How long should sleep sacks be used?

Sleep sacks, also known as wearable blankets or baby sleeping bags, are wearable blankets used for infants up to around 2 years old. They are an alternative to loose blankets in the crib, providing warmth while reducing the risks associated with loose bedding. Sleep sacks come in different sizes based on the weight and height of the baby. They are designed to fit snugly around the body and have arm holes or sleeves so baby has free movement of their arms and access to their hands for self-soothing.

Many parents wonder how long they should continue to use a sleep sack before transitioning to a loose blanket. There is no set rule on when to stop using a sleep sack, but there are some general guidelines based on baby’s development and sleep safety recommendations. Here is an overview of how long sleep sacks are typically used and what factors to consider when deciding when to transition out of a sleep sack.

Recommended Age Ranges for Sleep Sacks

Most sleep sack manufacturers provide a recommended age range for their products, usually spanning from newborn to around 18-24 months. Here are some general guidelines on appropriate age ranges for different types of sleep sacks:

– Newborn sleep sacks: Recommended from birth to 3-6 months. These have an adjustable width to snugly fit young infants.

– Transitional sleep sacks: Recommended from 6-18 months. These have RoomToGrow features like extra foot room and can adapt as baby grows.

– Toddler sleep sacks: Recommended from 18-36 months. These are made with wearable blanket material to keep older babies warm.

So in general, sleep sacks are commonly used up to age 2. However, every baby develops at their own pace, so the decision on when to stop using a sleep sack depends on other factors as well.

When Baby Can Roll Over or Stand

Once baby can roll over or pull themselves up to stand in the crib, it’s time to transition out of the sleep sack. At this point, the sleep sack could potentially pose a danger:

– Rolling risk: If baby flips onto their tummy while wearing a sleep sack, the sack can ride up covering their face/head which poses a suffocation hazard.

– Standing risk: If baby can stand, they may be able to climb out of the crib but get trapped if their legs are restricted in the sleep sack.

So most pediatricians recommend switching to a loose blanket once baby shows they can roll over or stand up, regardless of their age. Generally this happens between 6-12 months, but every baby reaches these milestones at their own pace.

When Baby Starts Climbing Out of the Crib

Once baby learns how to climb or scale the sides of their crib, it’s definitely time to lose the sleep sack. At this point, the sack could prevent them from getting their legs over the railing, leading to potential falls. Most babies figure out how to climb between 12-18 months.

So if your active, adventuresome baby is trying to escape the crib before age 2, move to a loose blanket even if they are not rolling over or standing yet. Safety should come before age guidelines.

Considering Baby’s Overall Development

While age ranges, mobility skills and climbing ability are good starting points, it’s also important to consider baby’s overall physical and cognitive development when deciding on transition time. Here are some developmental signs that signal readiness for a loose blanket:

– Fine motor skills to grasp and manipulate a blanket
– Understanding of object permanence – knows the blanket remains when out of sight
– Able to uncover themselves if blanket covers face
– Developmental maturity to sleep safely without swaddling or sack

Talk to your pediatrician if you are unsure if your baby is developmentally ready to use a loose blanket based on their individual growth and progression. Every child reaches these milestones differently.

Factors that May Delay Transition

While most babies are developmentally ready to transition around age 2, some factors may warrant continuing sleep sack use a bit longer:

– Premature birth: Babies born premature may reach physical milestones later, needing more time in a sack.

– Special needs: Children with special needs or developmental delays may need extra time to progress.

– Small stature: Particularly small or thin babies may rely on the warmth and security of the sack longer.

– Temperature regulation issues: Babies who have trouble maintaining their body heat may need the sack for added warmth.

If any of these apply to your child, discuss with your doctor before transitioning based on age alone. Adjust the timeline based on their specific needs and development.

Gradual Transition from Sleep Sack

It’s best not to go straight from the sleep sack to a loose blanket overnight. A gradual transition over a week or two helps baby adjust:

– Put baby to sleep in the sack, then remove later in the night for a period of time.

– Try nap times first without the sack before moving to nights.

– Use a wearable blanket or transitional swaddle before switching to a loose blanket.

