The 4 month sleep regression often shows up between 3 and 5 months. A baby who had started giving longer stretches of sleep may suddenly wake more often, fight naps, or take only 30 to 45 minute naps.
This article explains what is changing, the usual signs, and what helps.
Key Takeaways
- Common signs include frequent night wakings, short naps, harder settling, and more fussiness around sleep time.
- Often lasts around 2 to 6 weeks.
- Most 4 month olds do best with roughly 1 hour 30 minutes to 2 hours 15 minutes of awake time between sleeps.
- A steady sleep environment, flexible wake windows and good daytime feeds help the most.
What Is the 4 Month Sleep Regression?
At 3 to 4 months, patterns of lighter and deeper sleep start to develop. At the end of a sleep cycle, babies are more likely to surface and wake fully. Linking those cycles is a new skill, so sleep often gets disrupted for a while.
Why It Happens
Many babies are becoming more aware of their surroundings, starting to roll, or getting more distracted during feeds. That can mean shorter daytime feeds, more unsettled naps and extra waking overnight.
Signs of the 4 Month Sleep Regression
Common signs include:
- Naps ending after one sleep cycle, around 30 to 45 minutes.
- Frequent night wakings, sometimes every 1 to 2 hours.
- Fussiness at the wind-down or at bedtime.
- Longer time to fall asleep.
- Earlier morning wakes.
- Increased night feeds.
4 Month Wake Windows
Most 4 month olds do well with roughly 1 hour 30 minutes to 2 hours 15 minutes of awake time between sleeps. Four naps a day is still common but some babies start transitioning towards three.
What Helps
- A dark room, comfortable temperature, and consistent white noise can help.
- Offer full daytime feeds when you can. Many babies get distractible at this age, which can push more feeding into the night.
- Use wake windows flexibly. If a nap was poor, the next window often needs to be shorter.
- Avoid making several big changes at once. Small, steady adjustments work better than a full routine overhaul.
When to Speak to Your GP or Health Visitor
Most 4 month sleep regressions are developmental rather than medical, but seek advice if:
- Your baby is refusing feeds or producing fewer wet nappies than usual.
- You have concerns about their breathing during sleep.
- They seem unwell, feverish, or showing ongoing distress.
- You are struggling with your own wellbeing.
- They are not gaining weight as expected.
Frequently Asked Questions
Can I sleep train during the 4 month regression?
Most parents find it easier to begin structured changes once the 4 month sleep regression settles. Keeping the sleep environment and wind-down consistent are usually more effective in the short term.
Will my baby go back to sleeping through the night?
Longer stretches usually return as your baby adjusts to the new sleep pattern.
Is the 4 month regression always at 4 months?
It can appear anywhere from around 3 to 5 months. The label is a rough guide rather than a fixed schedule.
Related Reading
- 4 month old wake windows
- Wake windows explained
- Tips to help your baby sleep
- Why white noise and red light help baby sleep
This article is general information and not medical advice. If you have concerns about your child's health, breathing, feeding, or sleep, please speak to your health visitor, GP, or paediatrician.
