1-3 Months Old Baby Development

1- to 3-Month-Old Developmental Milestones

Have you noticed how your baby’s tiny fingers curl around yours or close into fists? Or how your little one startles at a loud noise? Your baby was born with these and other reflexes, which will get less noticeable as your baby hits their 1-3 month milestone.

Doctors use milestones to tell if a baby is developing as expected. There’s a wide range of what’s considered normal, so some babies gain skills earlier or later than others. Babies who were born prematurely may reach milestones later. Always talk with your doctor about your baby’s progress.

1- to 3-Month-Old Areas of Development

How Much Will My 1- to 3-Month-Old Grow?

While all babies may grow at a different rate, the following indicates the average for boys and girls 1 to 3 months of age:

• Weight: average gain of about 1.5 to 2 pounds each month
• Height: average growth of about 1 inch each month
• Head size: average growth of about 0.5 inches each month

Your baby can go through periods of increased hunger and fussiness. This increase in hunger means your baby is going through a period of fast growth (a growth spurt). If you breastfeed, you might find your baby wants to eat more often during certain times of the day, and sometimes, every hour. This is called “cluster feeding.” Formula-fed babies may want to eat more often or will drink more formula than usual during feedings.

As your baby reaches 1 to 3 months, you’ll start to learn the signs that tell you that your baby is hungry or when your baby is full. You will know your baby is hungry when they seem restless, cry a lot, stick out their tongue or suck on their hands and lips. You will know your baby is full when they are no longer interested in feeding or falls asleep at the end of a feeding session. Remember, babies’ tummies are very small, and they need to be burped after feedings to release gas that can cause discomfort.

During your 1 to 3 month checkups, the doctor will measure your baby’s weight, length and head circumference and track their growth on a standardized growth chart. Note, there are different charts for boys and girls. Your baby might be large, small or medium-sized compared to the growth chart. As long as this growth pattern stays consistent over time, chances are your baby’s progress will be just fine.

If your baby is born prematurely, keep in mind that growth and development should not be compared with that of a full-term child. Preemies will need to be followed more closely and may need to be weighed more often during the first months to make sure they are growing properly.

What Can My 1 to 3-Month-Old Baby Do at This Age?

As your baby begins to grow, you will notice new and exciting abilities that develop. Babies at this age begin to relax the tight muscle tone of newborns and begin extending their arms and legs more. While babies may progress at different rates, the following are some of the common milestones your baby may reach in this age group:

• Some of the newborn protective reflexes begin to disappear
• Neck muscles become stronger, head bobs then is held erect
• Turns head from side to side when placed on abdomen
• Brings hands or objects to mouth
• Looks at hands
• Follows light, faces, objects
• Listens to sounds
• Opens and closes hands
• Holds, then drops a rattle or other object
• Active leg movements

At the end of 3 months:

• Raises head and chest when placed on abdomen
• Beginning to reach hands to objects, may bat at hanging object with hands

What Can My 1- to 3-Month-Old Baby Say?

It is very exciting for parents to watch their babies become social beings that can interact with others. While every baby develops speech at their own rate, the following are some of the common milestones in this age group:

• Begins to imitate some sounds (coos, vowel sounds)
• Cries become more purposeful and are different for hunger, fatigue and other needs

What Does My 1- to 3-Month-Old Baby Understand?

A baby’s understanding and awareness of the world around them increases during this time. While babies may progress at different rates, the following are some of the common milestones in this age group:

• Knows familiar voices, especially of their parents
• Smiles in response to others
• Responds to social contact, may coo
• Moves arms, legs, body in rhythm with other’s voice

What Can My 1- to 3-Month-Old Baby See?

Babies at this age can focus on shapes that are close by but see distant objects as blurry because they are nearsighted. As babies grow, their eyesight improves. By the end of 3 months, they can follow a moving object, are more interested in shapes and patterns and can spot familiar faces, even at a distance. Human faces are one of their favorite things to look at, especially their own face or a parent’s face. Installing a baby-safe crib mirror at your baby’s eye level can be great for development at this age.

Your baby’s color vision is also developing at 1 to 3 months, so brightly colored wall hangings or toys will help develop your little one’s ability to distinguish color. Soft pastel colors, though, are hard for a baby to distinguish — something to keep in mind when buying toys and books.

What Can My 1- to 3-Month-Old Baby Hear?

Your baby has been hearing sounds since way back in the womb. Mother’s heartbeat, the gurgles of her digestive system, and even the sounds of her voice and the voices of other family members are part of a baby’s world before birth.

Once your baby is born, the sounds of the outside world come in loud and clear. At 1 to 3 months, your baby may startle at the unexpected bark of a dog nearby or seem soothed by the gentle whirring of the clothes dryer or the hum of the vacuum cleaner.

Your baby loves to hear your voice, so talk, babble, sing and coo away. Take special advantage of your baby’s own “talking” to have a conversation. If you hear your baby make a sound, repeat it and wait for them to make another. You are teaching your baby valuable lessons about tone, pacing and taking turns when talking to someone else.

Babies this age seem to respond best to a higher-pitched voice, which is why most people naturally raise the pitch of their voices and exaggerate their speech when talking to a baby. This is fine — studies have shown that “baby talk” doesn’t delay speech development. In fact, responding to your baby encourages speech. Feel free to mix in some regular adult words and tone with the baby talk. It may seem early, but you’re setting the stage for your baby’s first words.

Besides voices, your baby will probably enjoy listening to music (play a variety of styles) and may be fascinated by the routine sounds of life as well. Keep your baby nearby as you rattle pans while making dinner and let them sit in a baby seat within earshot of older siblings laughing and playing. Baby rattles, musical mobiles and toys are other good ways to stimulate your baby’s hearing.

Your newborn probably had a hearing screening before being released from the hospital. If not, or if your baby was born at home/a birthing center, it’s important to have a hearing screening as soon as possible. Most children who are born with a hearing loss can be diagnosed through a hearing screening.

How Long Should My 1- to 3-Month-Old Baby Sleep?

Just when you think that getting more shut-eye is a far-off dream, your baby will begin to sleep longer stretches at night. As a baby’s sleep cycle gets closer to yours, your baby may be feeding less often at night. At this stage, “sleeping through the night” is considered to be a stretch of about five to six hours.

Babies at this age are more awake, alert and aware of their surroundings during daylight hours, so they’re more likely to be tired at night and sleep. Infants up to 3 months old should get 14-17 hours of sleep over a 24-hour period. Many will have settled into a daily sleep routine of two or three naps during the day, followed by a longer “sleeping through the night” stretch after a late-night feeding.

Check out our healthy sleep for babies to get more info.

How Can I Help Increase My 1- to 3-Month-Old Baby’s Development And Emotional Security?

Young babies need the security of a parent’s arms, and they understand the reassurance and comfort of your voice, tone and emotions. Consider the following as ways to foster emotional security of your newborn:

• Hold your baby face-to-face and make eye contact.
• Talk to your baby with a soothing, animated voice throughout the day while dressing, bathing, feeding or playing with your baby.
• Sing to your baby.
• Give your baby rattles and soft toys with different sounds.
• Let your baby hear different sounds (for example, wind chime, ticking clock, soft music or music box).
• Show your baby bright pictures of black and white images.
• Hang a mobile with bright objects above your baby.
• Call your baby by name.
• Hold your baby during feedings and provide comfort when he or she is distressed and cuddling when happy.

Reviewed by Dr. Vivi Tran, Los Alamitos Pediatrics, CHOC Primary Care – May 2021