Want to know what happens next week? (Have similar information sent straight to your inbox every week)
Enter Due Date:
Enter E-mail:
Type the code:
Track Your Baby's Development Week By Week
Track Your Baby's Development Week By Week
..where little means a lot

Note: The length, weight and size mentioned below are only a guideline, as these vary from baby to baby and from one pregnancy to another.

What is going on with your baby during week 21?

  • From crown to rump your baby measures at 7 inches, and weighs about 10½oz. Fetus is now the length of a spoon.
  • Growth rate has slowed down - weight gain for baby is more sure and steady now.
  • All the body systems will mature at a gradual pace.
  • Baby swallows amniotic fluid to prepare the digestive system for functioning after birth; any unabsorbed material in the fluid becomes the meconium in baby's intestinal tract.
  • Baby regularly drinks amniotic fluid for hydration and nutrition, urinates in the fluid and breathes in and out. The fluid pool is replenished with fresh stock every 3 hours.
  • Baby's eyebrows and eyelids are fully formed; although the eyelids are sealed, the eyes are active.
  • Taste buts are beginning to form on her tongue.
  • Bone marrow is starting to make blood cells.

Week 21 Fetus

Changes in you at this stage Week 21

  • Time has come to say goodbye to your waistline.
  • Blood vessels in your breasts are continuing to be more visible.
  • At 21 weeks the hormones progesterone and estrogen will be at par and by 24th week the estrogen level will be slightly higher.
  • Your blood pressure will continue to stay lower than normal this week.
  • If you are getting enough iron, production of red blood cells should be catching up to production of plasma. If not, the risk of developing iron deficiency anemia will rise.
  • Nasal congestion, nosebleeds and bleeding gums are commonplace. These are due to the continued increased blood flow to the nasal passages and gums.
  • You may gain 1½ pounds this week and only half a pound the next, but this is no cause for concern. Weight gain should be steady without drastic changes.

Good to Know in Week 21

In General

  • Your BP reaches its lowest levels during the second trimester. If you get lightheaded, stand still and let it pass. If it doesn't pass sit down and put your head between your knees.
  • Braxton Hicks contractions start around now. Each contraction can last for a few minutes to several minutes.

Smooth muscles

  • Your body has three types of muscles: skeletal, cardiac and smooth. Muscle changes impacts your pregnancy causing everything from constipation to vision changes.
  • Pregnancy has the most effect on smooth muscles which are found in your uterus, stomach bowels, in the iris of your eye and in hair follicles. This kind of muscle is not under your voluntary control.
  • Some smooth muscles relax their functions during pregnancy like the ones in your bowels. The smooth muscles in your arteries also relax causing your vessels to widen and in turn lower your blood pressure and more blood then flows into the placenta.
  • Smooth muscles also regulate contractions during labor; first the falsies in the form of Braxton Hicks contractions and eventually the real ones to help in the birth of your baby.

Wholesome Advice in Week 21

  • If this is your first pregnancy and you are not sure of the difference between real contractions and Braxton Hicks, do not ignore contractions that intensify and increase in frequency. This can be a sign of premature labor.
  • Start educating and preparing yourself early on either medication or relaxation techniques to help you deal with labor.
  • If local water is an issue when you are traveling, avoid ice cubes in restaurants. Avoid tap water. Choose canned or bottled drinks; make sure the bottles you buy are sealed. If still in doubt opt for sparkling water with low sodium content. You can also treat water with purifying tablets or by boiling and filtering it.

Your actions can impact your baby's growth at this stage


  • Fiber is not digested by your body - it passes through and helps to alleviate constipation. Both soluble (oat bran, beans, peas and psyllium husk) insoluble fibers (whole wheat products) are required. Soluble fibers absorb liquid and form a gel while insoluble doesn't. Most fruits and vegetables contain both.


  • This is a safe fiber supplement - it is not a laxative. You can buy psyllium without additives, dyes and sugar versions from health food stores. Start slowly once a day for a few days. Work your way up to twice a day if you see no improvement.


Since you are more prone to falls now that there are changes in your center of gravity, learning to reduce the likelihood with certain precautions is helpful. During your normal daily life:

  • avoid high heels
  • walk on pathways whenever you can
  • avoid uneven surfaces or stony paths or stones
  • wear appropriate footwear whenever you work out If you do fall do not panic. Check yourself out thoroughly before standing back up. Mostly remember that your baby is well cushioned by the amniotic bag. However in the event of any abdominal pain, bleeding, contractions or changes in baby's movements, inform your doctor immediately.
Free baby Sample

Common Concerns in in Week 21

Should contact lenses be a concern during pregnancy?

  • Water retention can change the shape of your eyeball and therefore the fit of the lenses. It is worth getting your eyesight and the fit of your lenses checked out. If your eyesight is changing you might want to consider disposable lenses so that the prescription can be changed more swiftly and economically throughout your pregnancy. If you suffer from dry eyes you may want to limit the time you wear your lenses and use your glasses in between. If you have blurred vision and flashing lights check this out with your doctor before seeing your optician as the cause may be something more serious such as gestational diabetes.

Will flying harm my baby?

  • There is no evidence suggesting this to be a fact. Heavy exposure to atmospheric radiation during flying has been linked to an increased risk of miscarriage and Down’ syndrome and for this reason it is not advisable to fly during the first trimester. However the risk to females who only fly occasionally is negligible.

Are airport screening machines safe?

  • They use low-level metal detector so they are safe. The same holds true for wands that are passed over passengers. Many people think these machines take x-rays - they don't. Airport x-ray machines are used only on luggage.

Weekly Nutrition advice in Week 21

  • Some women experience cravings during pregnancy. Food cravings have long been considered a nonspecific sign of pregnancy.
  • Cravings can be good and bad. If the food you crave is nutritious and healthful, eat it in moderation. If you crave for foods high in fat and sugar or loaded with empty calories, watch out! Indulge a little but don't let yourself go.
  • Try substituting with something more nourishing such as a fruit or low-cal flavored yoghurt instead of giving in to your whim.
  • Hormonal and emotional changes are responsible for cravings.
  • On the reverse side of the coin is food aversion. Some foods that you used to enjoy before becoming pregnant now make you sick in the stomach. This is common.
  • Again, hormones are to be blamed; hormones affect the gastrointestinal tract which can affect your reaction to some foods.

What foods do pregnant women crave? Recent research indicates the top three cravings as below:

Chocolate 33%

Sweets of some sort 20%

Citrus fruits and juices 19%

Disclaimer: Information contained on this Web site is intended solely to make available general summarized information to the public. It should not be substituted for medical advice. It is your responsibility to consult with your pediatrician and/or health care provider before acting on any advice on this web site. While OEM endeavors to provide up-to-date and accurate information, it is not liable for any advice whatsoever rendered nor is it liable for the completeness or timeliness of any information on this site.

All Rights Reserved. © 2022 Welcome Baby Home-2013 Privacy Policy | Terms of Use