21 Weeks Pregnant: What to Expect This Week
Twenty-one weeks pregnant and your baby has fully formed eyebrows and eyelids, and is developing distinct sleep and wake cycles that you may start to notice as patterns in their movement.
Baby at Week 21: Size of a carrot
Baby's Development at 21 Weeks
The eyebrows and lids are fully formed. Baby experiences regular sleep cycles, including REM sleep — which means baby may already be dreaming. The bone marrow has taken over production of red blood cells from the liver. The digestive system is processing small amounts of amniotic fluid, and meconium (baby's first bowel movement) is beginning to form in the intestines. Baby's movements are becoming more coordinated and purposeful.
Your Body at 21 Weeks Pregnant
Kicks and movements are typically stronger and more regular by week 21. Heartburn and indigestion often continue. Some people experience stretch marks appearing on the abdomen, hips, and breasts as skin expands rapidly — genetics plays a large role in who gets them. Pelvic girdle pain (PGP) — discomfort around the pelvis and hips — begins for some people around this stage.
Tips for Week 21
- Notice your baby's active times and track their patterns — it will help you identify changes later.
- For pelvic girdle pain, keeping knees together when getting in and out of the car, and sleeping with a pillow between your knees, makes a big difference.
- Look into birthing class options — hypnobirthing, Lamaze, and hospital-run classes are all worth considering.
- Omega-3 fatty acids (from salmon, sardines, or a supplement) support brain development throughout the second half of pregnancy.
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Frequently Asked Questions
How often should I feel baby move at 21 weeks?
At 21 weeks, movement isn't yet regular enough to count formally. Most providers start recommending kick counts from 28 weeks. What's important is getting to know your baby's normal pattern — and contacting your provider if you notice a significant decrease in movement compared to what's typical for your baby.
What is pelvic girdle pain in pregnancy?
Pelvic girdle pain (PGP), sometimes called symphysis pubis dysfunction (SPD), is pain around the pelvis, hips, and lower back caused by increased joint mobility during pregnancy. It affects up to 20% of pregnant people. Physiotherapy, a pelvic support belt, and modifications to how you move (keeping legs together when turning in bed) can significantly help.
Track baby's movement patterns
Hello, baby's kick counter helps you build a baseline of your baby's movements — and your partner sees your counts in real time.
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