12-Month Sleep Regression
Medically reviewed by Dr. Sarah Chen, MD, FAAP · Board-Certified Pediatrician
Content reviewed against published AAP, AAP, NIH guidelines
Last reviewed:
Sleep concerns affect nearly every family at some point. When it comes to 12-month sleep regression, here is what the guidelines recommend.
The short answer
The 12-month sleep regression is driven by major developmental changes - many babies are learning to walk, experiencing separation anxiety, and developing a stronger will. Your baby may start fighting bedtime, waking more at night, refusing naps, or waking earlier than usual. This regression typically lasts 2-6 weeks. The most common mistake is dropping to one nap too early - most 12-month-olds still need two naps. Maintain consistent routines and this phase will pass.
Key takeaways
- The 12-month sleep regression is driven by major developmental changes - many babies are learning to walk, experiencing separation anxiety, and developing a stronger will. Your baby may start fighting bedtime, waking more at night, refusing naps, or waking earlier than usual. This regression typically lasts 2-6 weeks. The most common mistake is dropping to one nap too early - most 12-month-olds still need two naps. Maintain consistent routines and this phase will pass.
- Usually normal when: Your 12-month-old was sleeping well and suddenly started waking at night or fighting sleep
- Call your doctor if: Your baby has stopped breathing during sleep or has turned blue
- Varies by age — see the age-by-age breakdown below
“To reduce the risk of sleep-related infant deaths, the AAP recommends that infants sleep on their backs, on a firm, flat surface, without any soft bedding.”
Parents everywhere have the same worry. You are doing the right thing by looking into it.
What Parents Should Know
According to AAP, NIH guidelines, the 12-month sleep regression is driven by major developmental changes - many babies are learning to walk, experiencing separation anxiety, and developing a stronger will. Your baby may start fighting bedtime, waking more at night, refusing naps, or waking earlier than usual. This regression typically lasts 2-6 weeks. The most common mistake is dropping to one nap too early - most 12-month-olds still need two naps. Maintain consistent routines and this phase will pass. At 11-12 months, the regression often begins around 11-12 months as babies approach their first birthday. They may be pulling up to stand in the crib, cruising, or taking first steps. These exciting motor milestones make it hard to settle down. Your baby might stand in the crib and cry instead of lying down. Separation anxiety also peaks around this time, making it harder for baby to let you leave the room. Practice the new motor skills during the day so they are less compelling at night. It is generally considered normal when your 12-month-old was sleeping well and suddenly started waking at night or fighting sleep. However, you should contact your pediatrician promptly if your baby has stopped breathing during sleep or has turned blue.
Normal vs. Concerning
By Age
What to expect by age
11-12 months
The regression often begins around 11-12 months as babies approach their first birthday. They may be pulling up to stand in the crib, cruising, or taking first steps. These exciting motor milestones make it hard to settle down. Your baby might stand in the crib and cry instead of lying down. Separation anxiety also peaks around this time, making it harder for baby to let you leave the room. Practice the new motor skills during the day so they are less compelling at night.
12-13 months
This is the heart of the regression. Common symptoms include: refusing one or both naps, taking much longer to fall asleep at bedtime, waking 1-3 times at night when they previously slept through, and early morning waking. Many parents assume this means it is time to drop to one nap, but this usually makes things worse. Most babies are not ready for one nap until 14-18 months. Keep offering two naps and push through. The regression is temporary.
13-14 months
Most babies come through the regression by 13-14 months and return to their previous sleep patterns if parents maintained consistent routines. If sleep has not improved after 6 weeks, reassess the schedule - ensure wake windows are appropriate (about 3-4 hours between sleeps) and bedtime is not too late. If your baby seems to genuinely not need two naps anymore (consistently taking 30+ minutes to fall asleep for the second nap), it may be time to cautiously trial one nap.
What to Tell Your Pediatrician
- Describe when you first noticed 12-month sleep regression and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if sleep disruption has lasted more than 6 weeks without any improvement.
- Mention if your baby seems to be in pain when lying down (pulling at ears, arching back) suggesting possible illness.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Your 12-month-old was sleeping well and suddenly started waking at night or fighting sleep
- The sleep disruption coincides with learning to walk, talk, or other developmental milestones
- Your baby is otherwise healthy, eating well, and developing normally
- Sleep disruption lasts 2-6 weeks and then gradually improves
- Sleep disruption has lasted more than 6 weeks without any improvement
- Your baby seems to be in pain when lying down (pulling at ears, arching back) suggesting possible illness
- Your baby is snoring, mouth breathing, or having pauses in breathing during sleep
- Chronic sleep deprivation is significantly affecting your or your baby's daily functioning
- Your baby has stopped breathing during sleep or has turned blue
- Your baby is extremely lethargic, unable to wake fully, or has a high fever alongside the sleep changes
What You Can Do at Home
- Keep track of when you notice 12-month sleep regression — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that your 12-month-old was sleeping well and suddenly started waking at night or fighting sleep — this is generally within the range of normal.
