The 12-Month Sleep Regression: Understand Causes and Solutions
Key Takeaways
The 12 month sleep regression is temporary and usually lasts 2–6 weeks.
Night wakings and infant wake ups are often due to developmental leaps, teething, or separation anxiety.
Reduction in sleep needs common at their age, so sleep balance may need adjusting
Consistent routines and gentle reassurance help your baby settle.
Bedsharing is ok if it works for you.
Understanding your baby’s developmental changes can make regressions easier to manage.
The 12-Month Sleep Regression
Has your baby been sleeping through the night, then suddenly naps become short, bedtime is a battle, and your baby is back to waking in the middle of the night? The 12 month sleep regression is a common, temporary phase and it is not a reflection of anything you have done wrong.
Let’s talk about why this is happening and how to navigate the changes to keep your baby's sleep schedule as consistent as possible (but don’t worry if it isn’t!).
What Is the 12-Month Sleep Regression?
A sleep regression is a period when a baby’s previously steady sleep pattern changes, often unexpectedly.
Around the 12-month mark, parents may notice:
Shorter or skipped naps
Bedtime battles, resistance to sleep, or other sleep problems
Infant wakes up crying more often
Increased clinginess or separation anxiety
These disruptions are a normal part of development. Your babies' brains are busy mastering new skills, and sometimes that practice happens at night.
What Are Common Sleep Regression Ages?
Babies often experience sleep regressions at predictable stages:
4 months: Circadian rhythm changes
8–10 months: Crawling, standing, and separation anxiety
12 months: Walking, teething, and nap transitions
18 months: Independence and boundary testing
2 years: Language explosion and toddler independence
For more details on each regression stage, see our Sleep Regression vs. Progression post.
How Does a Child’s Sleep Change Around 12 Months?
At this age, sleep patterns naturally shift. Babies often move from 2–1 naps (happens between 12-18months) and wake windows gradually lengthen. Nighttime sleep should consolidate, but regressions can make sleep schedules feel unpredictable.
Mobility, language development, and separation anxiety can all affect how easily a baby settles. Understanding these changes can help parents respond calmly rather than feeling frustrated.
Why the 12-Month Sleep Regression Happens
Several factors contribute to the regression:
Dropping the second nap too early
Many babies still need two naps. Skipping a nap too soon can make it hard to have enough consistent awake time in their day and increase night wakings and sleep issues. See our guide to nap transitions.
Reduction in Sleep Needs
The total amount of sleep they need in 24hrs is only ever decreasing, so if they are not having enough consistent awake time in their day or before naps/bedtime, this can lead to fighting sleep, overnight wakes, split nights or early morning rising
Separation anxiety
Babies become aware when parents leave, which can make bedtime and staying asleep challenging.
Developmental leaps
New skills like walking or talking keep the brain active, sometimes interfering with sleep.
Teething
Discomfort from molars or incisors can make it harder to settle.
Boundary testing
Babies and toddlers begin to explore “no,” which can carry over into naps and bedtime resistance.
These factors are temporary, and understanding them helps parents respond with patience and consistency.
Are Sleep Regressions Based in Science?
Yes. Sleep regressions are a real phenomenon. Research shows that babies experience predictable disruptions at certain developmental milestones. Rapid brain growth, motor skill development, and separation anxiety all contribute to these temporary changes.
Your baby is not being difficult. Their brain is busy learning new skills.
Why Do Babies Wake Up Crying?
Many parents notice that babies wake in the night crying during this regression. Common reasons include:
Transitioning between sleep cycles
Babies’ sleep occurs in cycles of 30–50 minutes. Around 12 months, they may struggle to self-soothe between cycles, leading to night wakings.
Separation anxiety
Babies realize the parent is not nearby and seek comfort.
Developmental bursts or discomfort
Teething, crawling, or walking practice can disrupt sleep.
Crying is a signal that your baby needs reassurance. Responding calmly helps them feel secure and supported.
Is it Teething or Sleep Regression?
It can be difficult to tell the difference. Teething is usually accompanied by drooling (more excessive than normal), swollen gums, chewing, irritability, and some parents have noted fevers when babies teeth.
The differences are subtle so it can be hard to spot. But, if your baby is generally happy during the day and isn't chewing on their hands or toys at a more consistent rate you are likely seeing a sleep regression.
This doesn’t mean you can't have your baby going through their teething and sleep regression at the same time.
Addressing Nighttime Awakenings and Separation Anxiety
Night time wakings are exhausting. As everyone tells you as a parent these are the hardest nights. The best way you can support your baby is to respond calmly and give them reassurance you are there.
Some advice to support a faster return to sleep is to keep the lights dim, keep your voice low and soothing, and for some (not all babies) pat their little bus to help further soothe them.
Not all babies are the same, some will need a pick up and swaddle and some will struggle to go back to sleep if picked up. Find what works best for you in the moment and worry less about the advice and more about what works for your unique situation.
Control Your Calm as a Parent offers strategies to help calm your nerves and keep you feeling in charge of the situation.
Should I let my baby sleep in my bed during a regression?
If bedsharing works for you it is a great strategy to maximise your sleep and that of your child. If you do bedshare. It is normal and natural for our children to want to be close to us, even during sleep. If you do decide to bedshare then ensure that you are following the Safe Sleep Seven https://llli.org/news/the-safe-sleep-seven/
How Long Does Sleep Regression Last?
Parents often ask, “how long does sleep regression last?” Most 12-month regressions last 2–6 weeks. Some babies may take a little longer to adjust, but it is temporary. Consistency and patience help you better navigate this phase and come out with a baby that still sleeps through the night.
Survival Tips for Parents and Babies
Now this is the most important part. Let’s start by saying yes this part is hard. As parents we are made to endure the hard parts. Here are a few tips that help.
Keep routines consistent even when it feels hard
Protect nap times and watch wake windows
Create a calming sleep environment
Respond gently to night wakings and separation anxiety
Take care of yourself and sprinkle humour and patience into the night
Learn more about common baby sleep disruptors
When to Seek Extra Help
Sometimes it’s not just in your head. You may need extra support. The support of your physician, a sleep expert, or even a counsellor. Someone who will listen and support you and your baby.
Consider professional support if:
Sleep regressions last longer than 2 weeks or night wakings are happening more then twice a night
Family wellbeing is affected by stress or exhaustion
Woodlands Collective offers tailored services for families:
Light Sleep Support
One consultation session
Deep Sleep Support
Personalized sleep plan with 4 weeks of follow-up
In-Home Sleep Support
Hands-on guidance for Vancouver-area families
Sleep Encyclopedia Workshop
Did you know? Our sleep services may be covered under your extended health benefits in BC, Ontario, and Alberta.