Pregnancy Week 4

Fetal development

The tiny heart tube is developing, and the foundations of the brain and spine are forming.

Baby size comparison

Around week 4, baby is roughly comparable to a blueberry. Estimated size: about 0.5 inches and 0.04 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 4-8: Confirm pregnancy, review medications, estimate due date, and discuss early symptoms.

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.