- At 11-12 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Maintain a consistent bedtime routine. Keep the sleep environment cool, dark, and quiet.
- While monitoring at home, seek immediate care if your baby has stopped breathing during sleep or has turned blue.
Related Conditions
8-Month Sleep Regression
The 8-month sleep regression is usually driven by major developmental leaps in mobility, cognition, and attachment. Your baby is learning to sit, crawl, pull up, and is developing object permanence and separation anxiety. These exciting milestones can temporarily disrupt sleep, but most babies settle within 2-4 weeks.
18-Month Sleep Regression
The 18-month sleep regression is driven by explosive language development, increasing independence, separation anxiety resurgence, and possibly the transition from two naps to one. Your toddler's vivid imagination may also lead to new nighttime fears. This phase typically lasts 2-6 weeks with consistent routines.
Baby Separation Anxiety
Separation anxiety is a completely healthy sign that your baby has formed a strong attachment to you. It typically begins around 6-8 months, peaks between 10-18 months, and gradually eases by age 2-3. It means your baby's brain has developed enough to understand that you exist even when they cannot see you, but not yet enough to understand that you will always come back.
Dropping from Two Naps to One
Most babies transition from two naps to one between 12-18 months. Signs include consistently fighting or skipping the second nap, taking very long to fall asleep for naps, or bedtime becoming a battle. The transition usually takes 2-4 weeks and some crankiness is normal during the adjustment.
Related Resources
Milestone Checklists by Age
Track your baby's developmental milestones from birth to 5 years with age-specific checklists.
Baby Sleep Guide
Age-by-age sleep needs, schedules, and evidence-based sleep strategies.
Month-by-Month Development
Detailed monthly development guides from birth through 24 months.
When to Call the Doctor
General guide on when to call the pediatrician, visit urgent care, or go to the ER.
Frequently asked questions
Is 12-month sleep regression normal?
When should I call the doctor about 12-month sleep regression?
When is 12-month sleep regression normal?
What causes 12-month sleep regression?
What should I mention to my pediatrician about 12-month sleep regression?
Is 12-month sleep regression normal at 11-12 months?
Is 12-month sleep regression normal at 12-13 months?
Should I go to the ER for 12-month sleep regression?
Does 12-month sleep regression go away on its own?
References
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss 12-Month Sleep Regression.
Things to mention
- Describe when you first noticed 12-month sleep regression and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if sleep disruption has lasted more than 6 weeks without any improvement.
- Mention if your baby seems to be in pain when lying down (pulling at ears, arching back) suggesting possible illness.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- Sleep disruption has lasted more than 6 weeks without any improvement
- Your baby seems to be in pain when lying down (pulling at ears, arching back) suggesting possible illness
- Your baby is snoring, mouth breathing, or having pauses in breathing during sleep
Urgent signs to report immediately
- Your baby has stopped breathing during sleep or has turned blue
- Your baby is extremely lethargic, unable to wake fully, or has a high fever alongside the sleep changes
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of 12-month sleep regression are normal. Talk to your pediatrician if your baby has stopped breathing during sleep or has turned blue.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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Related Sleep Concerns
8-Month Sleep Regression
The 8-month sleep regression is usually driven by major developmental leaps in mobility, cognition, and attachment. Your baby is learning to sit, crawl, pull up, and is developing object permanence and separation anxiety. These exciting milestones can temporarily disrupt sleep, but most babies settle within 2-4 weeks.
18-Month Sleep Regression
The 18-month sleep regression is driven by explosive language development, increasing independence, separation anxiety resurgence, and possibly the transition from two naps to one. Your toddler's vivid imagination may also lead to new nighttime fears. This phase typically lasts 2-6 weeks with consistent routines.
Baby Separation Anxiety
Separation anxiety is a completely healthy sign that your baby has formed a strong attachment to you. It typically begins around 6-8 months, peaks between 10-18 months, and gradually eases by age 2-3. It means your baby's brain has developed enough to understand that you exist even when they cannot see you, but not yet enough to understand that you will always come back.
Dropping from Two Naps to One
Most babies transition from two naps to one between 12-18 months. Signs include consistently fighting or skipping the second nap, taking very long to fall asleep for naps, or bedtime becoming a battle. The transition usually takes 2-4 weeks and some crankiness is normal during the adjustment.
How Long Should Baby Be Awake Between Naps?
The ideal awake time between naps (called a "wake window") increases as your baby grows. Newborns may only handle 45-90 minutes awake, while toddlers can manage 4-6 hours. Getting wake windows right is one of the most effective ways to improve nap quality, because both too-short and too-long wake times lead to poor sleep.
Is a Bath Before Bed Really Necessary?
A nightly bath is not medically necessary and some babies with sensitive skin do better with less frequent bathing. However, a warm bath can be a powerful sleep cue because the subsequent body temperature drop triggers melatonin production. If you include a bath, keep it calm and warm rather than stimulating.