4 Months Milestones

Four months is often described as the "golden age" of babyhood. Your baby is more alert, more social, and more interactive than ever. They are laughing, babbling, reaching for toys, and lighting up when they see you. This is also a time when you really start to feel like you are getting to know your baby's personality. Some babies are more active, some are more observational - there is no right way to be a baby. Sleep patterns may be starting to consolidate (though plenty of babies are still waking at night, and that is okay). If your baby was premature, remember to consider their adjusted age when looking at milestones. As always, talk to your pediatrician if anything concerns you - they are there to help and will never judge you for asking.

Holds head steady without support

CDC WHO

When you hold your baby upright, their head stays steady and does not wobble or flop.

What it looks like

When you hold your baby against your shoulder or sitting upright in your lap, they keep their head centered and steady. They can look around without their head falling forward or to the side.

Typical range

2 moavg 3 mo4.5 mo5 mo

When should I worry?

This is normal

Most babies have steady head control by 3 to 4 months. You will notice they can sit in a supported position and look around freely. Tummy time has been building up to this - all those little push-ups paid off.

Mention at next visit

If your baby's head still wobbles or flops when held upright by about 4 to 5 months, mention it to your pediatrician. They can assess muscle tone and neck strength.

Call your doctor

If your baby had steady head control and suddenly loses it, or if their head always falls to one side and they cannot straighten it, contact your pediatrician right away.

Pushes up on elbows during tummy time

CDC

When on their tummy, your baby props themselves up on their elbows and lifts their chest off the floor.

What it looks like

During tummy time, your baby pushes up onto their forearms, lifting their head and chest well off the surface. They may look around in this position and seem proud of their new vantage point. Some babies can hold this position for a minute or more.

Typical range

2 moavg 3.5 mo5 mo6 mo

When should I worry?

This is normal

This "mini push-up" is an important stepping stone toward crawling. It builds upper body strength and gives your baby a new view of the world. Babies who get regular tummy time tend to achieve this earlier.

Mention at next visit

If your baby cannot push up on their forearms at all by about 5 months, discuss it with your pediatrician.

Call your doctor

If your baby seems to have significant weakness in their arms or cannot bear any weight on them, contact your pediatrician for evaluation.

May begin to roll from tummy to back

CDC WHO

Your baby might surprise you by rolling from their tummy onto their back during tummy time.

What it looks like

While on their tummy, your baby may push up, shift their weight to one side, and topple over onto their back. It may look accidental at first. Some babies do it once and then not again for weeks - that is normal.

Typical range

3 moavg 4 mo6 mo7 mo

When should I worry?

This is normal

Rolling from tummy to back is usually the first direction babies learn to roll, because pushing up on their arms creates the momentum. Not all babies roll at 4 months - many do not roll consistently until 5 to 6 months. Both are normal.

Mention at next visit

If your baby shows no interest in rolling and cannot shift their weight to either side by about 6 months, bring it up with your pediatrician.

Call your doctor

If your baby seems unable to move one side of their body, or if you notice a sudden change in their ability to move, contact your pediatrician.

When to Talk to Your Doctor

Red flags to watch for

If you notice any of the following, contact your pediatrician. These signs do not necessarily mean something is wrong, but they are worth discussing with a professional.

Does not watch things as they move
What to do
Let your pediatrician know. Visual tracking should be well-established by this age, and a vision check is recommended.
Does not smile at people
What to do
If your baby still has not shown social smiles by 4 months, your pediatrician should evaluate social and emotional development.
Cannot hold head steady
What to do
Head control should be well-developed by 4 months. Discuss with your pediatrician - they may recommend a physical therapy evaluation.
Does not coo or make sounds
What to do
If your baby is not making any sounds besides crying, ask your pediatrician about a hearing evaluation and speech-language assessment.
Does not bring things to mouth
What to do
Bringing hands and objects to mouth is expected by this age. Let your pediatrician know if this is not happening.
Does not push down with legs when feet are placed on a hard surface
What to do
Your baby should push down with their legs when held in a standing position on a firm surface. If they do not, mention it to your pediatrician.
Has difficulty moving one or both eyes in all directions
What to do
Contact your pediatrician or a pediatric ophthalmologist for evaluation of eye movement.