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The 4-Month Sleep Regression: What Is Happening and What Helps

Around 3 to 4 months many babies suddenly wake more at night. This guide explains the sleep changes behind it and gentle ways to cope.

Before you use this guide: This is general educational information, not an individual medical assessment. We do not identify a clinician reviewer on this page, so please confirm personal health decisions with your doctor, midwife or paediatrician.

Somewhere between about three and five months, many babies who were sleeping well start waking more often at night, fighting naps or needing more help to settle. This is commonly called the 4-month sleep regression. The name is popular but not a medical diagnosis, and it is not really a step backwards. It is a lasting change in how your baby sleeps.

What is happening

Newborns fall straight into deep sleep and sleep in short stretches around the clock. At around three to four months, your baby's body clock begins to mature and their sleep starts to follow cycles of lighter and deeper sleep, like an adult's, but shorter. Between cycles they briefly wake, and a baby who has always been helped to fall asleep may need your help again to get back to sleep. At the same time they are learning new skills, such as rolling, noticing the world and laughing, and may be going through a growth spurt.

Signs you may notice

• More night wakings, sometimes every hour or two
• Short naps of 30 to 45 minutes
• Being fussier and harder to settle
• Wanting more feeds, or being easily distracted at feeds

For most babies this lasts around two to six weeks. Some babies hardly notice it.

What can help

• A simple, calm bedtime routine, such as a bath, feed, song and cuddle, in the same order each night. It is a good time to start one.
• Watching wake windows (see our guide) so your baby is not overtired at bedtime.
• Sometimes putting your baby down drowsy but awake, so they practise falling asleep. There is no need to do this every time.
• A dark, quiet, cool room, at about 16 to 20 °C (61 to 68 °F).
• Plenty of daylight, activity and full feeds during the day.
• Offering feeds when your baby wakes hungry. Hunger is real at this age.
• Keeping night wakings calm and dull, with low light and little talk.
• Taking turns with a partner or helper so you can each get a longer stretch of sleep.

Keep sleep safe

• Put your baby to sleep on their back, on a firm, flat surface, in their own cot or bassinet in your room for at least the first six months.
• Never fall asleep with your baby on a sofa or armchair.
• Stop swaddling once your baby tries to roll over.
• Do not use sleep products that are not designed for overnight use, and avoid weighted sleep sacks.

What about sleep training?

Formal sleep training methods are generally not suggested before about four to six months, and whether to use them is a personal choice. If you are thinking about it, talk to your health visitor or doctor first. Most babies develop more settled sleep gradually, whatever you choose.

When to get advice

• Your baby has a fever, rash or is feeding poorly, or seems unwell
• Your baby snores loudly, pauses in breathing or breathes with effort at night
• Your baby is not gaining weight as expected
• You are exhausted or low in mood. Our guides on sleep for new mums and on baby blues and postnatal depression can help, and so can your midwife or health visitor.

This content is for general information only and is not medical advice. Every pregnancy and every baby is different. Always talk to your doctor, midwife or paediatrician about your own situation, and seek urgent care if you are worried.