Baby Growth Spurt: What To Expect During Infant Growth Spurts

Baby Growth Spurts Are A Wild Ride So Don’t Get All Hung Up — Here’s What To Expect

May 13, 2021 Updated June 12, 2021

baby growth spurt
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Checkups are the perfectly rational place for parents to feel like they themselves are the ones being weighed (pass), measured, and pinched for ripeness. It’s easy to get emotional one way or another about baby development benchmarks and the wild rise and fall of baby growth spurts. Just take our loving advice, it’s bad policy. And many pediatricians agree. Percentiles for height and weight and trying to predict how much your baby is going to grow — and when — is a trap because it’s so different for everyone. All you can do is your best and hang on because baby growth patterns are a wild ride, so it’s best to just avoid getting all hung up.

That being said, baby growth spurts, which are a burst of intense growth over a short period of time, can come on quickly and happen several times in the first year, when babies will tend to triple their body weight. Generally, growth spurts happen during the first couple of weeks, at about 6 weeks, 3 months, 6 months, and 9 months. Sometimes a growth spurt hits overnight and a onesie that fit the day before won’t snap. Some growth spurts can last up to a week. Researchers even found babies tend to grow faster in the spring than at other times of the year, which is kind of wild.

Want to know what to expect? Here’s some information ahead of your little one’s next spurt.

Baby Growth Spurts Depend on the Baby

“In the first two years of life, it’s hard to predict what a child’s growth chart will look like,” The Cleveland Clinic’s Dr. Canh explains. “Babies hit many growth spurts. After age 2, we have a better sense of how they are trending in their growth and where they may eventually settle.”

And even after babies hit 2 years old, Dr. Canh says pediatricians are just looking for an upward trend, even just a slight one, which means there probably isn’t any reason to worry.

Signs of Baby Growth Spurt

  • Growing is exhausting so babies experiencing a spurt also need more sleep, according to researchers, which might be a bit of good news, but the downside is that they can get a bit cranky. Growing is hard but sleep is key to a baby’s development. So during growth spurts, their sleep schedule may become a little wonky. 
  • Has your baby turned into a tiny black hole that’s always hungry? Babies going through a growth spurt are going to be hungry. When a baby is growing, they want to eat all. The. Time. So just be prepared for a lot of breast and formula feeding! It takes extra calories to grow bigger, so they might suddenly get interested in cluster feedings or just need more volume. 
  • Baby might give you more attitude than usual because they may be in pain. As their muscles grow, it could be an uncomfortable process for them, so your baby might be fussier than usual. 

Newborn Growth Spurts (7 to 10 days and 6 weeks old)

Babies may lose a bit of weight during the first few days, but the first growth spurt during the first week should help bulk them back up. And keep feeding them when you can to maintain steady weight gain.

Per the Mayo Clinic, you’ll notice a newborn won’t eat the same amount every day. “During growth spurts — often at two to three weeks after birth — your newborn might take more at each feeding or want to be fed more often. Respond to early signs of hunger, rather than keeping a strict eye on the clock.” The Mayo Clinic adds five days after delivery, babies should be wetting no fewer than six diapers a day and show interest in feedings. If not, talk to your pediatrician.

Baby Growth Spurt (3 and 4 Months)

By 4 months old most babies will have doubled their birth weight, according to Dr. Cristy Wong. The 3- or 4-month growth spurt can come on fast, is likely to be the biggest of the first year, and will cause your baby to be cranky, sleepy, and hungry, just like the first couple. Dr. Michelle Lampl from Emory University says a baby at this stage can grow up to nine millimeters in just 24 hours during a particularly major growth spurt.

Later baby growth spurts during the first year aren’t as noticeable, but just like the others can cause your baby discomfort and require a little more care. If the baby is running a fever or acting out of the ordinary beyond a bad mood and being a little hungrier or sleepier than usual, call your pediatrician. No one knows your baby better than you do.

Keep these signs in mind so you can figure out if your baby is going through a growth spurt. And always remember, everyone is different, and no matter how big or small, your baby is perfectly glorious exactly the way they are.