Dr. Sarah Mitchell
About Author

15 Month Sleep Regression: Teething, motor leaps  and testing boundaries [Complete Guide]

The 15 month sleep regression is associated with teething, motor leaps  and testing boundaries as your child becomes more communicative and mobile.  

What is a sleep regression? 

Anytime you hear sleep regression, think growth and distraction.  Your little one is growing physically or neurologically and that is distracting them from relaxing down into sleep. 

What are the signs of a sleep regression? 

  1. Bedtime resistance:  more resistance and more time to fall asleep where your baby was previously going down fine.  Your child might want you to sit in the room while they fall asleep.

  2. Increased night waking.

  3. Shorter naps where your baby was napping for an hour or longer.

  4. Early morning wake ups such as 5 or 5:30 am where your baby previously made it to 6 am.

What are the Causes of the 15 Month Sleep Regression:

  1. Teething - 1st molars
  2. Motor Leap: Mastering walking 
  3. Testing Boundaries

What are Signs of Molars Coming Through? 

  1. Some babies might want to breastfeed more.  Less commonly is babies wanting to eat less. Some babies are less interested in food in general. 
  1. Some babies might tug on their ear or rub their faces.  Others present with having one finger in the mouth at bedtime, where seemingly unbothered by teething during the day.

The pain with teething occurs before the teeth have cut through the gums.  Once you can see the teeth the pain has receded.  So teething is often a hind sight diagnosis of what’s been happening.   For one tooth coming through it could take 1 to 2 weeks for that tooth to protrude once you have the first signs of teething pain.  During that time the pain might ebb and flow.  You might have a terrible day but then have a fine day the next day.  This can be very confusing to parents, but is completely normal.   If one tooth takes 1 to 2 weeks you can imagine that if you have multiple teeth erupting this could take even longer!  Many parents report 4 week of on and off disrupted sleep and the most common sign with teething is 5 am wake ups.  Your baby surfaces from a sleep cycle and is then distracted by the discomfort in her gums and can’t relax back down into sleep. 

This chart from the American Dental Society shows the average ages of tooth eruptions.

What are the signs of the Motor Leap Sleep Regression at 15 Months? 

15 months is the average age that most kids start to walk.  Often a motor leap interrupts night time sleep and manifests in your baby being awake in the night, but content.  Often a parent looks over and sees their baby lying in their crib happily in the middle of the night. 

A motor leap can also present as a 5 am wake up.  Your baby surfaces from a sleep cycle and then starts thinking about that cool new motor skill and doesn’t relax back down in the next sleep cycle.

What are the Signs of Testing Boundaries in the 15 Month Sleep Regression? 

Erik Erickson is a psychosocial development researcher.  He “maintained that personality develops in a predetermined order through eight stages of psychosocial development, from infancy to adulthood. During each stage, the person experiences a psychosocial crisis which could have a positive or negative outcome for personality development.”

In his theories he claims that the Autonomy vs Shame period starts at 1.5 years of age.  I believe it can start a little earlier around 15 months.  I work with many strong willed toddlers who have decided they want their parents to sit beside them or in their room or to be patting their back at bedtime to fall asleep. This occurs even though they were previously sleeping well independently.  So why the change?  Why not?  They are exerting their opinion on the world and seeing what comes back.  Testing boundaries. I go into more detail about this on this Toddler Sleep Regression Blog post.  

How Long Does the 15 Month Sleep Regression Last? 

How intensely a child feels a sleep regression and how long it lasts is related to the cause of the regression and a child’s temperament.  Some kids are more flexible than others whereas some kids feel things more intensely and are more determined to have you sit beside them while they fall asleep. 

What Can You Do To Ease the 15 Month Sleep Regression? 

Just because your baby is distracted at sleep time, it doesn’t mean that they are not capable. Continue with your bedtime and nap time routines but offer more attention as needed.  Consider the root cause of the regression.  How can you help distract your child from what’s distracting them?    Can you offer any pain relief before naps or at 3 am to help with those early wake ups?   You’ll likely want to offer more comfort to your child in the night to help distract them from what’s distracting them.  Rocking back to sleep or patting back to sleep can be helpful.  

If testing boundaries is the cause, the best approach is to acknowledge the demand and offer a little win.  “Yes, I know you would like Mommy to sit here while you go to sleep, but I have to go do the dishes.  Would you like it if I come back and check on you in 5 minutes?”  

Or perhaps you do sit there until your baby falls asleep but be prepared to do that every night from here on in.  Could you provide a little win instead, and say “I can see you want more company tonight.  I can sit here for 5 minutes and then I have to go do the dishes, would you like that?” Just be prepared for a protest when you leave the room.

What NOT to Do at the 15 Month Sleep Regression

  1.  Don’t move your child out of the crib into a bed thinking that will resolve the issue.  Most kids aren’t ready for a big bed until age 2.5 and making the move now will force you to lie beside your toddler to get them to fall asleep opening a whole new can of worms.

  2. Don’t completely ignore your little one and close the door and not return.  Imagine the world from your little person's perspective.  They are working on some new concepts and are testing those out.  I feel you should be acknowledging them calmly and compassionately, but at the same time being communicative on how you are doing to respond and then following through.  It’s the grey area in your response that keeps the behavior going.  When parents respond in a variety of ways to the protest, the child isn’t sure what to expect and the behavior continues.  Be calm, communicative, compassionate and consistent and this too shall pass.


Sleep regressions can happen at any age if your child is growing physically or neurological and is distracted.  Try to address the root cause to eliminate what is distracting them.  Stick to your regular routines and timing.  Know that this too shall pass eventually. 

If you’re struggling with sleep but it’s not a regression, or you’re not sure if it’s a regression, take our simple 6 question sleep quiz to find out WHY your baby keeps waking up at night.

More Posts

You Might Also Like

Read More

Colic in Babies: Baby Massage and Other Tactics for Quick Relief

Colic by definition is more than three hours of crying per day, for more than three days a week, for more than three weeks. Researchers actually don't know the root cause however there are many working theories. Find more about Colic in Babies and its remedies.
May 2, 2022
Dr. Sarah Mitchell
Read More
Sleep Teaching

What is Cry It Out Sleep Training Method: Does It Work?

People have wildly different definitions of what cry it out means to them. For some people, cry it out means tears of any kind. But the true definition of cry it out, cried out, means extinction.
Apr 10, 2022
Dr. Sarah Mitchell
Read More

Nursing Baby To Sleep: Is It Good or Bad?

Nursing to sleep: is it bad? or For some people, they can nurse to sleep and have these beautiful, long stretches of nighttime sleep. Why is that?
Apr 9, 2022