Pregnancy Week By Week

21 Weeks Pregnant

Pressure’s on! Have you found the perfect baby name yet? It seems like parents-to-be either come up with baby’s name quickly and easily, or agonize over it all the way up until the birth. If you haven’t picked that perfect name yet, check out The Bump’s extensive lists of baby names of all sorts; cool names, beautiful names, hipster names and much more. Whatever name you choose, you’ll probably think it’s even more perfect once you get to know (and fall in love with) your future little bundle of joy. At 21 weeks pregnant, you’re not just choosing a name, you’re hard at work getting your home ready too. Of course, things like baby bouncers and changing table pads can be tough to choose, but try not to stress about it at week 21 of pregnancy. Trust us, baby won’t care if you pick out a pack ‘n play that clashes with the area rug!

How Big Is Baby at 21 Weeks?

At 21 weeks pregnant, baby is as big as a head of endive. At 10.5 inches and about 12.7 ounces, baby is big enough now that you've probably been feeling their fetal movements more and more lately.

21 Weeks Pregnant Is How Many Months?

Twenty-one weeks pregnant is five months pregnant, although doctors track pregnancy by week, not month. Since pregnancy is 40 weeks long, you’re now a majority of the way through your pregnancy!

21 Weeks Pregnant Symptoms

Common 21 weeks pregnant symptoms are kind of like a sneak preview of the third trimester. Here’s what you might be feeling at week 21 of pregnancy:

  • Heartburn and/or indigestion. Avoid spicy and greasy foods and other triggers. If the source of your discomfort is a mystery, keeping a food diary could help you figure it out.
  • Braxton Hicks contractions. Your uterus might occasionally feel tight as it practices for labor. This is totally normal as long as the contractions go away when you switch positions. Let your doctor know about any pain or contractions that don’t stop.
  • Leaky boobs. Your milk ducts will be fully developed by the end of this trimester—just in case of an early arrival.
  • Dry, itchy skin. Your skin is stretching over your growing bump, making it more irritated by the day. Lather up with a pregnancy-safe body oil or lotion to help your skin stay moisturized and hopefully less itchy. Also, if you develop a rash, let your doctor know right away, since that could be a sign of an annoying pregnancy condition called PUPPP.
  • Stretch marks. Your skin gets pulled thinner as baby grows, causing tiny tears beneath the surface of your skin. Stretch marks are more common for some women simply because of family history or because of sudden weight gain. They are also more common in women who are 21 weeks pregnant with twins. There’s no way to truly get rid of stretch marks, but they should fade significantly after birth.

21 Weeks Pregnant Belly

This week, you may look in the mirror and wonder, “Where did I go?!” By the time you reach 21 weeks pregnant, you may have gained around 13 to 14 pounds, and around 21 pounds if you’re 21 weeks pregnant with twins.

Your newfound curves might have you feeling super sexy and confident—after all, you’re the center of attention wherever you go! But the extra weight also might have you feeling, well, fat. (You’re not—you’re pregnant!) Remind yourself, you’re supposed to be gaining this weight! It’s good for you and for baby.

In fact, all the weight you gain during pregnancy isn’t just padding for baby—it all serves a really important purpose. Here’s a logical way to think of it: Of the approximately 30 pounds you’ll gain throughout your pregnancy, there’s a whole lot more than fat. Here’s what makes up that weight:

  • An average full-term baby = 7.5 pounds
  • Placenta = 1.5 pounds
  • Uterus = 2 pounds
  • Amniotic fluid = 2 pounds
  • Maternal stores of fat, protein, and other nutrients (needed for breastfeeding!) = 7 pounds
  • Breast tissue (also for breastfeeding, of course) = 2 pounds
  • Increased fluid volume = 4 pounds
  • Increased blood volume = 4 pounds

See? All those pounds are doing a lot of good, keeping baby alive and healthy—and storing up good stuff to nourish them after birth. Any time you’re feeling a little meh about your body, think of all the amazing things it’s doing!

Now, at 21 weeks, fetal movement is noticeable—and baby has reflexes too! If you gently press your palm on your belly, you might feel a little push back. So cool!

21 Weeks Pregnant Ultrasound

Wondering what’s going on with your 21-week fetus? As baby's digestive system preps for the outside world, they’re manufacturing meconium, the tarry black substance you'll find in the first dirty diaper.

Bet you hadn’t even thought about future grandchildren yet, but the reproductive system is developing too. If it's a girl, she's already got a lifetime supply of eggs in her womb—about six million of them! Having a boy? His testes are still located in his abdomen but will drop in the coming weeks once the scrotum finishes developing.

You’ll get a glimpse of that cute little 21-week fetus if you have your mid-pregnancy ultrasound this week. This 21 weeks ultrasound will amaze you! Not only will you get to see baby on the screen, you’ll also get to see some awesome details like the brain hemispheres and chambers of the heart. Let your technician know whether or not you want to know baby’s sex.

Finding out whether it’s a boy or a girl is a pretty exciting moment! But you can also save it for later if you want. Some parents-to-be wait until baby is born to know the sex. Or you could ask the technician to write it down and put it in an envelope so you can take it home. Then, you could plan a gender reveal party, where you can find out the surprise while surrounded by your family and friends. Fun!

Ask for lots of printouts of the pictures, because if you have an uncomplicated pregnancy, this may be the last medical ultrasound you’ll get during pregnancy. Now go show off those photos of your cutie! And keep brainstorming those names!

Pregnancy Checklist at 21 Weeks Pregnant

Reminders for the week:

Medical content was reviewed February 2020 by Patricia Pollio, MD, a New York-based ob-gyn and director of the department of obstetrics & gynecology at Good Samaritan Hospital in Suffern, New York.

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