The 12 Month Sleep Regression: Why Your Baby Stops Sleeping Well Again and What to Do About It

You made it to your baby's first birthday. Sleep has been getting better, you have found a rhythm, and then almost overnight everything changes. Your one year old is waking multiple times again, refusing to settle at bedtime, and clinging to you every time you try to leave the room. If this sounds familiar, there is a very good chance you are in the middle of the 12 month sleep regression.

This post explains what it is, why it happens, how long it lasts, and what you can do to get through it.

What Is the 12 Month Sleep Regression?

A sleep regression is a period when a baby who has been sleeping reasonably well suddenly begins waking more at night, resisting naps, or taking much longer to fall asleep. The 12 month regression is one of the most well known phases in infant sleep development, and it typically arrives somewhere between 10 and 18 months. Not every baby will experience it in the same way, and some may move through this stage with very little disruption at all.

What makes this regression so surprising for many parents is that it often arrives just as sleep has started to feel manageable. Research published in the journal Pediatrics found that around 72 percent of 12 month old babies were sleeping for six or more consecutive hours at night. A regression at this point can feel like a sudden and unwelcome step backwards, even when everything is actually going right developmentally.

Why Does It Happen? The Developmental Changes at One Year Old

The 12 month sleep regression is almost always driven by a combination of major changes happening simultaneously in your baby's brain and body. Understanding what is going on beneath the surface makes the experience feel far less alarming.

New Physical Skills Are Disrupting Sleep

By 12 months, many babies are pulling up to stand, cruising along furniture, and in some cases taking their very first steps. The brain works overtime to wire in these new skills, and this neurological activity does not switch off at bedtime. Babies mastering a major motor milestone often practise it in their sleep, waking themselves in the process. This is actually a sign of healthy development, even when it does not feel that way at three in the morning.

Separation Anxiety Is at Its Peak

One of the biggest drivers of the 12 month regression is separation anxiety, which typically reaches its greatest intensity around the first birthday. Your baby now understands object permanence, meaning they know you continue to exist even when you leave the room. This cognitive leap is healthy and normal, but it also means that your baby is very aware that you are somewhere else when they cannot see you. You may notice your baby cries at the start of the goodnight routine, reaches for you urgently in the cot, or wakes and calls out until you return. Responding with warmth and consistency is the most effective way through this phase.

Teething and Nap Schedule Changes

The 12 month period often coincides with the arrival of the upper lateral incisors and, a little later, the first molars. At the same time, many parents mistake the regression for readiness to drop the second nap. This is one of the most common pitfalls at this age. An overtired 12 month old will sleep worse, not better, and most sleep experts recommend keeping babies on two naps until at least 14 to 15 months. If your baby suddenly refuses a nap, adjust the wake window before it rather than cutting it out entirely.

How to Recognise the Signs

The most common signs of the 12 month sleep regression are frequent night waking after a period of longer, more settled sleep; distress or crying at bedtime when settling had previously been straightforward; calling out when you leave the room at nap time or at night; and taking noticeably longer to fall asleep. Some babies also begin taking longer daytime naps as the body tries to compensate for broken nighttime sleep. If you are seeing several of these signs together and your baby is around the one year mark, a regression is the most likely explanation.

How Long Will It Last?

Most 12 month sleep regressions resolve within two to six weeks. The Sleep Foundation notes that in most cases symptoms do not persist longer than a few weeks, provided parents maintain consistent sleep habits and routines. If sleep disruptions continue beyond six to eight weeks, or are accompanied by other concerns such as unusual breathing, changes in feeding, or poor weight gain, it is worth discussing the situation with your health visitor or paediatrician.

What You Can Do Right Now

There is rarely a single solution, but these strategies are consistently recommended by paediatric sleep experts and can make a real difference during this phase.

Keep Your Bedtime Routine Consistent

A stable and predictable bedtime routine makes it significantly easier for young children to fall and stay asleep. Research published in the journal Sleep found a clear link between a consistent bedtime routine and improved sleep outcomes for babies and toddlers. A warm bath, a quiet feed, a short story, and a calm goodbye ritual signal to your baby's nervous system that it is time to wind down. The specific activities matter less than the fact that they happen in the same order every evening, because predictability is genuinely reassuring for babies whose developmental world is changing fast.

Introduce a Comfort Object

Around 12 months, many babies are ready to form an attachment to a small comfort object such as a soft blanket or gentle plush companion. A familiar object can help your baby feel secure when you are not in the room, giving them something to reach for during the night. Choose something soft, breathable, and appropriate for their age.