– Move to a thin muslin blanket first before thicker, warmer blankets.

Go slow with the change to help baby get comfortable falling asleep without the familiarity of the sleep sack. Watch for any setbacks or sleeping issues.

Using Blankets Safely

Once you do move to loose blankets, follow these tips to maintain a safe sleep environment:

– Keep crib free of pillows, stuffed animals and other soft bedding.

– Use a thin, breathable blanket tucked in around mattress. Avoid loose blankets.

– Ensure baby’s head remains uncovered during sleep.

– Continue room temperature of 68-72°F for optimal sleep.

– Follow all other safe sleep guidelines like back sleeping without crib bumpers.

Check on your little one frequently as they adjust to the new blanket. Ensure face remains uncovered and they are sleeping soundly in the new bedding.

Signs Baby is Ready for a Loose Blanket

Look for these signs your baby is developmentally ready to safely transition out of the sleep sack:

– Rolls over and changes positions easily while sleeping

– Sits up on own and has head/neck control

– Crawls or pulls self up on furniture

– Developed object permanence skills

– Can grasp, manipulate and purposefully move a blanket

– Attempts to climb out of the crib

– Outgrowing current sleep sack size

– Shows maturity and independence in sleep habits

– No longer startles or flails arms when loosely swaddled

Use your parental intuition along with your pediatrician’s input to determine the right time to ditch the sack based on your baby’s unique abilities and needs.

Special Safety Considerations

Some babies may require extra safety precautions with bedding:


Babies born before 37 weeks may have underdeveloped lungs, muscle tone, sucking ability, and temperature regulation. Preemies should remain in a sleep sack longer until reaching full development.

Respiratory issues

Babies with breathing issues like asthma may need their head elevated for sleep. Avoid bedding near the face and medical advice.

Heart conditions

Babies with heart defects should sleep on their back to improve circulation. Loose bedding could impact breathing.


Babies with reflux should sleep at an incline. Use wedge sleepers instead of blankets, which could block airway if vomited.


Babies with seizures may need extra breathing precautions during sleep. Avoid bedding and keep sleep space clear.

Discuss any underlying medical conditions with your doctor for personalized sleep sack transition advice.

The Bottom Line

There is no definitive age when baby should move from a sleep sack to loose bedding. Consider their mobility, climbing skills, maturity, and overall development. Most babies make the transition sometime between 12-24 months. Work with your pediatrician on timing based on baby’s unique needs and abilities. Move gradually to a loose blanket and ensure safe sleep practices remain in place. The top priority is maintaining a secure sleep environment as your active baby becomes more independent!

Frequently Asked Questions

When should I stop swaddling and move to a sleep sack?

Most experts recommend transitioning from a swaddle to a sleep sack around 2-3 months or once baby shows signs of trying to roll over. The swaddle can interfere with development once baby is more mobile.

Are sleep sacks safe for naps too?

Yes, sleep sacks are considered safe for both nighttime sleep and naps. Follow the same transition timing for both.

What if baby resists the change from sleep sack to loose blanket?

Some babies are comforted by the enclosed, womb-like feel of the sleep sack. Make the transition gradual over a week or two. Use blankets that feel similar to the sack fabric. Provide extra soothing and comfort during the adjustment period.

Can I put a blanket over a baby in a sleep sack?

No, never put additional blankets on top of a sleep sack. The sack is designed to provide sufficient warmth on its own. Extra blankets could pose a risk of overheating or suffocation.

What about using wearable blanket alternatives?

Wearable blankets that zip or snap around baby can be a good transitional product after stopping use of the standard sleep sack. They allow more leg movement while still providing warmth and security.


The shift from sleep sack to loose bedding is an important transition as baby becomes more mobile and active at night. Take it slowly and base the timing on baby’s development, not their age. Work with your doctor to determine when your child has the skills to sleep safely without the enclosure of the sack. Maintain a secure sleep environment with guidelines like back sleeping and no pillows or stuffed animals. While it seems like a simple change, moving from a sleep sack to a loose blanket represents a big step towards more independent sleep for your baby!

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