Development In Babies From Birth To 3 Months: What You Need To Know

Your baby’s life from birth to 3 months will be filled with a lot of activity. In other words, your baby will be doing a lot from 3 months, some of which you may not expect.

All these activities are largely determined by their developmental milestones, which most babies reach around the same age.

However, it doesn’t negate the fact that each infant develops in their own way. Your baby will develop and mature at their rate, and that’s something you ought to be prepared for.

One of the ways to prepare is to understand what to expect at the corresponding milestones, and the things to expect at those milestones are precisely what this guide is about.

Just a reminder: premature babies will not likely reach all their developmental milestones on time.

Baby Growth And Development From Birth To 3 Months

mother holding her baby's feet and smiling
Image Source: iStockphoto/AleksandarNakic


Physical Development

Newborns typically weigh between 5 pounds 8 ounces (2,500 g) to 8 pounds 13 ounces (4,000 g), although premature newborns regularly weigh less.

In the first few days, newborns usually lose around 10% of their birth weight, but they naturally regain it within two weeks.

The average resting heart rate ranges from 70 to 190 beats per minute.

Motor Skill Development

Newborns move as a result of stimulation.

Demonstrates several infantile reflexes, including:

The infant’s rooting reflex causes them to suckle whenever a breast or bottle is put in their mouth.

When startled, the child exhibits the Moro reaction, which leads them to thrust out their arms and legs.

The infant’s arm on one side will straighten, and the other will bend due to the asymmetrical tonic neck reflex, activated when the head is rotated to one side.

The infant will grab a finger placed in their palm and curl their toes when the bottoms of their feet are touched due to the palmar grasp reflex.

Cognitive Skills

When silent and vigilant, the baby follows faces and focuses briefly on bright objects in front of the face.

Emotional Development

Soothed and comforted by parental voices and touches.

Ability to self-soothe when upset. Baby keeps a constant state of alertness.

Communication Skills

Baby can turn head in the direction of speakers and sounds.

Crying is used to express needs, and crying is stopped after those needs have been addressed.

Development At One-Month-Old

At first, it might appear that your infant only feeds, sleep, cry, and change diapers. He’ll be much more attentive and responsive by the end of the first month.

Peaceful baby lying on a bed and sleeping
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Physical Development

Baby typically gains approximately 2 pounds (910 g) and grows between 1 and 1.5 inches (2.5 and 3.8 cm).

Motor Skill Development

Baby’s fists remain firmly closed, and legs and arms can move equally on both sides.

They’re now capable of briefly holding the head up when lying flat.

A jerky arm thrust is used, and they bring hands up to the mouth and eyes.

They can now turn their head from side to side when lying flat.

If the head is not supported, it falls backward.

Reflexes in infants are powerful.

Cognitive Skills Development

At this stage, babies stare at things while they are in front of their faces, especially those colored brightly; they become capable of face tracking.

Sensory Development

Babies start focusing on objects between 8 and 12 inches (20 and 30 cm) distant. Their eyes may stray and even cross.

They prefer patterns in superb contrast and black & white but favor the human face over all other patterns.

Their ability to hear is complete.

They prefer sweet scents and dislike those that are bitter or acidic.

They recognize the smell of breast milk and enjoy gritty and gentle sensations but dislike being handled roughly.

Communication Skills Development

Babies can now be startled by sudden loud noises; they become capable of making sounds other than weeping and the ability to distinguish parents’ voices.

Emotional Development

When distressed, they react to consolation from parents, notice nice sounds, and become alert.

Development At Two Months Old

Image Source: iStockphoto/AleksandarNakic

Physical Development

Baby grows between 1 and 1.5 inches (2.5 and 3.8 cm) and adds roughly 2 pounds (910 g) at a rate similar to the previous month.

Heart rate falls between 80 to 160 beats per minute and remains in that range until the child is about a year old.

Motor Skill Development

Now, your baby’s neurological system has some degree of development. Voluntary movements are starting to replace some neonatal reflexes. More fluid and wiggly movement results from increased muscular control. What else can you anticipate?

Lifting heads during tummy time: Most infants of this age can lift their heads when lying on their stomachs. Giving your infant regular tummy time is a fantastic method to support her in strengthening her neck and trunk.

Some babies cry when put on their stomachs, but they typically get better after a few times. It helps to have something captivating in front of them, like mom’s face, to motivate them to elevate their heads.

Your infant may attempt to push up from a supine posture even if they are still too young to crawl.

Hand-to-mouth: Your kid may wave his arms more frequently when happy during these weeks. His hands will draw his attention more and more. He could spend a lot of time attempting to move things in front of him so he can view them.

He could eventually move them to his lips after numerous attempts. His limited finger movement means his hands will probably still be clasped in tiny fists. He might find solace in sucking on them.

Communication Skill Development

They can now babble and coo, turn their head to listen to noises and sounds, smile when spoken to, and pay attention to those speaking.

Emotional Skills Development

Ability to relax quickly by sucking on their fingers, they smile happily.

Cognitive Skills Development

They start paying attention to faces, following objects with eyes, recognizing people from a distance, and becoming fussy when an activity does not change.

Development At Three Months Old

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Physical Development

Baby adds 1.5 to 2 pounds (680 to 910 g) and typically grows 1 to 1.5 inches (2.5 to 3.8 cm) in height.

Baby’s entire physique may now appear to be more at ease. His hands won’t be constantly clenched into fists.

He could even amuse himself by slowly opening and closing them. He’ll also take pleasure in more vigorously kicking his legs, now straightening out from their newborn position of being pulled up.

He might soon be able to kick himself over from his stomach to back as his kicks get stronger. While most infants can still not roll from their backs to their stomachs, some may start to do so at this age.

Never leave your infant unattended on any furniture where they could roll over.

Social Development

At this stage, the baby establishes a friendly smile and uses the face and body to communicate and convey more.


Image Source: iStockphoto/bb-doll

Remember that every infant develops at its rate, and developmental milestones can vary greatly.

Consult a pediatrician or other healthcare professional for advice and assistance if you are worried about the growth or well-being of your infant.

Your baby’s health and growth are primary priorities during these crucial early months.

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