In their first year of life, babies often triple their birth weight and add about ten inches in height. But all that growing doesn’t come at the same pace, and the culprit is growth spurts, which are relatively predictable.
Most infants have between five and seven growth spurts in the first year, though this varies depending on a number of factors. In general, many pediatricians and parents find that infant growth spurts occur at:
- 7 – 10 days
- 3 – 6 weeks
- 3 months
- 6 months
- 9 months
The first few weeks of a baby’s life may have multiple, smaller growth spurts, and some of these periods may go unnoticed simply because parents are still dealing with the new routines and responsibilities of caring for a newborn.
But for other parents, these growth spurts are more noticeable because of changes in their baby’s behaviors. Eating, sleeping and temperament can all be affected by growth spurts, and many parents find it helpful to know when these occur.
“It has been my experience as a newborn care consultant that parents haven’t been prepared for these changes and need assistance determining a growth spurt and assurance that their baby is in fact healthy and ‘normal’,” says Brittney Kirton, an International Board Certified Lactation Consultant and Registered Holistic Nutritionist.
When you know when to expect infant growth spurts, it can be easier to handle the challenges of new and different routines, crankiness and other symptoms that come with your baby’s growth.
Why Growth Spurts are So Noticeable
An infant’s typical growth trajectory through the first year looks something like this: one-half inch to one inch of height each month in the first six months, and about one centimeter per month from six months to one year. Babies generally double their birth weight by four or five months and triple their weight by their first birthday.
While growth spurts in older kids happen over the course of years, infant growth spurts often happen in just a few days. According to Dr. Michelle Lampl, infants can grow up to 9 millimeters in one 24-hour period.
This explains why growth spurts can be such tough times for babies – and parents. That much growth at once is likely to make your baby extra sensitive, and knowing this can help parents better prepare for the coming days.
“On a practical, everyday level, it helps parents understand their infant’s behavior and patterns,” Lampl says.
With so much growth in such a short time frame, it’s easy to see why babies have a hard time adjusting. These growth periods can affect how your baby sleeps, feeds and interacts with his or her surroundings, and recognizing the symptoms can help ease your concerns about your baby’s changing behavior.
Common Symptoms of Infant Growth Spurts
During growth spurts, your infant may be more irritable, sensitive and crankier than usual. This may be more noticeable with some babies, while others will undergo these periods with no major changes in behavior.
There aren’t any hard-and-fast rules when it comes to your baby’s behavior – although growth spurts can be to blame, your little one is often undergoing a number of changes, such as teething, that can also affect their behavior.
It’s also important to remember that many times you simply won’t know what’s bothering your baby when they act different than normal.
Growing babies are hungry ones, so don’t be alarmed when your infant seems to be feeding more – and more frequently. Breastfed babies may be hungry at more times during the day (and night), and formula-fed babies may require more formula than normal with each feeding.
All that growing requires extra calories, so your baby may naturally feel the need to drink more. This can be difficult to adjust to, but it’s a natural part of the feeding cycle that helps baby gain weight and size, and often helps breastfeeding moms improve their milk supply with frequent feedings.
Irritable Baby Syndrome
Early infant growth spurts – during the first few weeks – can be shorter, but they may be more difficult on your infant. You may find them harder to soothe, even with your usual routines and techniques, and they may seem clingier than normal.
There’s no easy fix for these rough patches, so just know that your baby may be more sensitive during growth spurts because they’re more tired and hungry than usual. They’re undergoing massive changes relative to their size, so it stands to reason that they’ll be hard to soothe during these times.
More Sleep – or Trouble Sleeping
Parenting is full of paradoxes, and this is one of them: your growing baby may sleep more than usual, but he or she also might have trouble napping or sleeping at night.
One study found that “growth spurts usually occurred within two days of the increased sleep” period and that each hour of additional sleep meant a 20 percent increase in the chance that it was due to a growth spurt.
There are even differences in sleep for each gender, with Dr. Lampl’s study finding that “boys experienced longer sleep bouts, and growing girls had more sleep bouts.”
So if your little one seems to be sleeping more than normal, they may be preparing for a growth spurt. On the other hand, if they’re overly tired or hungry, they may have difficulty falling asleep at their normal nap and bedtimes. They may also nap at odd hours because they didn’t fall asleep at their normal times.
How to Deal with Growth Spurts
Be Patient and Don’t “Watch the Clock”
There’s a parenting maxim that says the days are long but the years are short, and this may seem even more true during your baby’s growth spurts. They will be cranky and feel out of sorts, and the worst thing you can do is count down the seconds and minutes until its over.
“Don’t watch the clock for how long baby has been nursing,” says Certified Breastfeeding Educator Cheryl Taylor. “Don’t watch the clock for how long it’s been since baby last wanted to nurse. Don’t watch the clock for how many times you’ve been awakened that night to nurse.”
This can be especially difficult for parents going through growth spurts around 3 – 6 weeks. By this time, you’ve had enough time with your baby to get to know his or her habits and routines, so getting thrown off of your “first” feeling of security can be overwhelming. Future growth spurts may not seem as bad, then, because you’ll be more used to constantly adjusting.
In the big picture, growth spurts go quick, and sometimes you won’t even notice them at all. If you’re facing particularly rough days, just know that they’ll pass sooner than you think, even if it’s hard to keep that perspective in the moment.
Be Flexible with Your Baby’s Schedule
With growth spurts, nap times, feeding times and every other part of your routine may get out of sync. Expect these changes so that when they happen, you’re not completely blindsided. It’s more than okay to be flexible with your baby’s schedule during growth spurts, and regardless of your thoughts on routine, you’ll find that it’s easier to go with the flow during these days.
This may be difficult if you’ve (finally) found a routine that works great for you and baby, but know that at every stage of growth and change, your routines will be disrupted, so the quicker you adopt this mindset of constant change in routine, the more likely you’ll encounter the next stage’s challenges with confidence.
Grab the Baby Carrier
Look, imagine if your body doubled in size in five months, or tripled in one year. It sounds painful, and there’s a reason babies become extra fussy during their growth spurts.
If it helps, give your baby extra carrying time to help them soothe. This might mean wearing a baby carrier around the house, or putting in more tummy time than usual. These spurts are mentally and physically exhausting – both for baby and parents – so ride the wave together by getting close and offering extra comfort to your little one.
Watch for Other Issues
Although growth spurts can be the root of your baby’s different behavior through the year, consider other issues that may be occurring as well. If your baby is sick, for example, this can briefly affect how much she will act – and grow.
“Sick babies temporarily divert their energy into healing rather than growing,” writes Dr. Sears in The Baby Book. “During prolonged colds your baby’s growth may level off. Expect catch-up spurts after the illness is over.”
A sick baby can also have many of the same symptoms as one going through a growth spurt: tired, cranky and apt to change their routines. Recognizing the symptoms of illness in a newborn of infant is important, and can affect your options for managing your baby’s health moving forward.
Depending on your baby’s age, he or she may also be dealing with teething issues. The American Dental Association offers a chart on teeth eruption, and says that most babies see teeth start to erupt by six months – also one of the prime times for growth spurts.
And of course, your baby could simply be adjusting to new changes in their physical and mental development. Just when you think you’ve found a good routine, your baby will find a way to change things up and keep you on your toes.
Change is the only constant with these little humans, so if you don’t have exact answers to your baby’s changing behavior, take comfort in knowing that most parents are in the same boat. Enjoy!