(Revised and updated from an earlier version)
Early-morning waking is a common problem for babies and toddlers. Unfortunately, early waking is one of the hardest problems to fix because the circadian rhythm resets to light exposure each morning, and even a little light in the morning will cause your baby to ‘lock in’ to an early wake time. In addition, sleep is light in the early morning, so your baby may have difficulty going back to sleep even if he/she needs more sleep. If you search for advice on the topic, you’ll inevitably hear simplistic advice like ‘put him down early for bed’ or ‘put her down later for bed.’ Sometimes a simple change will work temporarily, but if your baby’s sleep pattern is stuck too early, then you’ll need to adjust his/her circadian rhythm in order to achieve a permanently later wake time.
The Science Behind Early Waking in Babies
The drive to sleep is coordinated by two things: homeostatic sleep pressure, which is the build-up of sleep need (sleepiness) over time, and the circadian rhythm. The circadian rhythm is your internal biological clock; it controls the timing of many events in your child’s body, including your child’s biological bedtime and biological wake time. Your child’s biological bed and wake times are bookended by a strong drive to be awake. This means that putting your baby down early may backfire and doing sleep training past a certain time in the morning may be pointless. It’s really important to understand how the circadian rhythm works in order to make sure that you are asking your baby to sleep when he/she is capable of sleeping.
Why would the circadian rhythm promote waking up so early? The answer is light exposure. Our circadian rhythms are designed to reset to light exposure, and our bodies look for the dawn signal in the morning. This means that just a tiny change in the lighting in your baby’s room may lead to a ‘locked-in’ early waking. It’s important to note that it’s not the light itself that will wake your baby up; it’s that if your baby wakes up early for any reason and sees light, his/her body will immediately start to change in response to the light exposure and promote the drive to wake up at that earlier time the next day. The major problem here is that you can’t just make it dark the next day and expect your baby to sleep later; it’s the same thing that happens in jet lag. Since light today leads to an early waking tomorrow, your baby will still wake up early the next day even though you may have taken steps to darken the room.
All that said, sometimes an early-morning waking is not due to the circadian drive to be awake. Since early waking means that your baby might have just had 8, 9 or 10 hours of sleep, her homeostatic sleep drive will be restored and she won’t feel that same pressure to sleep as she did earlier in the night. This will make it really hard for your baby to fall back to sleep. Similarly, sleep is very light in the early morning hours, so it’s easy to wake up to a very soft noise or due to a little tummy rumble or wet diaper. All of these things can prevent your child from sleeping in later even when she is capable of sleeping later.
Need More Help?
We offer several options for optimizing your child's sleep:
SLEEP TRAINING CLASS (for well babies 6-15 months)
PHONE CONSULTATIONS (with one of our sleep experts)
THE SECRET TO NAPS (downloadable e-book)
How can I fix my child’s early waking?
First, you need to figure out the source of the problem by answering these questions:
Does your baby have a sleep association and wake frequently during the night?
If so, do not work on early waking until you address the sleep association. See our blogs on sleep associations or use our sleep training class to create a plan that will help your little one connect sleep cycles through the night.
Is your baby waking for a reason?
If your baby already knows how to fall asleep independently and an early-morning waking for food or comfort is the only problem, then you may not need to shift his/her circadian rhythm. Sometimes sleep associations can linger in the early morning hours long after sleep training. Since sleep is light in the early morning, your baby will be more sensitive to a tummy rumble or the cat roaming the halls. If you are feeding your baby and she is not going back to sleep in the crib but will sleep in your arms, then she has the capacity to sleep later, and sleep training should fix the early waking. Stated a different way, if your baby can sleep under certain conditions, but not in the crib, then she doesn’t have a circadian-misalignment issue, but rather a sleep association. If your baby is used to eating in the early morning and you think she doesn’t need to a