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21 Weeks Pregnant: Symptoms, Baby Size, and More

21 Weeks Pregnant Symptoms, Baby Size, and More

Dear mommies-to-be, are you excited for week 21? By now, your baby must be growing and developing rapidly in your womb. That should be great news!

You will also likely start noticing some new changes in your body as well. Let’s take a closer look at what’s happening to both you and your baby during this phase of your pregnancy. Read on!

Your Baby at the 21-Week Mark

Your Baby at the 21-Week Mark

Let’s find out how your baby is developing at 21 weeks:

Digestive System Starts Developing

At this stage, your baby’s digestive system is beginning to form. The intestines, which have been growing in the umbilical cord, are now starting to move into the baby’s abdomen. 

But that is only the beginning of a beautiful milestone! At 21 weeks pregnant, your baby will begin to swallow some amniotic fluid daily. 

This is necessary for their nutrition and hydration. So make sure you eat healthy as your baby gets a little taste of whatever you eat during this time.

Onwards, your baby’s digestive system will continue to mature throughout the rest of your pregnancy journey.

Blood Cell Formation Begins

Around 21 weeks, your baby’s bone marrow is beginning to produce red blood cells, taking over this important function from the liver and spleen.

Sleeping Position Established

By this week, your baby has also developed a sleeping pattern. You might start noticing periods of activity followed by periods of rest when the baby is still. 

However, with all that movement, I only hope your baby’s sleep also coincides with yours.

How Big Is My Baby at 21 Weeks?

At 21 weeks, your baby is approximately the size of a large banana. Your bundle of joy will measure about 10.5 inches (27 cm) from head to heel and weigh around 12.7 ounces (360 grams).

At 22 weeks onward, you’ll feel more pronounced movements as your baby continues to grow. It is important to continue taking your prescribed prenatal vitamins to support your baby’s development, especially in these early stages.

Your Body in 21 Weeks

At this point, your body will start to look very pregnant. You may even already know the gender of your baby by now. In most cases, doctors set ultrasound appointments for gender determination around weeks 18 to 21.

Besides that, here are some other changes you may experience this week:

Stretch Marks

As your belly expands to accommodate your growing baby, you may notice stretch marks appearing on your abdomen, breasts, and hips. This can appear to be pink, red, purple, reddish-brown, or dark brown streaks.

These are a natural part of pregnancy, and while they cannot be entirely prevented, keeping your skin moisturized can help reduce their severity.


At week 21, the reality of your pregnancy will truly sink in. Your belly is big, and you feel your baby kicking. 

With all the changes happening in your body and the anticipation of becoming a mother, it’s entirely normal to feel anxious. For many expectant mothers, anxiety is even coupled with shortness of breath.

When this happens, talk to your partner, friends, loved ones, or a healthcare professional. It can get overwhelming but remember you are not alone in this journey!

Symptoms You May Experience During the 21-Week Mark

Symptoms You May Experience During the 21-Week Mark

As you enter week 21 of your pregnancy, you might start to feel new symptoms you did not experience in week 20.

Let’s explore the possible symptoms this week and how to manage them:

1. Fetal Movement

I remember exactly how week 21 felt because it was the first time I got to experience more noticeable movements from the baby in my belly.

You can truly appreciate the miracle of life as you feel your baby twisting, turning, and kicking inside your womb. These may start gently and gradually develop into more defined kicks and rolls.

2. Increased Appetite 

Naturally, as your baby needs more nutrients to support their growth, you will feel the need to eat more. As this occurs, make sure you are still making healthy choices for your diet

Always carry with you healthy snacks like nuts, raisins, soda crackers, granola bars, and trail mix. These are super convenient, especially when you need something to fill you up when you’re on the go.

3. Bloating and Gas

Another common pregnancy symptom you will likely experience throughout your journey is bloating and increased gas. 

The growing pressures from your uterus pressing on your rectum, plus the hormonal changes, are to blame.

I found that eating smaller, more frequent meals and avoiding gas-inducing foods can help alleviate the discomfort. 

Drinking plenty of water and eating fiber-rich foods helps avoid constipation that makes you extra gassy too.

I also like to wear good maternity underwear to make me comfortable with the uneasiness of bloating.

