Have you heard of split nights? Or, even more, experiencing split nights in your home?
More formally it might be called segmented sleep or biphasic sleep, and it is actually not the same thing as a little one waking in the middle of the night. A middle of the night wake up might look like a cranky/fussy baby needing some comfort or assistance getting back to sleep. As frustrating as those are, there is often a successful “fix” (such as rocking or nursing back to sleep). But a split night is more like a 2:00 am dance party! It describes a situation where your little one sleeps for a long stretch, then wakes up happy and energetic in the middle of the night, and stays that way for an hour or more.
And split nights are actually not “new” to most cultures. In pre-industrial times (before the widespread use of the electric light bulb) it was actually considered normal for most people to get up for a couple of hours in the middle of the night. These hours consisted of social activities like playing, visiting neighbors, having sex, praying, and reading. Then they would go back to sleep until the morning time.
However, the majority of our current western society now follows the expectation of closing our eyes at night and sleep straight through until the morning. Except … some of our little ones don’t always get the same memo. And, when they party-hardy throughout the 2:00 am and 3:00 am hours, they are oblivious to the miserable day they are setting their parents up for.
So let’s take a quick look at why this happens and then we’ll get to how to solve the problem.
There are two major drivers when it comes to sleep. There’s our circadian rhythm, which is our natural tendency to fall asleep when it’s dark and wake up when it’s light, and then there’s our homeostatic sleep drive, commonly known as sleep pressure, which builds up over the time we’re awake.
So ideally, over the course of the day, sleep pressure builds up, then at bedtime, when the pressure hits the sweet spot, baby puts her head down and goes to sleep. As that sleep pressure begins to subside, circadian rhythm takes over and baby stays asleep until morning.
In the case of a split night, we could be looking at one of two reasons why they’re waking up.
- Baby’s not getting to bed early enough, OR…
- Baby’s going to bed too early.
Now before you pitch your phone out the window at that seemingly paradoxical explanation, check this out.
If baby’s getting to bed too late, if too much sleep pressure has built up, the brain has this instinctive response that says, “Hey, you’re tired but you’re not sleeping. I’m guessing that’s because there’s a carnivorous apex predator around, so we’d better get ready to make a break for it,” and then starts upping the cortisol levels.
The brain means well, but it’s a little behind the times on our need for lion alerts.
So this can make it tough for baby to get to sleep at bedtime, since that cortisol’s got them a little bit jacked, and it can also cause a full wake up at the end of a sleep cycle, which commonly happens around 2 or 3 in the morning. Ugh.
If this is the case, you’re one of the lucky ones. Treat this like any other night time wake up, reassure baby that it’s still bedtime, comfort her and let her get back to sleep on her own, and consider moving bedtime up a bit over the course of a few nights.
But then there’s the alternate scenario. What if baby’s getting to bed too early.
In a situation where baby’s getting lots of quality daytime sleep and going to bed early, it’s possible that there’s not enough sleep pressure built up to keep baby sleeping until their circadian rhythm takes over and helps them sleep through the rest of the night, so up they get. And now that there isn’t as much sleep pressure, and their circadian rhythm doesn’t have the horsepower to get them to sleep on their own, suddenly they’re up and active for an hour (or three!) while that pressure builds back up.
Now, I’m a HUGE fan of early bedtimes. Over-tiredness is often a much bigger problem than under-tiredness, and many sleep struggles can often be addressed with a slightly earlier bedtime. But, if there is a true split-night situation going on, then it’s worth considering moving bedtime later. This adjustment can help ensure that you are helping your baby hit the optimum sleep pressure right at the same time that baby is going bed for the night.
So my suggestion is to avoid putting baby to bed early more than once or twice in a row. Those times might be when there has been a day of lousy naps when your little one is clearly overitred long before bedtime. And a tough day like that will likely build up necessary sleep pressure already. Then try to get back onto her regular schedule starting with her wake-up time the very next morning.
I know that this can all start to sound like an immaculately choreographed ballet, which can also become a bit overwhelming. There are many nuances to understand and they can come across as pretty complicated but also minor adjustments. But trying to understand how they can possibly impact sleep is going to be your best way to address any regressions, setbacks, and interruptions.
One final thing to consider if you’re getting ready to tackle this situation. This is not likely to be an overnight fix. Once baby has gotten into this habit, getting them out of it can take some time. Like any attachment or dependency, overcoming it is an incremental process and it’s likely to meet with some pushback, so if and when things get tough, remember your goal. You’re giving your little one the skills they need to sleep soundly through the night, and that contributes to their well-being in so many different ways. Stay consistent, be patient, and before too long your baby and you will both be enjoying full nights of deep, restful sleep.
