4 month old sleep: what to expect, common struggles and when to get help

Development at 4 months

According to the AAP, regular sleep cycles don’t appear until roughly 4 months. Once they arrive, brief wake-ups between cycles become more frequent, and a baby who used to be rocked all the way to sleep may now need that same help several times each night. This is what people call the 4-month regression — really a developmental step that tends to be permanent.

The CDC’s milestones by 4 months include pushing up onto the elbows during tummy time, holding the head steady, bringing hands to the mouth, chuckling, and moving or making sounds to hold your attention. Teething may begin as well; the AAP says it usually starts by about 4 to 7 months.

Many families reach out for help for the first time at this age. When a baby needs feeding or rocking at bedtime, they generally need it at every cycle. Actually Sleeping changes that through a plan Dr. Sam writes for your baby, bootcamp-style coaching before night one, and daily 1:1 check-ins. It isn’t cry it out, and it isn’t wait it out.

The number of naps is a typical pattern rather than a rule: some 4 month olds take three long naps, while others take four or five short ones.

The toughest parts for parents

• More waking after months of improved nights. Frequently a sleep-association issue surfacing rather than hunger — but check with the pediatrician before assuming either.
• Rolling in the crib. Babies flip onto their tummy and get frustrated, or practise rolling when they should be sleeping.
• Short naps. Single-cycle naps are extremely common at this age.
• Distracted feeds during the day that push calories into the night.

Keeping sleep safe at 4 months

• Continue placing your baby on the back for every sleep. Per the AAP, once your baby rolls in both directions — back to tummy and tummy to back — you don’t need to keep flipping them over, provided the sleep space is empty.
• Stop swaddling as soon as rolling attempts start. Use arms-free sleep sacks only, and never a weighted one.
• Continue room-sharing without bed-sharing, ideally for at least the first 6 months.
• If you’re still using a bassinet, plan the transition: according to the CPSC, bassinets aren’t intended for use past about 5 months or once a baby can push up on hands and knees.

Feeds during the night

Some 4 month olds still need one or more night feeds; others don’t. Your pediatrician makes that call, based on weight gain. Whatever plan you choose should work around those feeds rather than cutting them.

Reasons to check in with the pediatrician

• A fever over 101°F (38.3°C). Teething doesn’t cause a fever that high, according to the AAP, so it needs to be checked.
• Regular snoring, laboured breathing, or daytime sleepiness that seems like too much.
• A sudden increase in waking alongside fever, ear pulling, vomiting or poor feeding.
• Not yet holding the head steady or pushing up onto the forearms.

Next steps

For babies 4 months and older, the AAP advises putting them to bed drowsy rather than already asleep. Getting your particular baby there — without tears you aren’t comfortable with and without cutting feeds — is what generic advice skips. Actually Sleeping writes plans for exactly this stage and coaches naps until they are solid. Night feeds are handled according to your baby’s age, as set out in your custom plan. We guarantee that your baby will sleep 8–12 hours through the night within 14 days of consistent, correct implementation of your sleep plan. Parents who began at this very stage share their stories in our 4-month regression reviews. Related reading: the 4-month sleep change, the 4-month schedule, and the feed-to-sleep association. To talk through your baby’s nights, book a free consultation with Dr. Sam.