The Four-Month Sleep Regression

What happened to my good little sleeper?

If you’re asking yourself that or have already asked yourself that, you may be experiencing the dreaded four-month regression. Here’s what it looks like: You thought things were getting better. You were getting longer stretches at night. Then suddenly, your baby started waking every two to three hours, or every hour, or every 45 minutes. And to make matters worse, it’s taking longer and longer for baby to fall asleep. When you used to be able to rock, bounce, nurse or feed and then transfer your baby in a short amount of time, it can now take much longer. And when you finally do put baby down, she wakes again shortly afterwards.

What’s happening?

The four-month sleep regression is in fact, not a regression at all. Instead, it is a sleep milestone. Baby’s sleep patterns become more adult like, and they stay that way for the rest of her life.

When your baby was a newborn, chances are he or she could fall asleep quickly and easily. You could hold your baby, wear your baby, nurse, bottle feed or rock your baby, and most likely, baby fell asleep easily and transferred easily to her crib or bassinet. According to The National Sleep Foundation, newborns spend 50% of their sleep time in REM sleep and 50% in NREM, which is quiet sleep. Adults spend only 20 to 25 percent of the night in REM sleep. The greater percentage of newborn REM sleep means that they more quickly and easily move through the light stages of sleep and into quiet sleep and then REM sleep. It is easier and faster for them to fall into a quiet sleep, and they less likely to wake after being transferred.

By 6 months, babies spend only 30 percent of their sleep in REM. Somewhere around the fourth month of baby’s life (but sometimes before and sometimes after), baby’s brain begins to mature, and her sleep patterns begin to be more adult-like. She starts spending less time in REM. It begins to take her longer to move from Stage 1 Sleep, (the lightest of the sleep stages) to Stage 2, which according to Tuck Sleep Foundation is characterized by decreased body temperature, decreased heart rate and an unlikelihood of awakening and Stage 3, which is deep sleep. She is also more aware of her surroundings, and in general, it is less easy for her to fall asleep. Like an adult, a child who is experiencing the “four-month regression” moves more slowly through the stages of sleep, from sleepiness, to light sleep, then to deep sleep. And because this regression is really a sleep milestone, the regression doesn’t “end” one day. However, many babies do learn to connect their sleep cycles on their own. When babies are put into their beds awake, they learn to go into the Stage 2 on their own, without rousing because they’ve been transferred. When they’re able to master these lighter stages of sleep on their own, they are more able to roll into the next sleep cycle after coming out of REM.

What can I do about it?

While you can rock your 6-week-old to sleep in 15 minutes, and put her down, if you try rocking your four-month-old to sleep she will likely startle awake as soon as you put her down. This is because she was still in the light stages of sleep when you tried to put her down. If you want to continue to rock your baby to sleep, it can take a very long time, maybe an hour, before she finally falls into deep sleep allowing you to put her down without startling her awake.

For babies who finish as sleep cycle in the night and experience an obvious wakening afterwards, it can be troubling for both the child and the parents if she doesn’t know how to transition to the next sleep cycle and get herself back to sleep. Unless she needs a night-feed or is sick, she is likely waking because she doesn’t know how to transition to the next sleep cycle.

We all experience normal, partial arousals in the night. Adults wake 2 to 5 times a night, but because most of us know how to get ourselves back to sleep, we are rarely aware of waking. If a child hasn’t had practice getting from drowsy to asleep on her own, it can become a problem. It isn’t that your baby is waking more often, it’s that she doesn’t have the skills to get back to sleep on her own and is looking for whatever helped her fall asleep at bedtime (nursing, rocking, bouncing, cuddling, or bottle feeding to sleep). These things are known as “sleep props” None of these are a problem in themselves but they can become a problem when used as a vehicle to get baby to sleep at bedtime and back to sleep in the night. If your child needs a prop to go to sleep at night, and back to sleep during the night, the best thing you can do for your child’s sleep is to put her down for bed awake. You don’t have to leave her side, and you can pat, shush, rub her tummy or back, and comfort her if she is crying. She will most likely cry because the “prop” has been taken away, and she is frustrated. She is crying because of the habit change, which is confusing at first, but she will very quickly (usually within that first bedtime without the prop) learn how to go to sleep without it. It will only take a few more times, and some comfort during night waking, for her to be able to sleep without the prop. So basically, put her down for bed awake, and then stay with her. “Ride it out” with her as she learns how to connect the steps to getting herself to sleep. She will learn a new way to sleep and she will start sleeping a solid night, which will be so much better for her.

On a lighter note, the four-month regression doesn’t affect every baby. There are babies whose parents have worked from the beginning to establish healthy sleep habits, and these babies tend to sail right through this time unaffected, or with very little disruption to their sleep. If you are finding that you are struggling through this time right now, or that you never found your way out of it, book a call with me, so that we can talk about your own child’s individual sleep issues. You can also download my free guide, and if you want a customized, gentle plan to solve sleep problems once and for all, you can sign up for my babies package.