4. Back Pain

As you progress through your pregnancy, your baby grows, and your center of gravity shifts. The hormone relaxin, released during pregnancy, also causes ligaments and joints to loosen up. This means you will feel the extra strain on your back. 

In my experience, being extra mindful about my posture greatly helps me manage the ache. Using supportive pillows for your much-needed good night’s rest too.

If you feel like splurging, go for a prenatal massage. You deserve it!

5. Bleeding Gums

Have you noticed any blood when you brush your teeth lately? That’s probably from your bleeding gums. 

Pregnancy hormones can cause your gums to become more sensitive and prone to bleeding.

I suggest laying off the sweets in the meantime as this can increase bacteria in the mouth and further irritate your gums. Maintain good oral hygiene and visit your dentist regularly too.

6. Fast-Growing Nails

Some women notice that their nails grow faster and stronger during pregnancy. Pregnancy hormones are the likely cause once again.

You’ll need to do more nail trimming this week and in the coming weeks to come.

Tips to Help You Manage Week 21

Tips to Help You Manage Week 21

Pregnancy is a wonderful journey, but it’s not always the easiest. Here are some of my tried and tested tips to help you manage this week:

1. Unstuff Your Nose

Have you been experiencing a stuffy nose more than usual lately? It might not always be from seasonal allergies. Hormonal changes can lead to nasal congestion too. 

To clear your nasal passages, close one nostril with one thumb and gently blow. Do the same with the other nostril.

If the stuffiness is persistent, consult with your healthcare professional for a safe saline nasal spray, decongestant, or antihistamine you can use.

2. Elevate Your Feet

It’s normal to experience swollen feet and ankles. These days, you’ll likely find it hard to put your shoes on more than usual. 

That’s because your body is retaining more blood and fluid to support your growing baby.

Reduce swelling in your feet and ankles by elevating them whenever possible.

3. Don’t Rush Hitting Your Target Weight

Every woman’s body is different, and weight gain during pregnancy varies. Ideally, your target weight increase at week 21 should be between 10 to 16 pounds.  

But don’t worry too much if you don’t hit it immediately. Focus on nourishing your body and trust that it will gain the appropriate weight to support a healthy pregnancy.

4. Walk for Around 30 Minutes a Day

Light exercise during pregnancy and even in your first few weeks postpartum will help you maintain your overall well-being.

Even just a half-hour of walking will do just the trick! Don’t forget to drink a lot of water to prevent dehydration when exercising too.

5. Avoid Lasers

Raging hormones during pregnancy can cause your legs, armpits, bikini line, and upper lip to be hairier than usual. 

You might be tempted to have them removed as soon as possible. But I advise you to think twice and consult with your doctor when using hair removal lasers, electrolysis, and depilatories. 

Other skin treatments, especially for skin lightening, may be harmful too. 

The effects of these treatments are not well-studied. To be safe, avoid any procedures while you are pregnant. For now, stick to pregnancy-safe moisturizers, toners, and other skincare products.

6. Organize Your Calendar

As your due date approaches, life can get hectic, and brain fog can be rampant. 

Make to-do lists, leave notes for yourself, and don’t be afraid to ask for help on tasks around the house. Stay organized with appointments and baby preparations to reduce any stress.

7. Limit Empty Calories

Sugary treats, junk food, and other processed food need to go out the window! 

Opt for nutrient-dense foods to ensure you and your baby receive enough of the essential vitamins and minerals needed for full development.


Week 21 of your pregnancy marks an important milestone in your journey to motherhood. Your baby is growing and developing rapidly while your body experiences various changes to support this new life.

I encourage you to embrace the changes and take care of yourself physically and emotionally. 

Reach out for support when needed, and cherish the special moments of feeling your baby move inside you. 

Wishing you a happy pregnancy!

Nayna Llenos
Nayna Llenos

Hi, I’m Nayna!
I’ve always wanted to be a mother, and I’m lucky and blessed to have two wonderful children to care for and love.
Despite this blessing, there are times wherein I do wonder if I truly am the mother my children need. Am I giving them the right food, care, and discipline to them?
But that is the beauty of parenting — you grow along with your children as they flourish to be their wonderful selves!
I wish to share my experiences with motherhood and how these tips can help you in your parenting journey.
I hope my advices and experiences will prove useful to you and that you have a smooth and wonderful journey as a mother!