Even if you don't know what it's like to be a brand-new parent, you at least know that sleep can be hard to come by. As parents and baby settle into their new routine, sleep might (mercifully) come more frequently and with greater ease. Then, all of a sudden, your baby who once slept like a little angel, is up much of the night, upset and overtired. What happened when your baby hit 4 months of age that affected her sleep? What is the 4-month sleep regression anyway?
The first thing to know is that your baby will sleep again at some point (I don't know personally, but I'd guess that that is a real fear because it would be for me). Simply put, a sleep regression is when your baby fights sleep and wakes frequently, according to the website for Wee Bee Dreaming pediatric sleep consulting. It's not uncommon for babies (and, by extension, caregivers) to experience regressions around 4 or 5 months of age. The 4-month sleep regression can be brutal, especially if your baby slept well before. According to The Baby Sleep Site, the 4-month sleep regression is actually a permanent change in your baby's sleeping habits. Your baby may no longer have the ability to sleep anywhere at any time, because her brain is maturing and she's developing the ability to cycle through different types of sleep, rather than staying in deep sleep for an extended period of time.
When babies are in a cycle of light sleep, they wake more easily, according to the website for The Baby Sleep Geek. This development can be problematic when it comes to trying to lull your baby to sleep. Additionally, as she begins to cycle between light and deep sleep, it may be difficult for her to close her eyes and fall back asleep as adults do. That transition can be especially hard if she doesn't yet have a lot of experience falling asleep on her own, as noted in the aforementioned post on the website for The Baby Sleep Geek. If you place her in her crib while she's in a light sleep stage — or she wakes up in the middle of the night — she may struggle to get herself back to sleep. As she grows, she will be able to better regulate these disturbances.
Also around 4 to 6 months of age, you may notice your baby begin to roll around. This is typical, but, according to the previously-mentioned post on the Wee Bee Dreaming website, rolling makes swaddling during sleep unsafe. The transition from a swaddle to a sleep sack — a common next step before blankets are acceptable — can also cause your baby to be more susceptible to nighttime wake-ups while in lighter sleep stages.
Developmentally, your baby is experiencing a lot around this age, as she begins to interact with the world around her. There are a lot of changes and, according to Today's Parent, it's important to help your baby adapt to permanent changes to survive a sleep regression. Developing a nighttime routine and reinforcing it consistently can help solidify healthy sleep habits that not only will carry you through the 4-month sleep regression, but also help your baby as she continues to grow. Remember, the changes in her sleep taking place at 4 months of age are permanent, so she'll need to be able to handle them long-term. According to the aforementioned post on the Wee Bee Dreaming website, moving a baby's bedtime up earlier may also help at this age because she's often taking fewer naps now. Letting her nap too late in the day can push bedtime back as well, complicating matters and resulting in wonky nighttime sleeping.
Also important to note: the previously-mentioned article from The Baby Sleep Site recommends using sleep training methods as a way to teach your baby how to fall asleep on her own during and after the 4-month sleep regression. Although it may not be right for every family, if you're going to try it, make sure to hold off on sleep training so that the 4-month sleep regression doesn't set back your progress.
The 4-month sleep regression can be a doozy, but if you know what's happening, you'll hopefully have an easier time surviving it. Your little one is growing every day and with the right assistance, she'll be sleeping peacefully once again soon.