Pregnancy week 21

Week 21 of Your Pregnancy

Now that you are officially in the second half of your pregnancy, it’s time to learn about Braxton Hicks. Yes, these “practice contractions” can occur during your second trimester. But there’s more to week 21, too. Here, several experts discuss what to expect during this period.

It's week 21 of your pregnancy, and by now, you probably know the sex of the fetus—unless, of course, you want to be surprised. You're probably far removed from the nausea woes, and fatigue has likely waned, but during this week (and subsequent weeks) you may experience some new and unexpected symptoms. Read on to learn all about week 21 of your pregnancy.

Pregnancy Week 21 Quick Facts

  • At 21 weeks, you're five months pregnant
  • You have 19 weeks until your due date
  • You’re in your second trimester

Your Unborn Baby's Size At 21 Weeks

At this stage, your unborn baby measures about 10.51 inches long and weighs around 12.70 ounces. This means they're about the size of a carrot!

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Pregnancy Symptoms Week 21

While your symptoms may be similar to week 20 of your pregnancy, there are a few new ones to discuss during week 21, including:

While breast tenderness is usually an early sign of pregnancy, in week 21, this discomfort may return, as your breasts begin to swell and enlarge. "As your breasts grow, your veins under the skin will become more visible. They may also be more tender," says Monte Swarup, M.D., FACOG, a board-certified OB-GYN in Chandler, Arizona.

Lower back pain is also no joke. After carrying my twins, I have recurring pain if I twist the wrong way or lift too much. For week 21, doula Kortney Lapeyrolerie, says, "Sleeping on a wedge is very helpful. Using [ice or] a heating pad for up to 20 minutes can also relieve discomfort." Still in pain? Try placing a pillow between your knees when sleeping on your side to help align your spine.

Oh, and don't be surprised if you begin to have slight contractions during week 21. These are referred to as Braxton Hicks. Your abdomen can tighten after certain activities, which is common in the second trimester. As your body grows and accommodates your pregnancy, sometimes these “contractions” are its physical response. (I experienced them often and had to accept that they were a part of my pregnancy. They weren't painful, just noticeable.) However, to ease your mind, let your OB-GYN, midwife, or health care provider know what you're experiencing so they can provide insight.

Developmental Milestones

At 21 weeks, your unborn baby may start to react to certain foods. Yes, the meals you ingest could get a rise from them—for good or ill.

"Your baby will start to respond to foods as they swallow a small amount of amniotic fluid, which helps them practice swallowing. The amniotic fluid changes taste depending on what the expectant parent eats each day," Dr. Swarup says. But most of their nourishment comes from the placenta.

In addition to responding to your diet, your unborn baby is probably responding to your touch now, which is a pretty sweet developmental time because you can begin interacting with your unborn baby as they move. "At 21 weeks, your baby has more control over their limbs, so you will feel lots of kicking and stretching," Dr. Swarup explains.

Prenatal Tests and Doctor's Visits

By now, you've probably had an anatomy scan to see how the fetus is developing. (If not, you’re likely having it this week.) However, if the former is the case, this is likely an “off week” for you, meaning no doctor’s appointments or prenatal tests. 

That said, you may still be awaiting the results of your amniocentesis, if you opted to have one. If the wait is weighing on you, try to keep up with your daily activities and stay positive. You can also share your thoughts with your spouse or partner, if you have one, or a close friend. If you have support, don't carry it alone.

"Don't hesitate to talk with a health care provider for your stress and mental well-being," Dr. Swarup suggests.

Common Questions At This Stage Of Pregnancy

Why isn't my baby active when I am?

Fetal movement depends on many factors. Dr. Swarup explains that, at 21 weeks, you can and should expect to feel your unborn baby move multiple times a day. But that doesn’t mean they’ll move with you. "It is common to feel movement when you are resting and calm because small movements are not noticed as much when the expectant parent is busy," says Dr. Swarup. Movement consistency is different for every pregnant person too, but you should always contact your provider if you have concerns.

Am I gaining too much weight?

Pregnancy is a huge mix of hormonal changes, physical changes, mood shifts, and more. All of which can affect your weight. And while some doctors believe a set amount of weight is ideal, every person and pregnancy is different. 

If you have concerns, the Center For Disease Control and Prevention (CDC) offers a standard guide for single pregnancies and those pregnant with multiples. Keep in mind, however, that this can vary based on certain factors, like height and age.

Things You Might Consider This Week

Your body is doing a lot of work. A lot. And while your third trimester is still seven weeks away, it will be here before you know it. Soon, baby will begin to take up more space. This may limit your mobility for things like bending, tying your shoes, or even reaching around your belly to lift a laundry basket. Start creating habits around your comfort and mental health now. Dr. Swarup suggests warm baths, meditation, breathing exercises, and plenty of sleep. And get in the habit of asking for help. (No, you may not need it yet, but it doesn't hurt to ask.)

You may also want to start thinking about your birth plan this week, if you haven’t already. A birth plan is a written outline of what you would like to happen during labor and delivery. It lets your doctor, midwife, nurses, and other members of your care team know your wishes.

Oh, and week 21 is also a great time to invest in a yoga ball. Sitting on it can relieve hip and lower back pain and open your pelvis area. "Engaging a yoga ball for up to 20 minutes is a great way to prepare for the positions that you will have to be in during birth," says Lapeyrolerie.

Support You May Need This Week

Now is a great time to check area hospitals and care facilities for childbirth classes. These classes offer information and techniques which include the best positions for childbirth. They will teach your partner—if you have one—how they can support you through the labor and delivery process, and childbirth classes can help you decide which type of birth is right for you (epidural, natural, home birth, etc.).

Head over to week 22 of pregnancy

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