#1 Your Newborn Is Adjusting to Postnatal Sleep

Environmental changes can lead to behavioral changes, especially if the shift is jarring. There’s no bigger change than when your baby’s environment changes from womb to bedroom. Suddenly, she’s no longer sleeping in the cozy darkness of mom’s womb against a soundtrack of continuous whooshing and whirring. Instead, she’s faced with the endless expanse of her crib, the bright lights of the outside world, and strange new sounds that can disrupt her sleep times, such as the dog barking next door or the garbage truck clunking down the street. (And let’s face it, we hate those sounds too!)

Because every baby is born with a unique temperament, some babies may not need as much consoling from Mom and Dad during this time of transition. However, for those with less-than-mellow temperaments, this environmental shift can cause some complaints (i.e. those cries during sleep).

As your newborn adjusts to her new sleep environment, her sleep itself will likewise go through major changes.

• Sleeping to the beat of a new rhythm – When your baby was in the womb, melatonin (the hormone that promotes sleep) passed from mom to baby through the placenta and synchronized their internal clocks. This means your baby’s sleep patterns in utero were largely dictated by mom’s hormones (talk about following in Mom’s footsteps).

When this maternal-fetal synchronization is broken after birth, your little one establishes her own sleep cycle, independent of mom’s hormones. For some babies, this period of transition can be marked by agitated and unrestful nighttime sleep. To learn more about when babies learn to sleep on their own, read more in our linked blog.

• Cycling through a new sleep sequence – In the womb, your baby was doing more than growing. She was also sleeping. A lot. In fact, at 32 weeks, your baby spent roughly 90–95% of her time snoozing away, cycling between deep sleep, active sleep, and an indeterminate stage of sleep (likely due to her still-developing brain).

Out of the womb and in her crib, your baby’s sleep cycle consists of only two stages: REM sleep and NREM sleep. As your newborn nods off, her sleep cycle will look something like this:

• REM sleep – Almost immediately after falling asleep, your baby will venture into REM sleep, or rapid eye movement sleep. This stage of sleep is characterized by variable breathing, heart rate, brain wave activity, and eye movement speed, earning it the alternative title “active” sleep. The physical and mental activity that occurs during this stage may account for some of the wiggling and vocalizations that arise from your baby’s crib during sleep, particularly because active sleep makes up roughly half of your newborn’s time spent snoozing.
• NREM sleep – The second stage of sleep for newborns is NREM sleep, or non-rapid eye movement sleep. Due to this stage’s slow, even breathing, reduced heart rate, and lack of movement, it’s also known as “quiet” sleep. When transitioning between active sleep and quiet sleep, babies often startle, wake, and sometimes cry.

#2 Your Fussy Baby May Be Going Through a Sleep Regression

Infants tend to experience one or more periods of sleep regression, which are marked by worse-than-normal nighttime sleep. With sleep regression, you may find your baby fighting sleep, they suddenly wake more frequently, have difficulty falling back to sleep afterward, and/or act increasingly fussy. You may also notice that, after you think you’ve figured out how to get your baby to sleep without being held, they regress.

Sleep regressions are natural, and can be caused by both internal and external changes, such as the:

• Increase in stimulation from all sides – As your baby grows, he’ll start trying new foods (a shock after months of only breast milk on the menu), experiencing new adventures (like touching sand at the beach or meeting dogs at the playground), and learning new tricks (Mom, did you know I could crawl?). With all this excitement, you can’t blame your baby for not wanting to waste any more time on boring old sleep!

• Sudden changes in his physical body – Growth spurts and teething can cause minor discomfort, which may keep your baby from sleeping as peacefully as he used to.

• Heightened emotional, social, and cognitive awareness – Around the 8-month mark, your little man will begin to understand the concept of object permanence. That means when you’re not around, he knows you’re still somewhere. He may resist sleep to try to figure out, Where did Mom go? Can I go too? I can crawl there myself!
• Inconsistent or changing patterns of daily life – Implementing new feeding schedules or starting new daily routines (such as going to daycare) can be a shock to your son’s system (who knew babies were such sticklers for a schedule?). These types of changes in pattern can have a domino effect, causing a change in your baby’s sleep behavior.

