By four months most babies have found their hands, smile at people they recognise, hold their head up steadily and are starting to laugh out loud. Many suddenly sleep worse: sleep is maturing and the baby wakes between sleep cycles. It is a phase, not a problem, and the variation between healthy babies is wide.
A four month old in a pram in Vasaparken on a Thursday morning: she is lying on her back, gripping a cloth book with both hands, pulling it to her mouth, dropping it, laughing at the dog walking past. Two weeks earlier she mostly lay there and looked. That is how it goes now: things happen in bursts, and every week something new may have arrived.
What happens with development at four months?
- Holds their head steadily, lifts head and chest on their arms when lying on their tummy
- Finds their hands, brings them to their mouth, grasps things placed in their hand and drops them without meaning to
- Follows objects with their eyes across the whole field of vision, turns towards sounds and voices
- Laughs out loud, babbles with vowel sounds and answers when you talk, like a conversation
- Recognises their parents and shows the difference between familiar faces and strangers
- Kicks hard, pushes off with their legs when held standing
- Starts rolling from tummy to back for some; others do not roll until six or seven months
All of this comes in a different order and at a different pace. A baby who rolls at three months is not ahead, and one who does not roll at five is not behind. BVC (the child health clinic every family in Sweden is enrolled in) follows development at each visit and looks at the whole picture, not at individual milestones. If you are worried, that is where to turn, not to a list on the internet, including this one.
Sleep at four months: why everything is suddenly different
Somewhere around four months, for some at three and for others at five, the structure of sleep changes. Newborns fall straight into deep sleep. Now the baby instead falls asleep through light sleep and sleeps in cycles of roughly 45 minutes to an hour, much like an adult. Between cycles the baby stirs, and if they fell asleep at the breast or in your arms they want the same thing again to drop off. This is what is usually called the four month sleep regression: more wake-ups, shorter naps, protests at bedtime.
What helps is boring but works: the same bedtime routine every evening, a dark room, less stimulation in the last hour, and now and then putting the baby down drowsy but awake so they get to practise falling asleep in their cot. Wait half a minute before going in when the baby grizzles; sometimes they drop back off. Sleep training that involves leaving the baby to cry is not advised at this age. For most babies it passes in a few weeks. Some sleep better afterwards, others keep waking every night until their first birthday. Both are normal, however unreasonable it feels at three in the morning.
| Sleep at four months | Roughly |
|---|---|
| Total sleep per 24 hours | 12 to 16 hours |
| Night sleep | 9 to 11 hours, with one or more wake-ups |
| Naps | 3 to 4 a day, from 30 minutes to 2 hours |
| Awake time between naps | 1.5 to 2 hours |
Food at four months
Breast milk or formula is still the whole diet. According to Livsmedelsverket (the Swedish Food Agency) you can offer tiny tastes from four months if your baby seems interested, but it is not necessary, and milk should not be reduced. At six months your baby should start on solid food properly. Four month olds are often distracted at feeds: they let go of the breast when someone walks past, look around, eat in short bursts. Feed in a quieter room if it becomes a problem. Vitamin D drops every day, from the first week until the child is at least two. Read more in Starting solids.
Play that suits this age
- Tummy time in several short sessions a day, with you on the floor at eye level
- A baby gym or things hanging within reach so she can bat at them and eventually grasp them
- Rattles, cloth books and teething rings to hold, taste and drop
- A plastic mirror on the floor. Four month olds love the baby in the mirror
- Peekaboo, songs with actions, reading aloud from anything at all, it is the voice that counts
- Talk about what you are doing, all the time. It feels silly and it is the best thing you can do for language
- No screens. Folkhälsomyndigheten (the Public Health Agency of Sweden) recommends no screen time at all under the age of two, and there is nothing in it for a baby
Other things that tend to come up around four months
- Drooling and everything in the mouth. Usually development, not teeth. The first tooth arrives for most babies between six and eight months, but anything from four to twelve is common. See Teething in babies.
- Evening fussiness eases. The classic evening unsettledness between three weeks and three months has usually passed or is on its way out by now.
- Vaccinations. The Swedish childhood vaccination programme has jabs at three and five months, with a BVC visit in between.
- A bald patch on the back of the head. From lying on their back. Completely normal, grows back once the baby sits up more.
- Slower weight gain. The first months are fast, now the curve flattens out. That is how it is supposed to look.
When to talk to BVC
- Your baby does not hold their head up at all at four to five months
- Does not smile at you and does not seek eye contact
- Does not react to sounds or to your voice
- Is very stiff or very floppy
- Uses almost only one side of their body
- Is not gaining weight
None of this necessarily means something is wrong, but these are things BVC wants to look at early, and it costs nothing to ask.
How we do it with our families
Nike looks after a four month old on Kungsholmen two mornings a week so that dad can work undisturbed. The session has the same shape every time: a bottle, a while on the tummy on the blanket with the mirror, a walk in the pram for the nap, home, bottle, play in the baby gym. When the naps got shorter last week she changed nothing, but noted on her sheet when he fell asleep and woke up, so the parents could see the pattern in black and white. That is often what reassures most: seeing that it is not chaos, just a new rhythm.
This text is general information and does not replace advice from BVC, your vårdcentral (local health centre) or 1177 (the national healthcare helpline). If you are worried about your child, call 1177. In an emergency, call 112.
Would you like a nanny who knows your baby, knows how things usually are and notices when something is different? Book a free first meeting with the nanny in your home.
Read more: Baby sleep from 0 to 6 months · Starting solids · Teething in babies · FAQ
Frequently asked questions
How long does the four month sleep regression last?
Usually two to six weeks, but it is not an exact science. Sleep changes structure around four months and the baby wakes between sleep cycles. Some babies find their way back to longer stretches at night after a few weeks, others keep waking every night well into the first year. Both are normal.
Should I start solids at four months?
You may, but you do not have to. Livsmedelsverket (the Swedish Food Agency) says tiny tastes can be offered from four months if the baby seems interested, but milk should remain the whole diet. At six months your baby should start on solid food properly. Feel free to wait if your baby shows no interest.
How much should a four month old sleep?
Roughly 12 to 16 hours per 24 hours, split between the night and three to four naps, but the range is wide. Awake time between naps is often an hour and a half to two hours. A baby who sleeps less but is content and growing does not have a sleep problem.
Is it normal for a baby not to roll at four months?
Yes. Rolling from tummy to back arrives for most babies somewhere between three and seven months, and from back to tummy often a little later. Babies who spend a lot of time on their tummy often roll earlier, but it says nothing about how development is going otherwise. BVC follows up at the visits.
Can I sleep train at four months?
Most advice, and 1177, advises against methods where the baby is left to cry alone before six months. What you can do now is keep a fixed bedtime routine, put the baby down drowsy sometimes, keep it dark and quiet at night, and wait half a minute before going in. Rarely is more needed at this age.