Sleep regression in babies and toddlers: When and why it happens

Just when you're starting to get real sleep again, it happens – your baby reverts to waking frequently at night, has a hard time going to sleep, wants to feed again throughout the night, or wakes up at odd hours and can't get back to sleep. This is called sleep regression, and many young children experience it.

What is sleep regression?

Generally speaking, sleep regression describes temporary periods when babies or young children don't sleep as well as they have in the past. It's not a scientific or medical term, but you may hear it from parents, sleep consultants, and pediatricians.

Sleep pattern changes are normal as kids grow and develop – and they're often temporary. That said, many people suspect that sleep regression can be brought on by a change in your child's routine (like a vacation or sickness) or an approaching developmental milestone (like learning to crawl, stand, or walk, or starting to potty train).

Sleep regression often passes on its own, but it sure does make sleeping rough in the meantime. There are plenty of ways you can help your baby get back on track, including sleep training.

For in-depth information on sleep training, including night-by-night plans, check out BabyCenter's Baby Sleep 101 courseOpens a new window.

Sleep regression ages

Not all children go through sleep regression – some babies start sleeping easily at night and never look back. However, parents commonly report problems with their child's sleep patterns at 4 months, 6 months, 8 months, 12 months, and 18 months.

Sleep regression can happen any time during the baby and toddler years, except during the newborn period. That's because newborn sleep patterns are naturally erratic. During the first 3 months of life, it's normal for your baby to sleep for only a couple hours at a time and wake frequently during the night to eat.

Between 3 and 5 months old, babies usually start to sleep more during the night and have longer stretches of sleep – about 5 to 6 hours at a time – but will still wake often. Many babies learn to sleep through the night when they're anywhere from 4 to 9 months old, but this varies depending on your child.

Why does baby sleep regression happen?

Your baby's sleep habits can change – and appear to take a step backward – for many reasons. Possible explanations for sleep regression include:

• Sleep shifts: Between 3 and 6 months old, most babies adjust their sleep patterns to be awake more during the day and asleep for longer periods at night. Their sleep cycles start to become more like an adult's in how they alternate between light sleep and deep sleep. But as your baby shifts between sleep stages, they may wake and not be able to get themself back to sleep. (Adults and older children also wake during the night for this reason, but usually fall back asleep immediately.)
• Milestones: Parents often report sleep regression around when their baby is learning a new skill, such as rolling over, crawling, or standing. Some experts say this may happen because babies are so preoccupied with learning the skill they want to practice it all the time, even at night. Also, if your baby has learned to stand, they may try to do this in their crib when they wake and then cry because they haven't figured out how to get back down yet.
• Environment changes: Small changes in your baby's surroundings can affect how well they sleep. Shifts in the weather could affect the temperature in your baby's room, making them too warm or too cold at night. Or maybe there's another outside disturbance, like a neighbor's outdoor light shining into their room or a dog barking.
• Separation anxiety: Between 6 and 12 months old, your baby begins to understand they're separate from you and may become anxious when you or your partner leaves the room. This separation anxiety typically peaks around 10 to 18 months old and fades by age 2. Your baby may cry out for you in the middle of the night, try to climb out of their crib, or want to sleep in your bed. Separation anxiety, though trying, is a normal part of your child's emotional development.
• Changes in routine: Maybe you went on vacation and your baby stayed up later than normal. Or your child has been sick and become used to you checking on them at night and rocking or soothing them to sleep. Any changes to your child's regular routine – or a time change – can temporarily throw off their sleeping patterns.

How long does sleep regression last?

If your baby does experience a sleep regression, you can expect it to last anywhere from two to six weeks.

Fluctuations in sleep patterns are completely normal during the first few years of life. Some children wake more easily than others or have a harder time establishing a regular sleep-wake cycle. And sleep regressions don't last forever – your baby will start sleeping normally again eventually.

But sleep difficulties sometimes happen because of an underlying health issue. If your child was regularly sleeping through the night and now regularly wakes several times a night for multiple days, let your child's doctor know. They can make sure there's nothing wrong – like an emerging ear infection – and offer you guidance on good sleep habits.

Health problems to look out for include:

• Illness: A fever or pain from an ear infection, upset stomach, or teething can keep your baby up at night.
• Sleep apnea: If your baby struggles to breathe while they're sleeping, it could be a sign of sleep apnea. It's normal for babies under 6 months to have irregular breathing and to pause for 5 to 10 seconds between breaths. But if your baby is breathing or snoring loudly, stops breathing for 20 seconds or longer, or wakes up gagging and choking, talk to their doctor. 
• Gastroesophageal reflux: If your child is frequently vomiting or spitting up large amounts of milk, they may have gastroesophageal reflux disease. This happens when the valve connecting the esophagus to the stomach isn't working properly and pushes your baby's acidic stomach contents back up into their mouth. Symptoms get worse when your baby is lying down, so it may disrupt their sleep. Talk to your baby's doctor if you think this might be the issue.

