gain weight faster than formula-fed babies in the first few months. This initial growth may seem alarming to you, but you should not be concerned. Since breastfed babies control how much they eat, they rarely overfeed.

Bottle-fed babies are at risk for overfeeding and excessive weight gain if caregivers are not paying attention to cues that indicate a full belly — such as a slowing sucking pattern or turning the head away from the bottle.

Keep in mind that there is no such thing as a perfect weight — every baby is different and usually finds the size “just right” for him.

Pediatrician Elizabeth Shashaty, MD, is on staff at Children’s National Medical Center and Medstar Georgetown University Hospital, both in Washington, DC.