The 18-month sleep regression usually happens in the middle of a child’s second year. Several factors may cause it, but it is not a permanent issue.
While little formal research has explored sleep regressions at any age, most anecdotal evidence suggests that a sudden change in babies’ and toddlers’ sleeping style is common.
No peer-reviewed research has tested the notion of an 18-month sleep regression, and there is no scientific evidence that this is a standard developmental milestone.
However, many sleep specialists emphasize that toddlers commonly experience a change in sleeping habits at around 18 months of age. Changes in an infant’s brain development, daily habits, and skills, along with shifts in their circadian rhythms, might cause their sleep to change.
During the 18-month sleep regression, even toddlers who once slept well may sleep less or have more trouble falling asleep.
Several factors may contribute to the 18-month sleep regression, including:
- Separation anxiety: Separation anxiety tends to peak around this age, making it more difficult for a child to fall asleep without a parent or caregiver.
- Changes in the baby’s circadian rhythm: Some sleep specialists believe that a baby’s natural sleep cycle changes in toddlerhood, so the infant may go to bed later and possibly wake later. Some toddlers’ nap schedules change, too.
- Emerging independence: Thanks to new skills, such as walking and talking, and an increased understanding of the surrounding world, many toddlers do not want to sleep. They may deliberately fight sleep by thrashing around or delaying bedtime.
- Physiological health issues: Occasionally, what appears to be sleep regression is something else, such as sleep apnea or acid reflux. If the toddler is in pain, or the sleep regression lasts more than a few weeks, parents or caregivers should take the infant to see a doctor.
Some signs and symptoms of the 18-month sleep regression include:
- taking longer to fall asleep
- waking more frequently at night
- crying at night
- getting out of bed or being more active at night
- regressing in other areas of sleep — for example, relying on sleep aids that they once did not need, such as nursing to sleep or snuggling with a parent or caregiver
The 18-month sleep regression does not always occur at exactly 18 months. It may happen at any time during a child’s second year.
As no research has verified the existence of the 18-month sleep regression, there is no proven method for managing it. However, some standard sleep management strategies may help, including:
Making bedtime relaxing, warm, and affectionate
Resist the temptation to threaten or punish a child who does not want to go to sleep. Instead, offer love, affection, and calm reassurance.
A 2010 study found that infants aged 1–24 months whose mothers were emotionally available at bedtime slept longer and better.
Putting to bed drowsy
A technique called graduated fading involves putting a child to bed when they are drowsy but not asleep to help them learn to fall asleep on their own. A small 2016 study of infants aged 6–16 months found that this approach may improve sleep.
Many parents and caregivers use this technique in the baby’s first year of life. Those who found it effective may wish to try it again at the 18-month stage.
To use this technique, parents or caregivers must learn to recognize a child’s tiredness cues. Once the child is drowsy, it is important to put them to bed without delay. Continuing to play or read stories past this point may make a toddler overtired and, therefore, less likely to sleep.
Some people try leaving their toddlers to cry alone for brief periods, hoping that the toddler will learn to “self-soothe.” This method remains controversial because some people worry about the well-being of the child.
Experts recommend different approaches, ranging from leaving a child to cry for as long as it takes them to fall asleep to leaving them to cry but soothing them at regular intervals.
A small 2016 study compared babies whose parents let them cry for short periods with a control group. There were no differences in long-term behavior and no significant differences in attachment. This finding suggests that controlled crying may be safe for parents and caregivers to try.
It is worth noting, though, that this practice is easier to introduce when a baby is younger than 1 year. Parents and caregivers who used the technique then may find it beneficial to reintroduce it.
People should establish a predictable, soothing bedtime routine. A routine works well because parents and caregivers can use it with any other sleep intervention.
Some options for a routine include:
- reading stories
- reflecting on the day
- singing songs
- gentle massage
- a warm bath
It is advisable to follow the same routine in the same order every day and to avoid habits that make kids anxious or increase their energy.
A 2017 study of babies and toddlers found that a bedtime routine could improve sleep in just a few days.
Other lifestyle changes
Making certain changes to a child’s daily routine may help them sleep better. These can include:
- avoiding any caffeinated foods and drinks
- dropping one of the toddler’s two naps and shifting the time of the remaining one
- giving the toddler time outside to help regulate their circadian rhythms by exposing them to natural light
- keeping things calm and relatively quiet in the hour or two leading up to bedtime
- keeping the child physically active during the day
The 18-month sleep regression may cause stress and lack of sleep for parents and caregivers. It is important for them to look after their physical and emotional well-being as well.
Some strategies that can help parents and caregivers cope with 18-month sleep regression include:
- Practicing calming sleep rituals: Yelling, anxiety, and anger can make sleep problems worse while making the bedtime ritual more stressful. People should experiment with strategies that help them feel calm at their toddler’s bedtime.
- Sharing the work: When there are multiple caregivers, they should work together to reduce one another’s stress. Try taking turns getting up with the child or alternating nights so that each caregiver has the chance to get a full night’s sleep.
- Getting expert help: Pediatricians and sleep consultants can offer personalized recommendations that may help children sleep better and longer, which may benefit parents and caregivers too.
Perhaps most importantly, people should remember that sleep regressions are temporary and that there is no one perfect way to deal with them.
Parents and caregivers must find a strategy that works for them. There is no evidence that any single strategy works best or that any approach is harmful or beneficial to a child’s emotional or intellectual development.
There are no scientific data on the 18-month sleep regression and no specific timeline for how long it lasts. Many parents and caregivers find that things improve within days to weeks.
For some, the 18-month sleep regression marks a permanent change in the child’s sleep habits. The toddler might drop a nap, stay up later, or sleep later in the morning. Even when there are permanent changes, however, sleep tends to improve with time.
The 18-month sleep regression is not a sign that something is wrong with the caregiver or child. Instead, it is one of the many ups and downs to expect when trying to help children sleep.
If the regression lasts for longer than a few weeks, or if a toddler seems to be ill or have trouble functioning due to exhaustion, talk to a pediatrician.