Any baby or toddler can have a restless night. Sleep regression, however, is a prolonged period of sleep disruption that lasts 2-6 weeks before stabilizing again. Even “good sleepers” may suddenly struggle—fighting naps, fussing at bedtime, and waking up more often during the night.

The good news: Sleep regression is temporary. As exhausting as it is, it’s often a sign of healthy child development. Something to think of as a progression, really. Here’s what to know about changing sleep patterns and how to help little ones through them.

When do babies and toddlers experience sleep regression?

Newborn sleep patterns are naturally erratic, which can be tough for new parents. But baby's sleep usually stabilizes:

• Around 3-5 months, many babies begin sleeping 5-6 hours at a time.
• By 4-9 months, many babies sleep through the night.

Toddlers need fewer naps as they get older:

• Around 18-24 months, most transition to just one daily nap.
• By 2.5-3 years, many toddlers are ready to skip naps entirely.

But every child is different. Some parents don’t notice sleep changes, while others experience significant disruptions when their child’s sleep shifts in months 4, 6, 8, 12, and 18.

You might also like: Grow with the Flow Month 4: Sleep Disruptions

What causes sleep regression?

Sleep habits can change for several reasons, some within a parent’s control and many beyond it. The important thing to remember is that sleep regression is a normal and temporary part of child development.

Brain sleep cycle changes

Around 3-6 months, the sleep patterns of most babies begin to look like ours. They’re awake more during the day and sleep for longer periods at night, with periods of light and deep sleep.

It’s normal to wake in the transition between sleep stages, but older children and adults usually fall back asleep immediately. Babies don’t have this skill at first. They wake and cry, because they’re unable to get back to sleep on their own.

Developmental milestones

Sleep regression often coincides with learning new skills, like:

• Rolling over (4-6 months)
• Crawling and standing (6-10 months)
• Walking and language development (12 months)
• Increased independence and boundary testing (18 months)

As little one masters these milestones, their brain is more active and eager to try skills again and again. It’s hard to turn that off to rest.

Separation anxiety

Around 6-9 months, baby develops object permanence, the understanding that people and things continue to exist, even if baby can’t see them. This triggers separation anxiety, but also supports more secure attachment, once baby understands that caregivers who leave will eventually return.

You’re baby’s safe space and most trusted and beloved person. Baby knows they’re separate from you when they go to sleep, so they may fight naps and bedtime. When they wake, they immediately want comfort from you.

You might also like: Grow with the Flow Month 9: Object Permanence

Changes in routine

Little ones thrive in routine. Even seemingly small changes can disrupt their day-to-day functioning.Traveling to a different time zone can disrupt not just sleep, but the entire day’s schedule. Even the one-hour shift during Daylight Saving Time affects sleep and wake patterns.

Changing naptime and bedtime routines—for example, starting daycare and having another caregiver manage naptime or switching up the order of dinner, bath, and bedtime—can throw babies and toddlers off.

You might also like: Why Routine Is Baby’s Foundation For Brain-Building & Connection

Changes in environment

Our surroundings also impact sleep. You may have experienced this already, if you’ve transitioned from co-sleeping to putting little one in their own bed or room. Moving from a crib to a big kid bed is another exciting, but sometimes anxious, adjustment.

Changes outside often have implications inside. Shifts in weather can affect room temperature and ambient noise. Neighborhoods can transform from sedate in winter to bustling in summer.

Physical issues

Teething, illness, allergies, asthma, and acid reflux can also disrupt sleep in babies and toddlers. Watch out for fever, vomiting, and breathing difficulties, and consult your pediatrician about treatment.

You might also like: How To Navigate Cold & Flu Season With Little Kids

How can parents help babies and toddlers during sleep regression?

Watch for sleepy cues

Little ones quickly go from overtired to wired, due to high levels of cortisol and adrenaline. Get babies and toddlers down for some rest when you notice yawning, fussiness, and eye rubbing during the day. It can help them sleep better at night.

Stick to a consistent bedtime routine

Bedtime isn’t only about the time, but also the process of unwinding at the end of the day. It often involves a last feeding, bath, bedtime story, lullabies, and cuddles. Even as sleep shifts, put little one down for the night with the same familiar series of activities.

Practice sleep hygiene at night

Create a soothing sleep-friendly environment at home by dimming lights in preparation for bedtime. Use blackout curtains or close blinds to keep bedrooms dark. Limit screen time or overstimulating activities before bed. Try your best to make the last hours before bed a time for quiet connection and winding down.

Is sleep hygiene always possible with babies, toddlers, and busy parents? Of course not! But it’s something to aim for—and something that can benefit the entire family.

Be patient

Sleep regression is tough on everyone at home. Do what you can to carve out time for your own rest. This may mean delegating household and parenting duties differently with your partner, calling in reinforcements, or shifting priorities a bit.

Be patient with yourself and the cute little person keeping you up at night. Sleep patterns will stabilize soon. Sleep regression is often developmental progression. Take one day (and night) at a time…

References

Valla, L., Wentzel-Larsen, T., & Slinning, K. (2022). Sleep problems reduced from 6 to 24 months of age with no evidence of links between disturbed sleep and later developmental problems. Acta Paediatri. Retrieved March 17, 2026.

Scher, A. & Cohen, D. (2015). Sleep as a mirror of developmental transitions in infancy: the case of crawling. Monogr Soc Res Child Dev. Retrieved March 17, 2026.

Bemanalizadeh, M., Parsapoor, M., Emami, L., Imani, V., Parsapour, Z., & Kelisahdi, R. (2024). The association between sleep consolidation and growth and development in early childhood: A systematic review. Health Promot Perspect. Retrieved March 17, 2026.