Week 21 of Your Pregnancy

Verywell / Bailey Mariner 

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At 21 weeks pregnant, you are in the second half of your pregnancy. As your baby grows, you may be able to feel more movement. You may also be feeling the effects of extra fluid in your body.

21 Weeks Pregnant Is How Many Months? 5 months and 1 week

Which Trimester? Second trimester

How Many Weeks to Go? 19 weeks

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Your Baby's Development at 21 Weeks

At 21 weeks, baby measures a little over 7 inches (18.1 centimeters) from the top of their head to the bottom of their buttocks (crown-rump length). Baby's height is approximately 10 inches (25.9 centimeters) from the top of the head to the heel (crown-heel length). The baby weighs around 14 ounces (398 grams).

At 21 weeks pregnant, your baby is about the length of a potty
Verywell / Bailey Mariner  


The placenta is still delivering the majority of the baby's nutrients. But, the baby's digestive system is developing and maturing to take over after birth.

  • The pancreas is beginning to make enzymes that break down food for digestion.
  • The small intestine is growing longer and absorbing nutrients from the amniotic fluid that the baby swallows.

Red Blood Cells

Up until this point, your baby's liver made most of the red blood cells. But now, their bone marrow is becoming a major contributor. By 24 weeks, the bone marrow will take over as the primary producer of baby's red blood cells.


Your baby's eyelids, which closed and sealed together around week 11, are now beginning to separate.

Explore a few of your baby's week 21 milestones in this interactive experience.

Stay Calm Mom: Episode 3

Watch all episodes of our Stay Calm Mom video series and follow along as our host Tiffany Small talks to a diverse group of parents and top doctors to get real answers to the biggest pregnancy questions.


How Will Pregnancy Change My Body?

Your Common Symptoms This Week

This week, you may continue to have some of the typical discomforts of the second trimester such as:

Pregnancy also brings about changes in your circulation. So, you may begin to notice swelling in your feet and ankles or varicose veins.


Your belly may not be the only thing getting bigger. Your feet and ankles might be expanding, too. Up to 80% of pregnant people experience some degree of swelling or edema in the legs. Swollen feet and ankles are often worse:

  • At the end of the day
  • After standing or sitting for a long time
  • When the weather is hot

Varicose Veins

Varicose veins are swollen, twisted veins that look purple or blue and bulge from the skin. During pregnancy, vein issues are more common because of the added weight of the growing uterus, hormone changes, and extra fluid in the body.

Varicose veins can cause pain, aching, leg cramps, or a feeling of heaviness in your legs. They typically appear on the legs, but they can also show up on the vulva or the rectum. Swollen veins in your rectum or anus are better known as hemorrhoids.

Self-Care Tips

Continue to care for your physical and mental health every week by eating well, getting some exercise, maintaining your social relationships, spending time with your partner, and participating in safe activities that you enjoy. This week, you may also want to prevent or relieve symptoms related to additional fluid in your body.

Dealing With Swelling

You can’t do anything about the extra fluid and hormones that contribute to swelling in your legs and feet, but you can try to lessen your discomfort.

  • Drink up. While it seems counterintuitive, drinking more fluids can flush out the waste that may contribute to swelling. Opt for water as your beverage of choice as much as possible.
  • Swap your socks. Trade any elastic-top socks for support hose.
  • Change positions. Gravity pulls fluid down, so sit or lie down with your feet up as much as possible. When standing for a long stretch, use a stool to prop up one foot.
  • Move around. Get a little exercise or take short breaks throughout the day to walk around.
  • Go in the water. If your doctor says you can swim or take a bath, get in the water. The pressure of the water outside your body may help to push the excess fluid in your feet back into your veins to help reduce the swelling. If you can't swim or bathe, soak your feet in a tub of water.
  • Change your shoes. You may need to go up a size or switch to a different shoe style to find comfort while dealing with swollen feet.

What Experts Say

“Swelling may also be reduced by eating foods that are high in potassium, such as bananas, lima beans, sweet potatoes, bok choy, and spinach.”

Dana Angelo White, MS, RD

While swelling of the feet and ankles is usually normal, other types of swelling could be a sign of an issue. Call your doctor if you swell up suddenly, especially with rapid weight gain, or if you notice swelling in your hands or face.

Dealing With Varicose Veins

Most of the time, doctors do not need to treat swelling and varicose veins in pregnancy. They're typically expected to get better once the baby is born. But you can try to prevent or relieve swollen veins by:

Your Week 21 Checklist

Advice for Partners

Pregnancy can be a happy time, but it can also be a time of worry or stress for both of you. Pregnant couples often worry about genetic testing and the health of the baby. On top of that, financial uncertainty, relationship concerns, and the reality of becoming a parent might also weigh on your mind.

Studies show that stress can affect pregnancy and the baby. It can also affect your physical and mental health. You can try to keep your family healthy by working on ways to help you and partner reduce stress, including:

  • Get some regular exercise.
  • Try relaxation techniques like deep breathing exercises, progressive muscle relaxation, and meditation.
  • Learn to recognize the signs of stress.
  • Go to bed early.
  • Let some of the chores go undone, and do something fun instead.
  • Take a day off of work to spend together, if you can.
  • Talk to each other about the things that are causing worry.
  • Speak to a health care or mental health professional if you need help dealing with stress.

Stress is a normal part of everyday life, and it's not always a bad thing. Stress can motivate you and push you to make positive changes in your life (or just get the nursery ready). But, if it becomes overwhelming, it's important to take steps to deal with it.

Upcoming Doctor’s Visits

Special Considerations

Bleeding during pregnancy can be scary. While it doesn't always mean there's a serious problem, it's important to have it evaluated right away, just in case.

Vaginal Bleeding

Many things can cause vaginal bleeding during pregnancy. Some issues are minor and don't pose any threat to your pregnancy or your baby. For example, you may experience light bleeding:

  • After sex
  • After a pelvic exam at your doctor's office
  • If your cervix is irritated or has a growth (polyp) on it

However, bleeding can sometimes be a sign of a complication such as:

While some causes of bleeding are minor, you really won't know for sure until you have it checked out. So, treat any bleeding as though it is an emergency until you find out otherwise. Contact your doctor right away or go to the emergency room for an examination. Learning the cause can give you peace of mind, and it also allows your doctors to treat you for any potential complications as early as possible.

A Word From Verywell

During the first half of pregnancy, you may have had a positive test, heard a heartbeat, and seen an image of your baby on an ultrasound screen. Now, in the second half of pregnancy, seeing your belly grow and feeling the baby move tends to make it feel more real.

Next week, your baby may be exploring the sense of touch, and you might start to feel an occasional tightening sensation in your uterus.

17 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Holly Pevzner
Holly Pevzner is an award-winning writer who specializes in health, nutrition, parenting, and family travel.