Child Development Guide: 1 to 3 Months - September 2026

Your baby has now made it through their first 28 days. Between the ages of 1 to 3 months old, they are no longer a newborn but an infant. This period is marked by rapid development. Your little one is still too young to walk around or learn new words. But they are quickly learning about the world around them. If you are a new parent, it’s important to know all the milestones that your baby goes through at this stage. This includes physical, cognitive and emotional development. Now that they are older, all three of these slowly begin to overlap as their motor skills, social interactions and vocalisations improve. Here’s what you can expect for your baby’s progress between the ages of 1 to 3 months old. Physical Development At 1 to 3 months old, your baby should be gaining around 4 to 8 kilograms and growing about 1 to 3 inches. However, your little one’s physical development encompasses so much more than just their height and weight. Changes in their sleeping habits, their motor skills and their mouthing. Here’s what to expect. Sleep Cycle Your infant is now sleeping a little less during the day than they were when they were newborns. As a general rule, infants do not sleep for 10 or more hours straight like adults. Their sleep is broken up into 3 to 4-hour intervals. But on average, infants sleep between fourteen to seventeen hours of sleep per day (non-consecutively). However, between 1 to 3 months, they are able to sleep through the night but not for long. They often wake up two or three times during the daytime. Your baby is now able to fall asleep for the night as soon as they finish their evening feeding. Motor Skills Your baby is beginning to test and experiment with their motor skills at this point. This includes moving their limbs and wiggling. By the end of their third month, your baby’s neck and upper body muscles should be well-developed and strong enough. They should be able to raise their heads and chests when you put them on their stomachs. This is known as the ‘Landau Reflex’ They are now also able to stretch and kick their legs and move around. In fact, most of the time they spend awake will be dedicated to physical activity. They’ll turn their head from side to side, they’ll clasp their hands together, and even reach for and grasp objects nearby. Their rooting and sucking reflexes are well-developed at this stage. However, their swallowing reflex and tongue movements are not. This is why they’re still drooling and are unable to move food to the back of the mouth. Mouthing Your baby is now able to bring their fingers and hands to their mouths. This is a milestone known as ‘mouthing’. Thumbsucking is also considered an aspect of this milestone as does putting objects into their mouth. This behavior is important for hand-eye coordination and also serves as a self-soothing mechanism. Your baby also licks and bites things as a way to explore the world around them. Some people believe that mouthing is a way for the baby to prepare for solid food. That said, other studies suggest that mouthing may actually be a precursor to language development and vocalisation. But more on this later. Cognitive Development Early motor skills are not just physical milestones; they play a huge role in cognitive and behavioural development in later childhood as we will soon find out. In fact, research indicates that the quality of your baby’s movements at three months old is strongly linked to cognitive performance later in childhood. Sensory Responses At 1 to 3 months old your baby should have more advanced sensory abilities. When they were newborns they were mostly absorbing sensations from their surroundings. Now they are able to respond to their stimuli from their surroundings: particularly sound, sight, smells. For example, they are able to track moving objects with their eyes. While basic, this shows that their visual skills are getting better. As their memory capabilities grow, they are also now able to recognise familiar faces, objects and even sounds. When they hear their caretaker’s voice for instance, they are able to turn their heads towards the source of the sound (sound localisation). If they are crying, they will stop if someone they know, like a parent, talks to them. They also respond to other noises like singing, chanting, music, conversations, pet noises and loud sounds. They are now also able to recognise the smell of their caregivers and can respond to gentle touch by using distinct facial expressions. Vocalisation Your little one is not just learning to react to sounds. They are now beginning to make their own little noises called ‘vocalisations’. This is a positive progress in their language development. They are now able to make simple noises such as babbling, gurgling, squealing and cooing when spoken to or smiled at. Some babies are extra ‘talkative’. These simple sounds include ‘ah’, ‘eh’ ‘uh’ and other similar noises. They can also imitate some vowel sounds produced by others. While these noises are not actual words, ‘baby talk’ is how infants first learn how to make sounds with their vocal chords. Your little one can even laugh out loud when tickled or when they see something particularly funny or interesting. This is part of their socio-emotional progress as well where they are able to make sounds as a response to their parents’ talking to them or to other external stimuli in their environment. Emotional Development Emotional development in the first three months overlaps with their sensory responses. Your little one is now able to interact with you through basic emotional expressions. They can respond to your voice or just by seeing your face, or the face of someone familiar like another family member (siblings, relatives, etc). As such, this is the period where they begin to develop what is known as a ‘social smile’. Social Smile The first socio-emotional milestone around 1 to 2 months of age is that your little one is now able to smile. This is a social response to their parents’ or caregivers’ voices. Your baby is also starting to cry a little bit less at this stage as they begin to learn how to self-soothe (i.e. thumbsucking). They are able to regulate their emotions better and respond to gentle calming by a caregiver. While they still generally use crying to get your attention or to express their needs, they can now laugh as well when they are happy. Social Interactions At 1 to 3 months old, babies start to enjoy being cuddled by their parents. Social time together through familiar and constant routines are soothing to them. So it’s important to have regularly scheduled bath time and diaper changes. You will find that your little one is now enjoying playtime with others. They can even mimic the facial expressions and movements of others. When they are alone, they are able to entertain themselves by playing with their fingers and toes. It is therefore important that parents and caregivers pay the utmost attention to their little ones at this stage. Between the ages of 1 to 3 months, babies need a lot of stimulation and social interaction to keep their brains active. Celebrating New Milestones Parents and caregivers play an important role in supporting their little one’s development during these early months. How often or how little you interact with them can make all the difference in their future development. Remember to engage in activities that promote their growth. This includes supervised tummy time to help strengthen their neck and shoulder muscles and talking or even singing to your baby to jumpstart their language development and auditory processing. It’s also good to maintain eye contact and respond to your baby's cues to promote bonding and social engagement. While most babies reach these milestones at the appropriate ages, it’s also important to understand that each child is different. Remember to give them plenty of time to reach these milestones at their own pace. However if your baby is taking longer to reach their developmental milestones, it’s probably a good idea to talk to your paediatrician to rule out any delays or disabilities. This is why learning about childhood development is important for any caregiver or parent. With proper screening and prevention, any child can have a bright future. Even if they may be a bit slower in their journey than their peers. But no matter what, you should still celebrate those milestones no matter how small as they are all hallmarks of a healthy, happy baby who is more than eager to explore the world. Disclaimer: The information provided in this article is for informational purposes only and should not be considered as medical advice from Mamahood. For any health-related concerns, it is advisable to consult with a qualified healthcare professional or medical practitioner. For more insightful stories and parenting advice, stay tuned to Mamahood Singapore!

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