You finally got a stretch of sleep. Your baby was starting to settle. And just when you dared to breathe easy, the night wakings returned. Naps shortened. Fussiness increased. And you’re left wondering what went wrong.
The answer may be more common than you think: a sleep regression.
Sleep regressions are a hallmark of infancy. They’re frustrating, confusing, and often poorly timed but they’re also a normal part of your baby’s development. Understanding what’s happening, why it’s happening, and how to respond can make all the difference.
Sleep Regression
A sleep regression is a period usually lasting anywhere from a few days to a few weeks when a baby who was sleeping relatively well suddenly starts waking more often, struggling to settle, or skipping naps altogether.
Unlike occasional bad nights caused by illness, teething, or travel, regressions tend to follow a more developmental pattern. They’re often linked to:
- Brain development and cognitive leaps
- New motor skills (like rolling, crawling, standing)
- Emotional growth (such as separation anxiety)
- Shifts in sleep architecture as babies mature
These changes temporarily disrupt a baby’s sleep not because something is wrong, but because so much is going right.
“Sleep regressions are often misunderstood as setbacks. In truth, they reflect important developmental progress.”
— Dr. Craig Canapari, Director of Yale Pediatric Sleep Center (source)
When Do Sleep Regressions Happen?
While every baby is different, there are a few common ages when regressions tend to strike:
- 4 months: A major neurological shift causes lighter sleep cycles and frequent waking
- 8–10 months: Crawling, pulling up, and increased awareness disrupt rest
- 12 months: Walking and new words can make sleep a lower priority
- 18 months: Separation anxiety peaks, independence surges
- 24 months: Language explosions and imagination affect sleep again
These aren’t guaranteed, but they’re so predictable that many experts refer to them as “milestone regressions.”
Why Does It Happen So Suddenly?
Sleep regressions often feel like they come out of nowhere. One week, your baby sleeps six-hour stretches. The next, they’re waking every 90 minutes and only napping in your arms.
The reason? Brain growth is not gradual — it’s leapy.
According to the American Academy of Pediatrics, infants undergo rapid cognitive and neurological development in their first two years. During these “growth spurts,” babies may process the world differently, become more aware of their surroundings, or experience heightened anxiety about separation all of which can affect sleep (AAP).
In short: your baby is changing, and their sleep reflects it.
What Can You Do to Help?
The good news: sleep regressions are temporary. But there are steps you can take to ease the disruption for both your baby and yourself.
1. Reassess Your Baby’s Wake Windows
One of the most overlooked causes of disrupted sleep is overtiredness. As babies grow, their ideal wake windows shift. A baby who once needed a nap every 90 minutes might now stay awake for 2–3 hours.
Check updated sleep needs by age, such as the ones recommended by the American Academy of Sleep Medicine (AASM Guidelines), and observe your baby’s cues.
2. Stay Consistent with Bedtime Routines
Even when naps are unpredictable or night sleep is fragmented, try to keep your bedtime routine consistent – dim lights, quiet sounds, a warm bath, or gentle books. Ritual creates security and predictability.
Research shows that consistent bedtime routines help babies fall asleep faster and wake less during the night (Mindell et al., 2009).
3. Offer Extra Comfort
Sleep regressions can heighten separation anxiety. Your baby might cry more when put down or wake looking for you. During these times, your presence is a comfort, not a crutch. Hold them a little longer, co-sleep if it’s safe for your family, or offer calming touch.
4. Protect Your Own Rest
Yes, your baby is struggling but you matter too. Tag in a partner, nap when you can, or let chores slide. This is a temporary phase, but exhaustion can affect your mental health and your ability to respond gently.
If sleep deprivation is affecting your ability to function, speak with your doctor or pediatrician. You’re not alone.
When to Worry (and When Not To)
Sleep regressions are normal, but it’s wise to keep an eye out for other issues. If your baby also has:
- A high fever
- Difficulty breathing
- Unusual irritability or lethargy
- Refuses to feed
…these may point to something beyond a regression. Always consult your pediatrician if something feels off.
Want to Know What to Expect Next?
Every sleep regression is different and how you respond can shape your baby’s comfort and confidence moving forward.
That’s why this expert-backed guide on baby sleep regressions and how long they last is a must-read for parents navigating this stage. It walks you through each major regression by age, why it happens, and how to support your baby through it without pressure, guilt, or unrealistic expectations.
Final Thought: This Too Shall Pass
Sleep regressions are tough, but they don’t last forever. With understanding, patience, and a little support, you and your baby will move through this phase and emerge stronger, more connected, and ready for the next adventure.
Remember: if your baby’s sleep just got worse… it’s not your fault. It’s a sign they’re growing.
