Pregnancy Week 21
Pregnancy Week 21

By this week, your baby weighs approximately as much as a medium-sized carrot!

As you enter the second half of your pregnancy, it’s time to familiarize yourself with Braxton Hicks contractions, also known as “practice contractions,” which can occur during the second trimester. But that’s not all there is to week 21!

By now, you may already know the sex of your baby, unless you’re waiting to be surprised. Nausea and fatigue may have subsided, but you might experience new and unexpected symptoms during this week and beyond. To learn more about what to expect during week 21 of your pregnancy, read on as several experts share valuable insights.

Pregnancy Week 21 Quick Facts

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

Your Unborn Baby’s Size at 21 Weeks

Think about your baby size?

At this stage, your unborn baby measures about 26.7 centimeters long and weighs approximately 360 grams. This is equivalent to around 0.28 pounds or 12.7 ounces, which is about the weight of a medium-sized carrot!

Pregnancy Symptoms Week 21

During the 21st week of pregnancy, you may notice some new symptoms in addition to those experienced during the 20th week. 

The symptoms that may arise during the 21st week of pregnancy include varicose veins, acne or oily skin, round ligament pain, low back pain, and Braxton Hicks contractions. 

Again Feel Breast Tenderness?

Although breast tenderness is commonly experienced early in pregnancy, it may return during week 21 due to the ongoing growth and expansion of your breasts. As your breasts enlarge, the veins beneath your skin may become more visible and tender.

Low back pain can also be a challenging symptom to deal with.

If you have carried twins or have a history of recurring pain, twisting your body in the wrong way or lifting heavy objects can exacerbate the discomfort. 

Sleep Discomfort? 

During week 21, using a wedge to elevate your sleeping position or applying a heating pad for up to 20 minutes can provide relief. Additionally, placing a pillow between your knees when sleeping on your side can help align your spine and alleviate pain.

Can you feel Contractions?  

In the 21st week of pregnancy, you may experience mild contractions, known as Braxton Hicks. These contractions can cause your abdomen to tighten after certain activities, which is typical during the second trimester. As your body adjusts to your growing pregnancy, these contractions can be a natural response. They are usually not painful, they may be noticeable. 

Prenatal Tests and Doctor’s Appointments

  • Typically, your next regular prenatal check-up will occur at approximately 24 weeks into your pregnancy. 
  • Additionally, between weeks 24 and 28, you should anticipate a screening test for gestational diabetes.

– Risk in the 21th week of pregnancy

Experiencing bleeding during pregnancy can be alarming. 

Although it may not always indicate a serious issue, it’s crucial to have it assessed promptly as a precautionary measure.

Vaginal Bleeding

Various factors can lead to vaginal bleeding during pregnancy. Some causes are minor and pose no risk to your pregnancy or your baby, such as :

  • light bleeding after sex 
  • Pelvic exam at hospital for check-up
  • Infection 
  • low-lying placenta
  • premature opening of the cervix
  • early labor
  • separation of the placenta from the uterus.

While certain causes of bleeding may be harmless, you can’t be certain until you’ve had it evaluated. Therefore, it’s essential to consider any bleeding a medical emergency until proven otherwise. Get in touch with your healthcare provider immediately or visit the emergency department for an examination. Knowing the cause of the bleeding can provide peace of mind, and it allows your healthcare team to diagnose and manage any potential complications as soon as possible.

Developmental Milestones

Digestion : At 21 weeks, while the placenta still remains the primary source of the baby’s nourishment, the baby’s digestive system is gradually developing and gearing up to take over after birth. 

 The small intestine is growing longer and starting to absorb nutrients from the amniotic fluid that the baby swallows.

Red Blood Cells:

Before now, the development of your baby’s red blood cells has been mostly attributed to the liver. However, at this stage, the bone marrow is starting to play a significant role in this process. As your pregnancy progresses, around 24 weeks, the bone marrow will become the main producer of your baby’s red blood cells.


Around this time, your baby’s eyelids, which had been closed and fused together since week 11, are starting to open and  separate.