Your Baby At 3 Weeks: Developmental Steps At A Glance

When your baby turns 3 weeks old, you already have an exciting time behind you: Your offspring is developing social relationships with familiar caregivers.

Before baby’s first big growth spurt in week five, he or she already has an emotional memory. Sense of touch and smell are already fully developed. Colic may occur during the first few weeks due to the immature digestive system.

Baby At 3 Weeks: How Is It Developing Physically?

In the first few days after birth, your baby will initially lose weight. Don’t worry, this is a normal development and is due to the fact that babies first excrete more than they can take in food. After the first 14 days, your offspring should have regained its birth weight.

From the third week, the weight starts to increase and your baby gains about 150 to 200 grams per week. If your baby cries a lot at the moment, rhythmically tightening his little legs, it could be colic.

When your baby is 3 weeks old, he is about 47 to 60 centimeters tall. The romper fits best in sizes 50 to 56. In the third week, the first big growth spurt of the baby is already imminent. This usually begins in the 5th week of life.

Learn more about the growth sp urt in babies and the development in the area of reflexes, motor skills and sensory perception.

Your Baby At 3 Weeks: Motor Skills And Reflexes

Your offspring is born with a variety of early childhood reflexes. These help him to find his way in the world “out there” and serve as self-protection. One of the innate reflexes is the sucking reflex.

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This can be triggered by putting a finger in the baby’s mouth. Your little one also has a grasping reflex. This helps him to hold onto objects or fingers automatically.

After about three to four weeks, many babies are already able to lift their heads for a few seconds in the prone position. Your child is fascinated by this new perspective. Even in a sitting position, some children can already hold their head for a brief moment. Another achievement in this phase of his life is turning his head.

When your baby hears something, it automatically turns its head in that direction. After the growth spurt of the baby from the 5th week, your baby develops rapidly in the fine and gross motor area.

How Your Baby’s Senses Change

Even though it may not seem so in the first few weeks, all of your baby’s senses are receptive and ready to learn. Your offspring is born with a fully developed sense of smell and touch. The senses of taste and hearing are also well developed.

Only the ability to see is still weak at the beginning. After the baby’s growth spurt in week five, the senses continue to develop rapidly.


When your baby is born, it can already see. However, his perception of his environment is still hazy and blurred. At first, it can only focus on objects that are 20 to 30 centimeters away. Beyond a range of 30 centimeters, your little darling cannot recognize much.

Your offspring also cannot perceive colors in the first weeks of its life. The color cells in the back of the eyes are not yet fully developed. This is also the reason why your baby prefers light and dark tones at the beginning.

Only after about one month is your baby able to perceive the brightness and intensity of colors. During this time, your offspring will also gradually begin to fixate on certain points with their eyes.

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Your baby’s hearing is already well developed at birth. After three weeks, the baby can already recognize your voice and those of other caregivers without any problems. It also turns its head in the direction from which it hears sounds.

In the coming months, your baby’s hearing will become more and more refined. Talk to your baby from the beginning and make sounds with rattles and bells to further develop your baby’s sense of hearing.

Smell And Taste

Your baby is 3 weeks young and already has a fully developed sense of smell since birth. Scents act directly on the limbic system and do not first have to pass through the cerebral cortex of the brain, as is the case with visual, acoustic and haptic stimuli.

The sense of smell is closely linked to our emotions and drives. It helps your baby find its mother’s breast after birth. This smells just like the amniotic fluid. Your offspring’s sense of taste is also already well developed. Shortly after birth, the baby already has fine taste buds.


Your child is born with a fully developed sense of touch. The tactile sense develops from the 5th week of pregnancy as one of the first senses ever. The sense of touch in the lip and tongue area is particularly well developed, which is why children prefer to use their mouths to explore objects in the first years of life.

How Does It Develop Mentally?

In the first weeks of life, your baby is mainly occupied with sleeping and eating. The baby’s first big growth spurt is not until the 5th week.

Nevertheless, he has already made amazing progress in his mental development: he has formed a strong bond with you and already has an emotional memory. You can also look forward to your baby’s first sounds soon.

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Emotional Development Of Your Baby At 3 Weeks Of Age

Although the first big growth spurt of the baby is still to come, your offspring has already learned a lot at three weeks. He or she is able to express basic emotions such as fright, squirming and curiosity. It is also building a strong emotional bond with you.

The little offspring needs a lot of closeness and security now. This basic security is important so that your baby can later develop a stable personality.

Baby 3 Weeks: Social Development And Communication

In the first few weeks, your baby is busy developing a social relationship with you and other caregivers. When your baby smiles, it is still unconscious at first. In what is known as a “reflex smile”, your offspring automatically pulls up the corners of its mouth during sleep or half-sleep.

Your baby’s first social smile is not expected until week 6, but some babies already begin to imitate blinking their eyes or sticking out their tongues – an entertaining game for young and old alike.

Already after birth, your baby has communicative means to let you know how he or she is feeling. It produces its first sound signals or cries. After the baby’s first major growth spurt in week 5, it begins to make its first throat, palate and throat sounds.

Interact With Your Baby And Nurture Him Through Play

In week three, there are many things you can do to support your baby through play. However, do not overtax your offspring. At the moment, your baby is surrounded by many new sensory impressions that he or she must first process.

Train Attention

Take a black and white object and hold it directly in front of your child. This color combination arouses your baby’s interest in the first few weeks. Once you have gained your baby’s attention, slowly move the object in one direction.

Let your baby follow the object with his eyes. Then change the direction.

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Tactile Travel

Stroke your baby’s body parts with different materials such as a cloth and feathers. This trains your baby’s body awareness.

Hearing Training

Make sounds with a bell or rattle from different directions. Your baby will turn his head in the appropriate direction. This trains hearing and mobility.

Baby 3 Weeks: Colic

Some babies cry a lot in the first months of life. If your offspring pulls its legs rhythmically, it could possibly be colic. If your baby suffers from colic, he or she will have abdominal pain and flatulence.

The baby’s digestive system, which is not yet fully developed, is probably to blame for the colic. Your baby may be ingesting certain foods through breast milk that he or she is not able to tolerate. If your baby drinks too quickly, this can also cause painful colic.


The first major growth spurt in babies takes place from the fifth week. Nevertheless, your child has already made amazing developmental steps. He gains about 150 to 200 grams per week and is between 47 and 60 centimeters tall. Since the digestive system is not yet fully developed, colic can occur now.

In the first few weeks, the infant’s reflexes serve to protect itself. These only move into the background in the following months. Your baby is already able to turn its head and may be able to lift its head for a short moment in the prone position.

The senses of touch and smell are fully developed at birth. Hearing and sight are now developing steadily. Even before the baby’s first major growth spurt, your little one has developed an emotional memory.

It also builds social relationships with you and other familiar caregivers. It can express cornering, curiosity and fright. In this phase, it is important to create a so-called “primal security”. This will help your little one develop into a stable personality later on.

The best products for you and your baby.

Baby monitor

With a baby monitor, you can use your time flexibly, sleep peacefully at night and still know at all times that your baby is doing well.

Nursing pillow

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Diaper bags

A diaper bag offers you a lot of storage space, so that you have everything you need for your baby on the go - from the changing pad to the bottle.


A pucksack gives your baby the feeling of security, like in the womb, and thus supports a peaceful and restful sleep.

Bicycle trailer

Bicycle trailers can be used in combination with a baby seat shortly after birth. They are not only safer than child seats but also more comfortable.


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Radiant heater

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Extra bed

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