The 4-month sleep regression is when a baby’s sleep patterns change. It is the first of many new sleep patterns babies experience as they mature. Not all babies experience it.

Sleep coaches, parents, caregivers, and parenting apps suggest that babies may experience many sleep regressions, usually beginning at 4 months.

There is little scientific research into the 4-month sleep regression, and no formal studies have tested this theory. That does not make the sleep regression any less real, but it does mean that researchers do not know how many babies experience it, how long it typically lasts, or which symptoms are most common.

a baby lying awake as it's undergoing the 4 month sleep regressionShare on Pinterest
A consistent bedtime routine may help manage sleep regressions.

Some potential symptoms may include:

  • Deterioration in sleep pattern: The baby might regress to an earlier sleep pattern. Or a baby who was beginning to establish a sleep schedule might wake more frequently or have more trouble falling asleep.
  • More difficulty falling asleep: A baby may have more trouble falling asleep, and may even appear to be resisting sleep. Some babies may stay up so long that they appear overtired, and seem to have more difficulty falling asleep.
  • Shifting nap routines: Some babies may nap less frequently or drop one of their daytime naps.
  • More frequent nighttime wakings: A baby may begin waking more frequently at night, and it may be difficult to get them back to sleep.
  • Disturbed sleep: Babies may be more active when sleeping, rolling over, or thrashing during sleep.

There is no right way to manage sleep regressions. Some caregivers, for example, feel strongly about nursing a baby to sleep. Others believe that doing so can make it more difficult for a baby to sleep.

Numerous strategies may help. Parents should choose those that are consistent with their values and lifestyle:

  • Avoid television: A 2010 study found that babies who watched TV early in life may be more likely to have sleep difficulties.
  • Do not introduce solids too early: It is a myth that cereal in a bottle will help a baby to sleep through the night. Instead, this increases choking risk. A 2010 study correlated early introduction of solids with more sleeping difficulties.
  • Create a consistent bedtime routine: This helps the baby prepare for bed and can ease bedtime stress. An article in the Journal of Family Psychology found that mothers who were emotionally available to their babies at bedtime found that they slept better.
  • Put the baby to sleep in a cool, dark, quiet room.
  • If the baby is not yet rolling over, use a swaddle: A swaddle might help a baby to them sleep. It is important to swaddle a baby correctly.
  • Consider using a pacifier at bedtime. Sucking the pacifier may comfort the baby when they are not feeding.
  • Invest in a white noise machine: The soothing sounds may block out ambient noise, and help babies fall and remain asleep.

Some sleep counselors say that the 4-month sleep regression is different from later sleep regressions. While those sleep regressions typically last a few weeks, the 4-month regression may mark a permanent change in the baby’s sleep pattern.

Babies may begin sleeping less deeply at 4 months, making it harder for them to fall asleep and stay asleep. Around 4 months, a baby switches from a newborn sleep schedule to that of an older baby.

They may need slightly less sleep — 12 to 15 hours per day, compared to 14 to 17 hours per day during the first few months of life.

Moreover, many babies face other changes around this age, too. Some babies start rolling over, which means they can no longer sleep in a swaddle. This can make staying asleep more difficult, particularly if a baby wakes while rolling over in their sleep.

They may outgrow a bedside bassinet, which could mean a transition to a crib–and possibly a transition out of the caregivers’ room.

Also, may babies no longer need an overnight feed, which could result in several hours of broken sleep for the baby and the caregivers.

It can take time to adapt to these significant changes. Caregivers may need to change their bedtime routines and steadily adjust to a shift in the baby’s sleeping schedule and habits.

Baby sleep problems can leave caregivers exhausted, especially when babies frequently wake during the night. Over time, this can increase the risk of depression and make it difficult to feel attentive and engaged during the day.

These tips may help:

  • If there are multiple caregivers, take turns getting up with the baby.
  • If the baby is nursing and there are two caregivers, the other can get up with the baby in the morning so that the one who was up nursing at night gets to sleep in.
  • Ask for help from loved ones to manage daytime tasks so that fatigue has less of an effect on daily life.
  • Consider hiring a childcare provider to help get a nap or two during the day.
  • Practice anxiety and depression management techniques, such as meditation and deep breathing. If a caregiver feels frustrated or angry, take a break and ask another caregiver to intervene.
  • Talk to a therapist about symptoms of depression or anxiety.
  • Get help from a doctor or sleep expert.

The 4-month sleep regression is not a medical problem, but a pediatrician may be able to help or refer caregivers to a sleep expert.

Talk to a doctor if:

  • a caregiver experiences depression, anxiety, or very poor mental health
  • the baby sleeps so little that caregivers feel unable to function during the day
  • the baby consistently gets less than 10 hours or more than 18 hours of sleep in a 24 hours
  • sleep regression does not improve after several weeks of trying management strategies

The 4-month sleep regression can test even the most patient caregivers, especially when a baby only recently began sleeping on a semi-regular schedule.

All babies eventually sleep at night, so while this transition may be difficult, it is not permanent.