Third trimester

Pregnancy Week 39

A practical week 39 guide covering fetal development, symptoms, nutrition, prenatal tests, baby size comparison, and warning signs to discuss with your care team.

Week 39 ยท watermelon

Fetal development

Many clinicians consider 39 weeks full term; the baby continues gaining weight.

Baby size comparison

Around week 39, baby is roughly comparable to a watermelon. Estimated size: about 20.4 inches and 156.5 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 40-42: Post-date monitoring and induction timing discussions if still pregnant.

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.

Medical disclaimer

This week-by-week pregnancy content is educational and does not replace care from a qualified healthcare professional.