4 Common Causes of Split Nights and How to Fix Them

One of the most common (and exhaustive) sleep struggles I help my clients work through is split nights.

A split night is an extended waking in the middle of the night that happens when your baby's circadian rhythm (the internal body clock) and homeostatic sleep drive (the natural sleep pressure) are out of sync. 

Simply put, your little one’s sleep cycles aren’t aligned for consolidated nighttime sleep, so they’re wide-eyed and ready to play in the middle of the night. Something every tired mama wants to avoid.

So let’s go over some common causes of split nights and how you can get your baby’s sleep back on schedule.

Are split nights a sleep regression?

Split nights aren’t technically a sleep regression, but they can show up during one. 

A split night is usually a schedule issue of too much sleep during the day and not enough sleep pressure at night, which causes your baby to wide awake in the middle of the night.

Sleep regressions are caused by developmental changes, the 4 month mark being the most talked about, that temporarily disrupt normal sleep patterns.

Sleep regressions sometimes trigger split nights because your baby’s sleep needs and rhythms are changing.

4 Causes of Split Nights

While split nights are most commonly caused by a daytime sleep imbalance, here are four reasons why your baby may be struggling with these middle-of-the-night wake-ups:

1. Too Much Daytime Sleep/Bedtime Too Early

The first question we need to ask: Is your baby taking too long of a nap throughout the day? 

While daytime sleep is essential, too much can interfere with your baby’s ability to sleep through the night. Your baby only needs a certain amount of sleep in a 24-hour cycle, so pay attention to the synergy between daytime and nighttime sleep. 

If your baby is maxing out on daytime sleep, they may simply not have enough sleep pressure to stay asleep during the night. On the same note, if bedtime is too early, you’ll run into the same problem.

2. Nap Transitions

The second question we need to ask: Is your baby ready to drop a nap? 

As babies grow, their sleep needs change. They need less sleep and more awake time to be ready to sleep. If your baby takes too many naps and doesn’t have enough awake time during the day, nighttime sleep can be a challenge. 

3. Not Enough Sensory Input

The third question: Is your baby getting enough stimulation during the day?

Babies need sensory input and stimulation to be ready for sleep. Making room for things like tummy time, walks, and gross motor play will support consolidated nighttime sleep. 

4. Inconsistent Morning Rise

And the fourth question: Do you wake your baby up at the same time every day? 

Consistency helps regulate your baby’s internal clock. If your baby’s start to the day fluctuates, it can confuse their circadian rhythm and lead to unpredictable nighttime sleep. 

Most importantly, if your baby is experiencing extended night wakings, letting them sleep later into the morning will only reinforce their wakefulness at night. 

Bonus: Can split nights be caused by hunger?

Sometimes, but not usually. If your baby genuinely needs nighttime calories, they may wake for a feed then struggle to fall back to sleep if they’re unsatisfied.

Most split nights are caused by schedule imbalances rather than hunger. If your baby is eating well during the day and still having long wake windows at night, it’s usually a sign to adjust their routine rather than add more feeds.

How can I fix a split night?

If your baby is experiencing a split night, it’s important to remember that the night needs to shrink before it can extend again. This process requires patience and may take several days to a couple of weeks as you reset your baby’s circadian rhythm.

Here’s how you can get started.

Decode the root cause.

Whether it’s too much daytime sleep, undertiredness, overtiredness, or a schedule misalignment, understanding the root cause of split nights helps you adjust your baby’s routine in a way that supports longer nighttime sleep. 

Make necessary changes.

For most children, the answer is found in better aligning their nap schedule, typically waking them up earlier in the morning and capping daytime sleep. The goal here is to avoid letting them sleep after being awake at night or starting the day on time to avoid letting them sleep in and creating a cycle. Don’t worry—you won’t be waking up early forever!

Consolidate nights.

Observe patterns for 7-10 days before making a call about what’s working or not working. Make one or two changes at a time so you can easily determine what’s working and what’s not. 

If the split night doesn’t improve after a few days, it’s worth revisiting your baby’s sleep needs or looking at sleep through a wider lens.

How Much Sleep Do Babies Need?

Remember, infants between 4-11 months need an average of 12-15 hours of sleep within a 24-hour period. If you’re hoping for 10-12 hours of sleep overnight, you may need to adjust their nap schedule accordingly. 

As your baby approaches their first birthday and enters toddlerhood, the transition to one nap is on the horizon. This transition can sometimes help with issues like split nights, as your little one will have more awake time to build sleep pressure before bed.

By carefully adjusting the timing of sleep, you can help your baby transition away from split nights and enjoy a restful night’s sleep. 

It might require some extra patience (and extra caffeine), but it’s so worth it for those long nights of deep sleep for your baby AND you.

A Better Night’s Sleep Starts with the Right Schedule

Addressing your baby’s and your entire family’s sleep needs is no small feat, and after a full day of parenting, you deserve to kick back and relax with the peace and assurance that your baby will sleep all night long.

If you’re entering the evening shift with dread instead of a glass of orange wine, it might be time for some extra support…

Ready to say goodbye to feeling frustrated with yourself for feeling frustrated with your baby’s sleep? Work with Ella to get everyone sleeping through the night again! 

To better sleep,

Ella