What to know about baby growth spurts

What happens during a growth spurt?

Is your baby suddenly acting a little different? If they're fussier than usual, sleeping less, or eating more, your baby might be going through a growth spurt.

During a growth spurt, your little one will add weight, length, and head circumference more quickly than usual. They may also hit a developmental milestone or master a skill they've been working on for a while.

Many parents find that the most noticeable sign of a growth spurt is their baby feeding more, so look out for times when your little one seems particularly hungry.

If your baby is breastfed, they may nurse for longer than usual or want to nurse more often. If they're formula-fed, they may still seem hungry after finishing a bottle.

Some babies sail through growth spurts without showing any obvious signs. You may take your baby to be weighed and see that their weight has jumped to a higher percentile, or notice that their new sleeper is suddenly tight at the toes.

When your baby is having a growth spurt, they may need more or less sleep than usual. There's some research showing that babies going through growth spurts become clingy, fussy, and unsettled. This can disrupt nap times and nighttime sleep.

When do growth spurts happen, and how long do they last?

Growth spurts can happen at any time. In young babies, they usually last for one or two days. In older babies, they can last up to a week.

Some experts believe that growth spurts are more likely at certain points in your baby's first year. Here's when your baby might experience one:

Between 2 and 3 weeks

Between 4 and 6 weeks

Between 6 and 8 weeks

At 3 months, 6 months, and 9 months

Each baby's growth pattern is different, so try not to worry if your baby doesn't seem to be having growth spurts at these times. They may have more spurts than this or fewer, and you might not even notice any particular spurts at all. It's all normal.

Are growth spurts the same as feeding spurts?

No, but they are related. Feeding spurts are times when your baby seems hungrier than usual. They may or may not be linked to a growth spurt.

During a feeding spurt, your formula-fed baby may want a bottle more frequently. Your breastfed baby may spend more time nursing and be fussy at the breast. They may go from nursing eight times a day to nursing between 12 and 14 times a day.

You may also hear or read about "frequency days," which are days when breastfed babies nurse more often, up to 18 times in 24 hours.

Surprisingly, there isn't a lot of research linking feeding spurts to increased growth, but it makes sense that when your baby's taking in more calories, they'll grow more quickly. Because of this, some people use the terms "growth spurt" and "feeding spurt" to mean the same thing.

What are other signs of a growth spurt?

Sleep changes

Just before and during a growth spurt, your baby may sleep more than usual. Waking up less at night or taking longer naps may be signs that they're channeling their energy into growing. One small study suggested that during a growth spurt, babies may sleep up to four and half hours more than usual over one or two days.

It's not clear exactly why this happens, but a protein called human growth hormone (HGH) is produced in the brain during sleep. HGH is crucial for growth, so sleep may provide the fuel that your baby needs to grow.

Some parents report that their babies seem to need less sleep during growth spurts – that they wake up more frequently at night, wake up earlier, or take shorter naps. This may happen because these babies are hungrier and are waking up more frequently to eat.

You may find these changes in your baby's sleep exhausting. It can be hard – especially if your baby is sleeping less – but take comfort in the fact that a growth spurt usually only lasts for a few days. Before too long, your baby's routine should be back to normal.

Behavior changes

During a growth spurt, your baby may be more restless and clingy than usual.

You may find that they want to be held all the time and cry when you try to put them down. Or you may notice that they're unsettled and weepy at times when they're usually laid-back and calm.

We don't know exactly what causes these changes in behavior. They may be due to your baby feeling tired or overwhelmed as they devote their energy to eating and growing.

There's also a theory that behavioral changes may be a sign that a developmental leap is coming. This may happen alongside a growth spurt or at a different time. So if your baby seems fussy or cranky, they may be getting ready to unveil a new skill, such as rolling over or crawling.

What should I do during a growth spurt?

Respond to your baby's cues and try to give them what they need, whether it's extra feedings, a morning nap, or quiet time and cuddles. Wearing your baby in a carrier may help them feel secure while giving your arms a break.

You may worry that your breastfed baby isn't getting enough milk during a growth spurt. But your baby's frequent nursing will increase your milk supply, and you'll most likely have more than enough for your baby's needs.

However, it may take a day or two for your body to catch up to your baby's hunger. If you breastfeed and you're worried that your baby isn't getting enough milk, check in with your baby's doctor, or a nurse or lactation consultant, for advice and extra support.

Help boost your milk production by letting your baby nurse as often as they want, and take care of yourself by eating good meals, drinking lots of fluids, and letting family and friends help out with chores.

If your baby is formula-fed, it's fine to give them an extra bottle if they want one. Or try adding an extra ounce or two of formula to their bottles. After the growth spurt, your baby may go back to wanting less formula at each feeding. Or, they may stick with the new amount. As your baby gets older – and their tummy gets bigger – they'll drink fewer bottles a day with more formula in each.

Is it a growth spurt or is something wrong?

Growth spurts can make babies sleepy and out of sorts, but they don't cause fevers, extreme irritability, or listlessness. These can be signs that your baby is unwell. Contact your baby's doctor if your little one shows any of these symptoms.

Likewise, if your baby's behavior, feeding, or sleeping habits change suddenly and you're concerned, ask the doctor for advice.

Growth spurts aren't the only explanation for a cranky, hungry baby. Teething, changes in routine, and minor illnesses can also affect your baby's feeding, sleep, and behavior.