Pregnancy Week 21

Fetal development

Swallowing and digestive practice continue, and movement patterns may be clearer.

Baby size comparison

Around week 21, baby is roughly comparable to a papaya. Estimated size: about 10.9 inches and 15.2 ounces, with natural variation.

Common symptoms

• Energy, appetite, sleep, and digestion may change.
• Some people notice cramps, bloating, skin changes, or back discomfort.
• Symptoms vary widely, and absence of a symptom does not always mean a problem.

Tests and appointments

• Weeks 15-22: Second-trimester serum screening or AFP depending on prior screening choices.
• Weeks 18-22: Anatomy ultrasound to review fetal growth and major structures.

Nutrition focus

• Include protein, fiber-rich carbohydrates, colorful produce, and healthy fats.
• Ask about iron, folic acid, iodine, vitamin D, choline, and omega-3 needs.
• Follow local food-safety advice for fish, caffeine, unpasteurized foods, and supplements.

Warning signs

• Call your care team for heavy bleeding, severe pain, fever, fainting, severe headache, vision changes, fluid leakage, or decreased fetal movement later in pregnancy.
• Emergency symptoms should be handled urgently according to local medical guidance.