The 4-Month Sleep Regression
Medically reviewed by Safi Ullah Khan
Medically reviewed by Safi Ullah Khan · Written by Muneeb Rana · Last updated 21 October 2026
Quick answer: The 4-month sleep regression is a common period, usually between 3 and 5 months, when a baby who slept fairly well starts waking more often and napping shorter. It reflects a lasting change in sleep cycles, not a problem. It usually settles within 2-6 weeks. Keep routines consistent and follow safe sleep rules throughout.
TL;DR
- Common between 3 and 5 months.
- More night wakings, short naps, fussiness.
- Usually eases in 2-6 weeks with a steady routine.
The 4-month sleep regression isn't a medical term, but almost every parent recognises it. Here's what's going on and what helps.
Why it happens
Around 3-4 months, babies' sleep matures into cycles more like adults', with lighter phases between them. They surface more often and may need help to fall back asleep. Rolling, more awareness and growth all add to it.
Signs
- More night wakings than a few weeks ago
- Short naps of 30-45 minutes
- Fussiness and fighting sleep
- Wanting to feed more at night
What helps
| Try | Why |
|---|---|
| Consistent bedtime routine | Predictability cues sleep |
| Age-appropriate wake windows (1.5-2.5 h) | Avoids overtiredness; see the wake window calculator |
| Dark room, white noise | Fewer disturbances between cycles |
| Some drowsy-but-awake practice | Helps babies link cycles |
| Stop swaddling if rolling | AAP safe sleep advice |
How long does it last?
Most families see things settle within 2-6 weeks. The changed sleep cycles are permanent, but babies learn to link them. Check the timing of other common regressions with the sleep regression calculator.
When it's not just a regression
If wakings come with fever, ear pulling, vomiting, rash or fewer wet diapers, your baby may be unwell; call your pediatrician.
Using a sleep log
A week of sleep data in Tot shows whether things are improving, and helps you spot naps that are too late or wake windows that are too long.
Related: 4-month-old sleep schedule · 3-month-old sleep schedule · baby sleep tracker · how to track baby sleep
Download Tot free on the App Store or Google Play. Free with ads; optional Premium.
Sources
- AAP HealthyChildren.org: Getting Your Baby to Sleep: www.healthychildren.org (accessed 21 October 2026)
- AAP HealthyChildren.org: Healthy Sleep Habits, How Many Hours Does Your Child Need?: www.healthychildren.org (accessed 21 October 2026)
- AAP HealthyChildren.org: How to Keep Your Sleeping Baby Safe (AAP policy explained): www.healthychildren.org (accessed 21 October 2026)
- NHS: Helping your baby to sleep: www.nhs.uk (accessed 21 October 2026)
Medical disclaimer:
Tot and this website give general information only. Feeding, sleep and growth ranges vary; always follow your pediatrician's advice. If your baby is unwell, contact your doctor or emergency services.
FAQ
Does every baby have a 4-month sleep regression?
No, but many do. Some have it earlier or later.
Should I feed more at night?
Offer a feed if your baby seems hungry. Not every waking is hunger.
Is it a growth spurt?
It can overlap with one, which may increase hunger for a few days.
Should I start sleep training now?
That's a family decision; discuss with your pediatrician. Many wait until after 4-6 months.
How do I know it's ending?
Longer stretches return and naps lengthen. A sleep log makes this easy to see.
Related guides
Track this in Tot
Tot is a free baby tracker app for iPhone and Android that logs breastfeeding, bottle feeds, sleep, diapers, growth, vaccines and medicine, and lets parents share the log with a partner or caretaker.
