21 Weeks Pregnant: Week-by-Week Guide
Mom Development 21 Weeks

21 Weeks Pregnant: Week-by-Week Guide

Congratulations! You’re 21 weeks pregnant and just over the halfway mark. At this stage of your journey, new developments are beginning to unfold. Check out this week-by-week guide to find out what’s in store for your body and your baby at 21 weeks.

What trimester is 21 weeks? Second trimester
How many weeks of pregnancy are left? 19 weeks
How many months is 21 weeks pregnant? You are five months pregnant.

With week 20 of your pregnancy complete, you’re on week 22! Enjoy it, as week 22 is on the horizon!
One of the most magical things about pregnancy is how much changes with your little one and you over the span of just
seven days! Here are some tips and tricks to keep on top of all that’s happening.

Your baby at 21 weeks pregnant:

What's happening in there

  • Your baby is the size of a large banana.

  • You’re in the middle of the second trimester and are almost six months pregnant.

  • The countdown continues: You’ve got 19 weeks to go!

What happens during the 21st week of pregnancy?

  • Make the connection: With your baby’s cognitive development humming along, those billions of neurons are connecting to muscle, allowing your baby to become more active. You may feel those effects. Most future mamas feel babies start to move from 16 to 24 weeks, but if you’re a first-time mom, you might not have felt movements until now.
  • Strong bones: Cartilage throughout your little one’s body is turning to bone, and those bones are continuing to grow and get stronger each day.

  • A blood cell factory: Now that the bones are formed, they start to produce red blood cells in the bone marrow, ready to transport oxygen around the body for the second half of the pregnancy.

  • Getting ready to feed: While most of the nourishment comes through the placenta, your baby can now swallow and digest amniotic fluid and pass waste to the large bowel.

What should I be feeling at 21 weeks pregnant?

  • You'll feel beautifully curvaceous on some days and feel bloated and over it on others. Ride those waves; you're halfway there.
  • Your little baby will likely be pushing and kicking, ranging from gentle pokes with their hand to giving you some enthusiastic kicks—perhaps soccer stardom is in their future!

  • If you haven’t already had it, you’ll be due for your ultrasound, where you will get a good look at your little creation and be able to find out the sex of the baby!

How big is a baby at 21 weeks pregnant?

21 Weeks Pregnant
Baby Weight 11 ounces
Baby Length 7 inches from crown to rump
Baby Size Comparable to a long banana

What does a 21 week fetus look like?

Your little wonder is a banana-sized baby! Fingers and toes, along with fingerprints, are developed, as are the face, spine, and heart. You may have an ultrasound this week and get a close view of your belly’s tiny occupant. If you choose, this may be the time for the exciting gender reveal.

Week 21 pregnancy symptoms

During week 21 of pregnancy, your body is changing quickly. As your baby grows, you will too, and there are certain pregnancy symptoms you may experience at this time.

7 common week 21 pregnancy symptoms

  1. Braxton Hicks contractions may start to happen—it’s your uterus tightening and loosening as it gets prepped for labor.

  2. Now your breasts are ready for feeding. As a result, you may get leaky nipples.

  3. Your hair and nails will probably be growing faster. Enjoy those luscious locks!

  4. The extra weight you’re carrying right now can cause backaches and pains, so keep off your feet and elevate your legs when you’re sore. Trying some pregnancy-safe workouts can also help alleviate back pain.

  5. You should be feeling lots of fluttering fetal movement as your little one kicks, wiggles, and changes position within the womb.
  6. As your belly rapidly expands, you may notice stretch marks and itchiness. Moisturizer and a doctor-approved anti-itch cream may help. 
  7. A slower digestive system and pressure on your abdominal cavity from your growing uterus may leave you feeling extra gassy. Exercise, avoid fatty foods, eat slowly, and stay hydrated to help reduce excessive gas and bloating.

4 tips for week 21 for a healthy and safe pregnancy 

Being 21 weeks pregnant is an important time for you and your baby. Here are some tips on how to adjust to this new stage to keep you and your baby safe.

  • Get in those greens: What you eat when you’re pregnant can give your baby a taste for good, healthful foods like fruits and vegetables, as the flavors wind up in the amniotic fluid your little one is swallowing. Your baby may develop a fondness for those foods after they are born.

  • Opt for a balanced plate: In a recent study, women who ate well during pregnancy (like consuming plenty of vegetables, fruits, whole grains, and water) had a much lower risk of preterm delivery. Trying out some healthy recipes can help provide variety for you and your baby.

  • Plan your leave: The government entitles most new parents to 12 weeks of unpaid leave. If you haven’t already, find out your employer's policies on paid leave or disability.

  • Practice seat belt safety: Wear the three-point seat belt so the lap belt is under your belly (not across it) and the shoulder strap is between your breasts.

Week 21 pregnancy checklist

Knowing what to do week-by-week can help you feel prepared and alleviate stress. Add these items to your to-do list this week. You’ve got this, mama!

To-Do Complete
Spend some time planning what you’ll need for the nursery.
Haven’t decided on a name? Maybe it’s time to cull some of them off that ever-growing shortlist.
Take some time out just to be a couple, like a “babymoon,” date night, or even just a picnic.

Learn more about your pregnancy, including pregnancy planning and pregnancy nutrition, to feel prepared to continue this magical adventure. You’re armed with the facts and know what to do, so now you can take time to connect with the little one growing inside you.

With week 20 in the rearview mirror and week 21 of your pregnancy going strong, look to the future and what's coming up in week 22!

Join Enfamil Family Beginnings

At 21 weeks pregnant, you’re more than halfway there. Start preparing for your new arrival with Enfamil Family Beginnings. It’s the perfect resource for new and expecting moms. Save on Enfamil products, track your bump and baby’s growth, and get helpful articles each week relevant to your journey. Join now for up to $400 in free gifts.