Your Baby's Growth: 1 Month

How Much Will My Baby Grow?

During month 1, babies grow quickly in both weight and length.

Your baby will gain about 1–1½ inches (2.5–3.8 centimeters) in length this first month and about 2 pounds (907 grams) in weight. But it’s also OK if your baby grows a little more or a little less.

Feeding Cues to Watch For

At this point, you're learning the signs that your baby is hungry or full:

• When hungry, babies may seem restless, cry, stick out their tongue, or suck on their hands and lips.
• When full, babies probably don't seem interested in feeding or just fall asleep after feeding.

Your baby may go through periods of increased hunger and fussiness. This increase in hunger means your baby is going through a period of fast growth (a growth spurt). If you breastfeed, you might find your baby wants to eat more often (sometimes every hour!) during certain times of the day. This is called "cluster feeding." Formula-fed babies may want to eat more often or will drink more formula than usual during feedings.

How Is My Baby’s Growth Checked?

At your baby’s checkups, healthcare providers measure your baby's weight, length, and head circumference. They put this information into a growth chart (there are different charts for boys and girls). The growth chart lets them see if your baby is growing at the right pace. Whether babies are big or small for their age now doesn’t necessarily mean they will be big or small when they are older. What matters most is that your baby is growing steadily.

Babies who were born prematurely may need special formula or “fortifiers” added to the formula to give more nutrients and calories. Doctors may want to check growth more often during the first few months to make sure the baby is growing enough. It can take a while for babies born early to catch up, but as long as they are growing steadily, it’s usually OK.

What Happens if My Baby’s Growth Is Slow?

If your baby isn’t growing at an expected pace, the health care provider will check your baby and ask you:

• How many feedings a day does your baby get? At 1 month, a breastfed baby may feed about 8 times in a 24-hour period (roughly every 2–3 hours); bottle-fed babies usually eat less often, perhaps every 3–4 hours.
• How much does your baby eat at each feeding? A baby generally nurses for at least 10 minutes, should be heard to swallow, and should seem satisfied when done. Bottle-fed babies may drink up to 4–5 ounces (118–148 milliliters) at a time.
• How often does your baby pee? Babies should have at least 4–6 wet diapers a day.
• How often does your baby poop each day? The number of bowel movements (BMs, or poops) can vary a lot. Some breastfed babies poop with every feeding, but they also might not poop for a day or more. Most formula-fed babies poop at least once a day but others poop more or less than that.
• What does the poop look like? Breastfed babies' stools tend to be soft and slightly runny. The stools of formula-fed babies tend to be a little firmer. Whether your baby is breastfed or formula-fed, the pooping pattern is probably OK as long as the poop is not hard and doesn't have mucus or blood in it.

The health care provider will make some recommendations so your baby gets enough to eat. If you breastfeed, it might help to see a lactation consultant. This person can answer any questions you have and make sure your baby gets enough breast milk.

The health care provider may want to see your baby sooner than the next regular checkup, just to make sure your little one is growing OK.

Can My Baby Gain Too Much Weight?

Your baby will keep growing quickly for the next few months. You don’t need to worry about your baby gaining too much weight at this age, so feed your baby whenever your little one seems hungry.

Still, it’s OK to start some healthy habits with your baby:

• Stop a feeding when your baby seems satisfied. As long as your baby doesn't have trouble gaining weight, you don’t need to “top off” a feeding with a few extra minutes on the breast or more formula.
• Avoid giving babies this age juice, cereal, or other foods. They get the nutrition they need from breast milk or formula. Also, starting juice or foods early can cause them to gain too much weight.
• Never water-down formula to try to slow weight gain. Babies this age don’t need extra water.

When Will My Baby’s Growth Be Checked Next?

Unless your baby needs to come in sooner, the doctor will see your baby and check growth at the 2-month checkup.

Call the doctor if you have any concerns about your baby’s growth or health.