The 4-Month Sleep Regression: What It Is and How to Get Through It
Your baby was sleeping well, and then suddenly they're waking every hour, fighting naps and only settling in your arms. If they're somewhere around 3–5 months old, you've probably met the 4-month sleep regression.
What's actually happening
Despite the name, this isn't really a step backwards. It's a permanent change in how your baby sleeps. Around this age, their sleep starts to look more like ours, cycling between lighter and deeper stages.
That means more brief wake-ups between sleep cycles. A baby who used to sleep straight through those transitions now notices them, and often needs help getting back to sleep.
Common signs
More night wakes, sometimes every 1–2 hours
Short naps of 30–45 minutes
Harder to settle at bedtime
Extra fussiness during the day
New skills like rolling, which they may want to practise at 2am
How to get through it
Keep your bedtime routine consistent. Predictability is reassuring when everything else feels chaotic.
Check wake windows. Babies this age often need a little more awake time than a month ago. Our free wake window calculator can help.
Make the room sleep-friendly. A dark room and white noise help your baby link sleep cycles more easily.
Practise drowsy but awake. Start with bedtime only. Putting baby down calm and sleepy helps them learn to fall asleep in their own space.
Be kind to yourself. Accept help, take turns with nights if you can, and remember this phase does pass.
A safety note
If your baby is showing signs of rolling, it's time to stop swaddling. Always place your baby on their back to sleep, on a firm, flat mattress with nothing else in the cot or crib. If your baby seems unwell, isn't feeding well or you're worried, speak to your health visitor, GP or pediatrician.
Need support?
The 4-month regression is one of the most common reasons parents reach out to me. The Full Support package gives you a personalised plan, two weeks of email support and a check-in call, so you're not navigating it alone.
