When you were pregnant, you lived for sonograms. Now that you're a mom, your newborn's growth chart -- what he weighs, the percentile he's in -- has your full attention. Be reassured that most babies gain as they should, says neonatologist Nancy Wight, M.D., medical director of lactation at Sharp Mary Birch Hospital for Women & Newborns, in San Diego. Use this guide to make sense of your wee one's pounds and ounces.
Days 1 to 14
It's expected your baby will drop a few ounces in the first days after he arrives. That's okay because infants are born with extra water weight to tide them over until your milk comes in. Colostrum, a nutrient-rich, thick substance that your breasts produce after delivery, has everything your baby needs at this point, says Jennifer Shu, M.D., a pediatrician in Atlanta and coauthor of Heading Home With Your Newborn.
Once your milk comes in, at two to five days post-birth, your baby should begin to gain back the ounces he lost, hitting his birth weight between days 10 and 14. "I like to see at least a half ounce of weight gain a day during this time," says Dr. Shu. If your newborn's weight dips by more than 7 percent during his first couple of days (say, a 7-pound newborn loses more than 8 ounces) or he takes longer than two weeks to return to his birth weight, see your doctor, who may advise supplementing. Formula-fed babies are much less likely to have trouble gaining weight than breastfed babies. Bottle-fed infants are more inclined to gain too much weight because formula is more concentrated than breast milk, and parents tend to want their babies to finish the bottle, says Dr. Wight. (Don't push. When your child turns his head away, he's done.)
Take careful note of those soiled diapers. "In the first three days, a baby will pass dark meconium stools. Between days three and four, those should change to the typical yellow, soft breastfed stool or darker, firmer formula stool," explains Richard Schanler, M.D., director of neonatalperinatal medicine at North Shore Long Island Jewish Health System, in New Hyde Park, New York. If your little one's stools aren't making this transition, he may not be getting enough milk. In the first two days, newborns tend to pass about one stool a day. On day three, they pass about three stools, and slowly this number increases until they poop after each feeding, or eight to 12 times a day, for the first couple of weeks. Your baby may produce two to three wet diapers a day in the first two days, but this will increase to six to eight per day by the end of the first week. Call your pediatrician if you find your peanut's pee and poop counts aren't adding up.
Understanding Your Baby's Growth Chart
Children grow along their own curve, which is why a baby who is in the 5th percentile and has always been in the 5th percentile is less of a concern than a baby in the 50th percentile who suddenly starts to drop. "If we see an infant falling significantly on the chart, say from the 60th to the 10th, we'll have the baby come in for more frequent weight checks and try to feed her more," says Dr. Shu. "If she's eating well but still not gaining, we'll run tests to rule out an underlying cause, like a food allergy."
Make sure your pediatrician is using the weight chart from the World Health Organization (WHO), whether your baby is breastfed or formula fed. In 2010, the Centers for Disease Control and Prevention (CDC) recommended pediatricians plot growth with this chart for children under age 2, but not all doctors have made the switch, says Dr. Wight. "The previous, decades old growth chart is based on formula-fed babies. It can make breastfed babies, particularly when they're between 4 and 8 months old, look as if they're falling off the charts, when they're healthy."