3 Week Old Baby Development

image001The third week of life for your baby will be a welcome sight for you, as he would now remain more awake and alert that he has been throughout the first few weeks of his life. By now, you would have definitely learnt how to change diapers and would be familiar with many things about the baby’s feces. You would have wondered how your baby is capable of creating so much smelly waste. It is highly likely that you might have visited the pediatrician by now and would have settled in to a routine too.

At the three week stage, it is necessary to take the baby for a visit to the hospital. This well visit as it is called would include measurement of the baby’s height and weight as well as checking of his lungs and heart. The physician might use his stethoscope for this purpose, so don’t get frightened if you see him using it.

How Is a 3-Week Old Baby Developing?

1. Weight and Height

The development cycle of each baby is different from the other so it is highly likely that one baby grows quickly while another one might do so rather slowly. The development and growth standards have been designed to catch any growth problems that they baby might have at an earlier stage. For instance, the weight measurements are for checking the baby’s digestive system.

The usual growth standards for height and weight do not stand true for premature babies. Such babies have two different ages; actual age and an adjusted age. These ages are calculated from their actual birth date and due date respectively. Thus, the standards for weight and height for premature babies must be measured using their adjusted age.

Babies' average weight and height (WHO child growth standards)



Weight (kg)

























2. Physical Development

A 3-week old baby might:

What They Can Do


Developed a more systematic eating and sleeping pattern

You would also have become more aware of the baby’s needs and would have learnt what to give him at what time by now.

Stay awake more often

He would keep looking at your face after finishing a meal or taking a bath and will keep his eyes fixed on you while you are talking to him.

Start responding to you by cooing

It shows that he is excited to hear you. These sounds are the baby’s attempt at conversation so try and respond to his coos as often as possible.

Seem tired at night

This is a sign that his nervous system is maturing each day and he has started exploring his surroundings more which is the reason why he needs to sleep at night to regain his energy levels.

Gain more head control

Although he would still require a lot of support, he would not seem so delicate and fragile any more. At this stage, keeping him a front pack, close to you, is a thing that he would like.

Obtained more strength in his upper body

So much so that when he is put on his tummy, he would start getting his head up. You must start putting him on his tummy more so that he can make his shoulders strong. However, the baby must continue to sleep on his back.

Gained control of his eyes

He would now be able to watch his hands which are not under his control flail in front of him and observe the objects that are lying around him.

Watch this video to learn more about a 3-week old baby’s development:


How to Take Care of a 3-Week Old Baby

1. Feed Your Baby Properly

Feeding is a tiring process for a child who is only three weeks old. This is why after a feed your child will most likely fell asleep. Don’t be surprised if you find him falling asleep during a feed. Moreover, the baby might start demanding regular feeds at this stage of his life. Since his stomach cannot hold a lot of milk, he would want to be fed at least ten times throughout a day.

2. Sleep Pattern and How to Cope with It

In the third week, the baby would want to sleep after each feed. He might also fell asleep while you are holding him in your arms. Properly fed babies tend to sleep more easily and peacefully then those who are hungry. If you baby isn’t sleeping after a feed then it is best to consult your doctor and find out is anything is wrong. When putting a baby to sleep, make sure that he is wrapped in a secure blanket and is lying on his back.

3. Spend Some Tummy Time

During the third week, it is a good idea to increase the tummy time of the baby. You can start by putting a mirror under the baby while he is lying on his tummy and get him to move his eyes from side to side using light or a toy. However, during this tummy time make sure that the baby is attended to at all occasions. If the baby becomes restless while lying on his tummy, lay him on his back and allow him to sleep for a while or get him involved in some other activity.

4. More Tips for Taking Care of Your 3-Week Old Baby

  • Change their nappies

Changing of nappies is one task that you would have to perform over and over again. Thus, it is best to designate a place where the task of nappy change is going to take place. Make sure that the place is clean and has everything that you need present close at hand. The used nappies might have to be disposed of or washed. In either case, see to it that you don’t have to strain yourself too much.

  • Take care of the belly button

By the third week, the umbilical cord stump will have separated from your baby’s belly but the area around his belly button might still be a little raw. Try to keep this area clean and air dry it regularly as it will speed up the healing process.

  • Always stay clean

Bathing is extremely important for a baby, as it can help him in relaxing and getting a good night’s sleep. However, this does not mean that you have to bathe him on a daily basis. When bathing a baby might feel unsecure if he is naked. So, it is a good idea to keep a washer on his tummy while bathing which is going to make him relax and feel a lot safer.

  • Pay attention to their bowel movement

Bowel movements vary from baby to baby and depend mostly on their diet as well as their respective digestive systems. Breastfed babies are likely to have a bowel movement after completing a feed while a baby that uses bottle milk might not have more than 3 bowel movements throughout an entire day. If a baby being formula fed has not had a bowel movement for 2 days or if a breastfed baby hasn’t passed stool for 4 days then they should be taken to a doctor immediately.

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