#3 Your Baby Could Be Experiencing Night Terrors

We’ve all startled awake at one point or another after experiencing a frightening, all-too-real nightmare. As adults, this may rattle us for a few moments, but we’re usually able to shake it off and fall back asleep without too much trouble. After all, it was just a dream.

Although you might think your crying baby could be having a nightmare, she may actually be experiencing something a little different—night terrors. Although nightmares and night terrors are both sleep disturbances, there are important distinctions between the two:

• Nightmares – Nightmares are distressing, disturbing dreams that typically involve a specific danger and occur during REM sleep (the stage of sleep where we do the bulk of our dreaming). However, infants don’t experience nightmares. This particular type of sleep disturbance usually doesn’t become common in children until they’re about 2 to 4 years old, the same age they begin to see static dream images during their REM sleep. Before this age, infant REM sleep is believed to be dreamless.
• Night terrors –Night terrors are considered a parasomnia—an unusual, sleep-related behavior. They’re caused by an over-arousal of the central nervous system during NREM sleep, which can cause your baby to scream and cry while she’s still asleep. In fact, a key difference between nightmares and night terrors is that most people who experience night terrors don’t remember the event after they wake up. It’s also harder to wake someone who’s experiencing night terrors, as they’re technically in a stage of deep sleep.

Though uncommon, night terrors can develop in babies as early as 18 months old. While the nighttime cries of a baby experiencing night terrors can be distressing for any parent, it’s important to remember that your baby isn’t in danger, and she isn’t having a nightmare with frightening imagery. In fact, she isn’t even aware she’s making any commotion at all.

Although night terrors aren’t dangerous, if they continue to disrupt your baby’s sleep, talking with a pediatrician may provide steps you can take to reduce their prevalence.

How can I help my crying kiddo?

As much as it may contradict your parental superhero instincts, one of the best ways to help your crying baby is to wait a few minutes before rushing in to soothe him. This is because your baby may simply be fussing while he’s transitioning from one stage of sleep to another. If you swoop into his room and pick him up at the first cry of distress, you may create even more of a sleep disturbance. Plus, implementing this waiting period allows your baby time to self-soothe—a healthy habit he’ll need to develop to become an independent sleeper.

If your baby’s crying persists after waiting a few minutes, you can spring into superhero mode and try to soothe your crying kiddo with the following tips and tricks:

• Reassure him with verbal and physical cues – To help your baby feel safe, try making your presence known by softly cooing or whispering, or gently placing a hand on his belly. These delicate cues allow you to comfort your baby without overstimulating him, making it easier for him to fall back asleep after he’s settled down.
• Try swaddling or using a sleep sack – Swaddling is about the closest your baby will ever get to reliving the comforting warmth and coziness of Mom’s womb. In fact, research has shown that swaddled babies sleep longer and more soundly. However, it’s important to note that babies should only be swaddled with a blanket until they’re 2 months old (around the time they’ll start attempting to roll over on their own). For babies older than 2 months, a sleep sack offers a safer, similar solution. To learn more about sleep swaddles, sacks, and blankets, read our linked blog, When Can Babies Sleep With a Blanket.
• Consider co-sleeping or room sharing – If your baby’s crying is due to night terrors, you may want to consider co-sleeping—an evolutionary approach to soothing children who suffer from night terrors or nightmares. The research suggests that children feel safer when sleeping near their caregivers and that the heightened emotional security can mitigate night terrors.
• Adjust his room temperature for optimal comfort – If your baby is crying while trying to squirm out of his swaddle or onesie, you may want to check the thermostat to ensure he isn’t too hot or too cold. For babies, the recommended sleeping temperature is between 68°F and 72°F.

Understanding your baby’s sleep patterns and the possible reasons for their crying during sleep, from adjusting to a new environment, going through sleep regressions, to experiencing night terrors, can help ease your worries and equip you with the right approaches to soothe them. By implementing a few minutes of waiting before intervening, providing comfort with gentle cues, considering co-sleeping, adjusting room temperature, or even employing a swaddle or sleep sack, you can transform your superhero parent role into a sleep guardian, facilitating your child’s journey to peaceful and healthy sleep.<!–

This post has been reviewed for accuracy by the following medical professional:

Dr. Heather Soper, Certified Nurse Midwife

Heather has 15 years of women’s health and obstetrics experience. She is the owner of The Genesis Resort for Birth and an Assistant Professor of Nursing at James Madison University.

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