Your 21 Week-Old Baby – Development, Milestones & Care

A mother playing with her baby

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At this point, every day can bring about some exciting changes in your baby. It may be delightful for you to observe as your baby tries to pull himself into a sitting position or attempts to crawl. You may witness your baby responding to you or showing affection towards you. In a truly heartwarming moment, he may throw his cute little arms to embrace you and stretch out his arms to be lifted up. Most babies during this period start to imitate the actions and the words of the adults around th

A 21 Week-Old Baby’s Development

A 21 week-old baby

Your baby at 21 weeks old may display remarkable advances both physically and mentally. A 21-week old baby weight usually measures around 14 to 16 pounds. Baby’s hearing abilities and vision will continue to improve. He may look in your direction when you call out his name. He may also begin to show a range of emotions like enjoyment, pleasure, anxiety, irritability, and boredom.

[Also Read5 Months Old Baby Development]

Uneasiness due to separation from mother also starts to manifest around this time. Your baby may start crying when being passed on to someone else. If this is commonly happening with your baby, you may like to give adequate time to your baby to get familiar with strange people. You may hear your baby stay his first words- with any luck it will be a mama. Babies during this time try to duplicate the sounds that they mostly hear. To help your baby in this respect ensure that he is looking at your face when you speak with him so that he can watch the movements of your lips and then try and follow suit.

A 21 Week-Old Baby’s Milestones

Every baby develops at his own time and pace. So, the developmental milestones for each baby may be different. Some twenty-one-week old baby milestones can be:

  • The taste buds of the baby are more developed by now. He will be continuously putting things in his mouth.
  • Some babies will be sitting around now although most babies may still need certain support to sit up.
  • Your baby’s sight is constantly developing. He may be able to focus on a variety of objects even smaller and moving ones.
  • Your baby’s muscles are becoming stronger. He may be capable of easily rolling over to his side or flipping over to be lying on his belly.
  • Your baby may be adding new sounds to his typical babby babble like a gurgle or a squeak. He may also be repeating sounds that he gets to hear around him.
  • Your baby is likely to laugh or enjoy you making funny sounds or faces at them.
  • Some babies begin. Symptoms may include excessive drooling, swollen gums, heightened irritability.

[Also Read: 5 Months Old Baby Milestones]

Baby Feeding

You will be pleased to realize that your baby’s appetite is likely to increase. You may want to feed your baby in a quiet and peaceful environment as he is less likely to get distracted by his surroundings and may eat better. The feeding patterns of your baby may change during this spell. He may simply drift from feeding into a nap. You will also realize that the number of feeds can reduce as the baby may prefer to sleep his way through the day. Babies during this time can go for lengthier durations between feeds.

It is essential that you continue offering breast milk to your baby even if you decide to introduce solids in his diet. However, in most cases, breast milk or formula milk may be enough to meet the nutritional requirements of the baby at least for the time being. There is no urgency to introduce solids as yet. It is quite common for babies to cut back on their milk intake a little as they develop an extra preference for solids.

[Also Read: 5 Months Old Baby Food]


21-week old baby sleep patterns may start getting regular. Here are some of the key points about the sleeping patterns of 21 weeks old baby:

  • Your baby may not sleep throughout the night.
  • But you may discover that your baby is sleeping for longer hours during the night.
  • Most babies wake up during the night because of thirst and hunger. Usually, breastfeeding your baby should help him settle down and get back to sleep.
  • However, his naps may become consolidated during this stage. He is more likely to take chunkier naps (around 45 min) instead of frequent small naps through the day.
  • It may not be a good idea to feed your baby too much before sleep time in the hope that he sleeps throughout the night. Overfeeding can cause colic and may lead to added wakefulness.
  • Sleep regression in 21-week old infant is typical of this phase. If your baby has been sleeping well at nights but unexpectedly begins to experience recurrent night waking or develops napping issues, he may be undergoing sleep regression due to growth spurts.

[Also Read: 5 Months Old Baby Sleep]

A 21 Week-Old Baby’s Care Tips

Some of the 21-week old baby care tips are as follows:

  • It is sensible to opt for ground settings or mattresses to prevent likely falls as your baby is now capable of rolling or flipping himself over.
  • You may like to offer soothing and safe teething toys or rings to your baby in case he is teething.
  • It is also desirable to sterilize his other toys as he is likely to put them in his mouth.
  • Keep an eye on your baby when he is playing with small items or parts of toys that can come loose lest they turn out to be choking hazards.
  • Childproof your house and get rid of dangling cables or any other accessible objects that he is likely to pull down and hurt himself.
  • You should start cwith a soft damp cloth to get rid of any leftover food or milk in his mouth.
  • In case your baby is drooling too much keep a good supply of bibs handy.
  • To prevent diaper rash frequently change a diaper, clean the area properly and allow the baby to remain without diapers for some time every day.

[Also Read: 5 Months Old Baby Care]

Tests and Vaccinations

At 21 weeks your baby is actually between immunizations. In case you seemed to have missed any of your baby’s 4-month immunizations, you may want to schedule an appointment with your doctor on priority.

Games and Activities

You may notice your baby trying to raise his head while lying down or raising both his legs in the air while lying on his back. You may also see him taking the weight of his upper body entirely on his stretched arms or slide backwards when he tries to push himself. All these activities help the baby in further strengthening and toning his muscles. Even if your baby is simply rolling, he may be able to travel a lot of ground rapidly.

Most babies at 21 weeks begin to like entertaining themselves as they slowly start to discover their surroundings. Some bright coloured toys preferably something they can chew upon, musical toys, roly-poly toys can keep them entertained for long. Nevertheless, there are a few games that your baby may enjoy playing with you. You can engage your baby in easy repetitive games such as peekaboo which will help in developing his cognitive and verbal skills. Your baby can also develop a great attachment to a specific toy which he may use as a comforter.

[Also Read: 5 Months Old Baby Games and Activities]

When to Consult a Doctor

Your baby’s immunity is still not fully developed. Therefore, he may be vulnerable to common cold and flu. You should consult a doctor if your baby has a runny nose, a fever or he is consistently crying. Sometimes babies are prone to colic. It is always better to follow the mother’s instinct. Call your doctor if you feel something is amiss.

Spending time with a 21 weeks old baby can be quite exciting. Try and spend as much time bonding with your baby as possible. This is a wonderful age to enjoy the joys of motherhood!

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