How to deal with sleep regression

If your child is at least 4 months old and having trouble getting to sleep or staying asleep, you may want to consider sleep training. You can choose between cry it out, no tears, and fading methods.

Here are some other ways to get your child's sleep back on track:

• Have a bedtime routine. If you haven't yet, start a predictable and soothing bedtime routine with your baby. This could be a bath, putting pajamas on, and reading a picture book or singing a song before kissing good night. Making an emotional connection with your child at bedtime helps them feel secure and ready for sleep.
• Put your baby in the crib when they're awake. Try not to let your baby fall asleep while they're eating, being rocked, or in your bed. Instead, put them in the crib when they're drowsy but not yet asleep so they fall asleep by themself. The goal is for them to learn to soothe themself to sleep, so you won't need to help them every time they wake up.
• Don't rush in. If you rush to check on your older baby immediately every time they cry and feed them, rock them back to sleep, or bring them into bed with you, they'll probably rely on this to go back to sleep. By 4 months, it's okay to let your baby cry for a short period to see if they'll settle back down on their own. If you need to go to them, pat them soothingly on the back instead of picking them up. Leave the room when they're calm but still awake.
• Make nighttime boring. Teach your baby that nighttime isn't exciting. If you have to change or feed your baby at night, do it quickly. Keep the activities quiet and matter-of-fact. If possible, keep the lights turned low. And give your baby lots of attention during the day so they learn that daytime is playtime.
• Stay consistent. Try to stick to your bedtime routine and sleep guidelines, even during difficult periods. Make sure your partner and any babysitters or caregivers know the routine and guidelines as well. If your child gets off track because of illness or another interruption, get back to the routine as soon as possible.
• Wean off nighttime feedings. Between 4 and 6 months old, most babies get enough calories during the day and can go through the night without eating. If you think you and your child are ready, start to gradually wean them off nighttime feedings.
• Make sure your child is comfortable. Check that the temperature isn't too hot or cold in your baby's room. If it's chilly, put them in a cozy and safe sleep sack. Be aware of outside noises or lights that may be keeping your baby up. Try using a white noise machine or fan to drown out other noises and use blackout curtains to keep light out. If your older baby or child is uneasy about the dark, it's fine to use a nightlight or let light from the hallway spill into their room.
• Help your child with ups and downs. If your child recently learned to stand up, they may have trouble getting back down. They may also cry for help at night after standing up in their crib. During the day, help them practice getting down by supporting them as you press firmly against the back of their knees until they buckle.
• Offer them a lovey. Many older babies and toddlers like to cuddle with a blanket or soft toy when they go to bed. But don't put loveys in the crib until your child is at least 1 year old, because they can be a suffocation hazard. (Learn more about safe sleep for babies.)
• Stay calm. Try to be understanding, even when your child's sleep behavior is frustrating and tiring. If you get angry or upset, you could make the sleep problems worse. Staying relaxed will help calm your child as well.

How to cope with sleep regression as a parent

It can be stressful and exhausting when your child wakes frequently during the night or doesn't go to sleep easily. It's especially hard when you've gotten used to easier nights and are suddenly back in the land of the sleep-deprived.

These tips can help:

• Nap when you can. If you're home during the day, try to nap when your baby naps so you get more sleep. If you're at work, you may be able to take a power nap during lunch in your car or an unused office.
• Manage sleep deprivation. If naps aren't possible, look into ways to cope with your lack of sleep during the day. There's no substitute for good rest, of course, but you can make your fatigue a little more manageable by eating a balanced, healthy diet and staying hydrated; coping with stress through yoga, meditation, and exercise; and avoiding substances like alcohol and tobacco.
• Keep things in perspective. This too shall pass – your child's sleep regression is temporary. Most children return to good sleep patterns within a few days, weeks, or, at the most, months.
• Ask for help. If possible, share nighttime (and daytime) baby duty with your partner or another loved one so you can both get at least some sleep. Talk to other parents in the BabyCenter Community about your child's sleep challenges and make a plan of action. Ask your child's doctor for advice on how to improve your child's sleep. If this doesn't work, consider hiring a sleep consultant to help you find solutions.