4-Month Sleep Regression: What New Parents Should Know


Written by Dr. Michael Breus

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Just when you thought your 4-month-old had settled into more consistent sleep, you may find yourself being woken up at 3 a.m. by a fussy baby.

In the first months of life, your baby is still building the brain circuitry necessary to sleep through the night. This process unfolds over many months, and since every child develops at a different pace, they may experience interrupted sleep at different times. While many babies begin to settle into a more regular sleep pattern when they are around 4 months old, it is still common for them to experience periods of interrupted sleep.

The 4-month sleep regression can be frustrating and challenging for caregivers, but it’s important to remember that unpredictable sleep patterns are a temporary and normal part of an infant’s development. Learning the details about 4-month sleep regressions can help parents and caregivers get through this period while fostering healthy sleep habits for the future.

What Is the 4-Month Sleep Regression?

The 4-month sleep regression is a disruption in a baby’s sleep patterns around their fourth month, and it may occur after they’ve recently taken steps toward better sleep. From the moment a baby is born, their brain and body are developing and growing. This includes big changes to the way they sleep that play out over the first months and years of life.

The concept of sleep regressions has been around for decades. The original theory states that all infants go through distinct periods of disorganized sleep, also known as regressions, at certain ages. According to the theory, each regression corresponds to specific developmental milestones.

Most pediatricians today agree that not all infants undergo precisely timed sleep regressions. However, it’s normal for babies to experience shifts in their sleeping and feeding patterns at various times in their development. And for many families, changes in their new baby’s sleep patterns occur around the 4-month mark.

A sleep regression at 4 months of age can be especially frustrating for parents because a baby often has just started to sleep for longer stretches. New parents can feel like they’ve left the newborn stage behind only to have their infant return to waking up several times during the night. In the face of this frustration, it may help to know that these changes are temporary and are a normal part of the developmental process.

Signs of the 4-Month Sleep Regression

The primary signs of a 4-month sleep regression involve a reappearance of sleep difficulties after a period of improved sleep. Examples of these sleep difficulties include:

  • Trouble falling asleep
  • An increase in nighttime awakenings
  • More fussiness and crying at bedtime or during awakenings
  • Disrupted naps

When they occur, sleep regressions most often only last for a short period of time. However, just one or two nights of poor sleep don’t usually reflect a sleep regression since sleep can be briefly thrown off by an illness or a change in routine.

It is also important to remember that sleep patterns vary considerably from child to child in the first six months of life. As a result, sleep regressions may be part of the expected ups and downs of infant sleep.

Naps at 4 Months

Infants between 4 and 12 months old need 12 to 16 hours of sleep each day, which includes daytime naps.

Infants need a great deal of sleep to promote brain development. They don’t have the established sleep patterns that allow older children and adults to sleep soundly through the night, so napping can help your 4-month-old get the sleep they need.

Napping habits can vary among children, and daytime sleep patterns may fluctuate for several months. For a 4-month old, naps generally range from 30 minutes to two hours with one to four naps each day.

Changes in your baby’s napping are normal at this age, but you can try to develop a schedule that provides them with the sleep they need. Avoiding naps too late in the day may help prevent sleeping problems at night.

Why Does the 4-Month Sleep Regression Happen?

There are many potential causes of a 4-month sleep regression. At this age, a baby is growing and changing at a rapid rate. While this growth is important for hitting developmental milestones, it doesn’t always translate to sleeping peacefully through the night.

Different aspects of a child’s health and development can play a role in their sleep disruptions.

  • Evolving sleep patterns: Circadian rhythm is a 24-hour internal clock that promotes alertness during the day and sleep at night. Babies must develop their circadian rhythm from scratch, which is why it is normal that sleeping through the night can occur in fits and starts over the first year of life.
  • Overstimulation: At 4 months, many babies gain new physical abilities and greater ability to interact with people and their environment. In some cases, they may have sleep challenges from becoming overstimulated before bedtime.
  • Illness: Even minor illnesses may cause discomfort to a baby and disruption to their normal sleep pattern.
  • Teething: Some infants begin teething around 4 months old. Teething can be a source of pain and affect normal eating and sleeping.

While these issues may play a role in a 4-month sleep regression, it is not always possible to identify the precise reason that a baby begins having sleeping problems.

Do All Babies Experience the 4-Month Sleep Regression?

Infants establish sleep patterns at different rates, so not all of them experience a 4-month sleep regression. Children can experience sleep disturbances at any point in their early life, and babies may go through a sleep regression at 6 months, 8 months, 12 months, 18 months, or at other times in between.

It is natural for caregivers to wonder whether their child’s sleep habits are healthy. The key takeaway is that sleep interruptions at 4 months are a normal and usually short-lived part of infant development.

How Long Does the 4-Month Sleep Regression Last?

There is no set amount of time that a sleep regression lasts, but sleep difficulties may happen for anywhere from a few nights to a few weeks.

Although every child is different, the 4-month sleep regression is typically a small hurdle on a baby’s way to sleeping through the night. Providing support and a consistent routine can encourage healthy sleep and may reduce sleep problems.