The HelloLoomi 2in1 Blanket with Baby Comforter in Dusty Rose combines a soft blanket with a small comforter in one piece, making it easy for your baby to recognise and reach for in the night. For cooler evenings, the HelloLoomi Merino Baby Blanket with Teddy is a wonderful option. Merino wool naturally regulates temperature so your baby stays warm without overheating, and the soft teddy face makes it an appealing companion for babies approaching their first birthday.

Practice Daytime Separations

One of the most effective ways to ease separation anxiety at bedtime is to practise small, manageable separations during the day. Leave the room briefly while your baby plays and return with a warm smile. Let a trusted grandparent or caregiver spend some time alone with your baby. These daytime experiences teach your little one that when you disappear, you always come back, and this understanding gradually reduces the distress at bedtime. When you say goodnight, keep your goodbye warm but brief and confident. A short, cheerful exit is far more reassuring than a hesitant, drawn out departure.

Support Sleep with a Calming Environment

At this age, babies are more aware of their surroundings than ever before. A darkened room, a gentle background sound, and a room temperature between 16 and 20 degrees Celsius all contribute to easier settling. A soft, familiar blanket in the sleeping space can add sensory comfort that helps your baby feel at ease. The HelloLoomi Soft Muslin Cotton Blanket in Ivory White is made from breathable organic cotton and is gentle enough for sensitive baby skin.

A Reminder for Exhausted Parents

Living through a sleep regression when you are already sleep deprived is genuinely hard. If you have a partner, share the nighttime settling as fairly as you can. If you are doing it alone, reach out to family or friends for some daytime rest. The 12 month regression is temporary, even when it does not feel that way at four in the morning.

This phase is not a sign that anything has gone wrong. It is a sign that your baby is growing and developing exactly as they should. With a consistent routine, a calm environment, and the right comfort essentials, most families find their way through within a few weeks.

At HelloLoomi, we create soft, sustainable baby essentials designed to support your whole family through every stage of the early years. Browse our collection and find the gentle comfort your baby deserves.

Frequently Asked Questions

How do I know if my baby is going through the 12 month sleep regression or just having a bad week?

The 12 month regression involves a consistent shift from previously settled sleep to frequent night waking, strong bedtime resistance, and increased daytime clinginess lasting more than a few nights. If your baby has been sleeping well and suddenly struggles for five or more consecutive nights, a regression is the most likely cause. A genuine regression affects both naps and nights, which distinguishes it from a shorter disruption caused by illness or a routine change.

Should I drop to one nap during the 12 month sleep regression?

In most cases, no. The regression is frequently mistaken for readiness to move from two naps to one, but dropping the second nap too early almost always makes sleep worse. Most paediatric sleep experts recommend keeping babies on two naps until at least 14 to 15 months. If your baby resists a nap during the regression, try shortening the wake window before it rather than cutting the nap entirely.

How long does the 12 month sleep regression last?

For most babies, the 12 month regression lasts between two and six weeks. The Sleep Foundation notes that symptoms typically resolve within a few weeks when parents maintain consistent habits and routines. If disruptions continue beyond six to eight weeks, or are accompanied by changes in breathing, feeding, or growth, speak with your paediatrician.

What is a good comfort object for a baby going through the 12 month sleep regression?

At 12 months, babies are developmentally ready to attach to a small comfort object. A breathable muslin blanket, a soft merino wool blanket with an animal face, or a combined blanket and comforter are all good choices. Choose something made from natural fabric, free from small parts, and safe in the cot. The HelloLoomi 2in1 Blanket with Baby Comforter and the Merino Baby Blanket with Teddy are both designed with this age in mind.

Is it normal for a 12 month old to suddenly start waking at night after sleeping through?

Yes, and it is almost always temporary. Babies who have been sleeping through the night can experience setbacks throughout the first two years, often linked to developmental leaps, teething, or changes in routine. The 12 month mark is one of the most predictable periods for this kind of disruption because separation anxiety, new motor skills, and rapid cognitive growth are all happening at once.

Will my usual settling strategies still work during the 12 month sleep regression?

Many parents find that approaches that worked before, such as a consistent goodbye ritual and a familiar comfort object, remain effective during the regression when applied consistently. Avoid changing too many things at once. Focus on maintaining your existing routine and responding with warmth, and hold off on any major structural changes to sleep habits until the regression has passed.

When should I be worried about my baby's sleep problems at 12 months?

Most disruptions at 12 months are normal and resolve without medical intervention. Speak to your health visitor or paediatrician if problems last longer than six to eight weeks without improvement, if your baby shows unusual breathing or snoring during sleep, if there are changes in feeding or growth, or if your baby seems in genuine physical pain. Your instincts as a parent are always worth acting on.