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Tips for Coping With the 4-Month Sleep Regression

The road to sleeping through the night can be a bumpy one for new parents. Sleep disturbances at 4 months are a normal part of development for most babies. However, there are steps that you can take to introduce your baby to healthy sleep habits.

Establishing good sleep practices can help ease your family through the difficulties of the 4-month sleep regression. It will also help lay the groundwork for positive bedtime routines and quality sleep for years to come.

Keep in mind that at 4 months old, it is normal for your baby to be unable to regularly sleep through the night. This means that waking up in the middle of the night is expected. Nevertheless, certain tips may help reduce nighttime wakings and support good sleep over the long-term.

  • Stick to a routine: Establishing a consistent bedtime routine promotes healthy sleep. For infants, this may include feeding, a warm bath, gentle massage, and rocking. Just remember not to be too rigid with any routine. Follow your child’s tiredness cues, even if they don’t always match up with the planned schedule.
  • Encourage a return to sleep: It’s normal for infants to wake up frequently throughout the night, but ideally they learn to fall back asleep on their own. Keep nighttime visits quick and quiet without turning on the lights, and avoid bringing your baby out of the bedroom.
  • Encourage dozing off in bed: It may help to try putting your baby to bed when they’re drowsy but before they’ve drifted off to sleep. This can help them create a mental association between being lying in bed and falling asleep.
  • Make feedings strategic: Try to plan to feed your baby according to a schedule that fits with their preferred sleep pattern. Many babies don’t need nighttime feedings, so only feed at night if your baby seems hungry.
  • Avoid late naps: Napping too late in the day may create more trouble for your baby when they are trying to fall asleep at night.
  • Maintain a sleep schedule: Keeping a standard bedtime can help get your baby accustomed to a regular routine.
  • Stay active during the day: Daytime activities give your baby time to learn and practice important skills, and exposure to daylight can also help them get used to a typical day-night circadian rhythm.
  • Avoid overstimulation: Try to keep toys and other distractions out of bed. Look for ways to help your baby wind down before bedtime instead of having screen time or other things that might stimulate their mind.
  • Consider white noise: If your baby seems to be disrupted by nearby sounds, you can see if they get comfort from a white noise machine.

When to Talk to Your Pediatrician

Your 4-month-old should get 12 to 16 hours of sleep every day, including naps. Disorganized sleep patterns are normal for most infants and toddlers, and short-lived sleep regressions are usually not a cause for concern.

It’s generally a good idea to review your baby’s sleep patterns with their pediatrician at every check-up. You should also talk to your pediatrician if your baby has disrupted sleep and you notice any other symptoms of potential health concerns, such as:

  • Loud, frequent snoring or abnormal breathing during sleep
  • Missed developmental milestones
  • Lack of growth or excess weight gain
  • Problems with adequate feeding

How to Care for Yourself During the 4-Month Sleep Regression

Whether you’re a new parent or a veteran caregiver, sleep regressions are tough. The promise of a full night’s sleep feels tantalizingly close, and then your 4-month-old suddenly starts having disruptive nighttime awakenings.

While it’s tempting to focus solely on your infant’s sleep, you shouldn’t neglect your own needs in the process. A few tips can help you get through your baby’s 4-month sleep regression.

  • Remember your own sleep habits: It may not be realistic to get a full eight hours of uninterrupted sleep, but you can still steer clear of the usual traps that harm your sleep. Try to avoid alcohol and caffeine close to bedtime, get a little bit of physical activity and sunshine during the day, and reduce screen time late in the evening.
  • Trade night duties: If you share caregiving responsibilities with a partner, try taking turns during the night. This can give one caregiver a chance to relax, recharge, and catch up on sleep. You can also split nights into an early and late shift.
  • Ask for help: If you’re struggling, don’t be afraid to seek out support. Many family members, friends, and neighbors won’t hesitate to help a new parent, even if that just means freeing up time for a quick power nap.
  • Don’t expect sleep perfection: In the first year of your baby’s life, it’s doubtful that anyone in your household will get ideal sleep every night. You can do your best to foster good sleep habits for you and your baby, but worrying too much about getting the perfect night’s sleep can be counterproductive.


About The Author

Dr. Michael Breus

Clinical Psychologist, Sleep Medicine Expert

Michael Breus, Ph.D is a Diplomate of the American Board of Sleep Medicine and a Fellow of The American Academy of Sleep Medicine and one of only 168 psychologists to pass the Sleep Medical Specialty Board without going to medical school. He holds a BA in Psychology from Skidmore College, and PhD in Clinical Psychology from The University of Georgia. Dr. Breus has been in private practice as a sleep doctor for nearly 25 years. Dr. Breus is a sought after lecturer and his knowledge is shared daily in major national media worldwide including Today, Dr. Oz, Oprah, and for fourteen years as the sleep expert on WebMD. Dr. Breus is also the bestselling author of The Power of When, The Sleep Doctor’s Diet Plan, Good Night!, and Energize!

  • POSITION: Combination Sleeper
  • TEMPERATURE: Hot Sleeper

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