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Third Trimester (Weeks 28 - 40) Week 31 of 40
Fetal Size Comparison

Week 31 Size: Coconut

About the size of a coconut.

Length 41.1 cm 16.2 inches
Weight 1500 g 52.9 oz

Relative Visual Scale

Solid circle represents your baby's size. Dotted circle shows the full-term week 40 size threshold.

Inside The Womb

Baby's Development

The baby is going through a major growth spurt. The nervous system can process more complex information. The baby can turn their head from side to side and is moving frequently.

Weekly Milestones

  • Complex Sensory Processing
  • Fetal Head Turning
Maternal Health

Your Body & Symptoms

Your breasts may leak yellow, sticky fluid called colostrum (early milk). Your lung capacity is restricted, making you catch your breath easily.

Common Symptoms this Week

Leaking colostrum Shortness of breath Braxton Hicks Dry, itchy belly

Doctor & Care Recommendations

  • Use nursing pads in your bra if leakage is bothersome.
  • Take slow, deep breaths when you feel short of breath.
  • Inquire about infant CPR classes in your area.
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PregWeeks

CHECKLIST

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Prepare for labor with confidence. Our doctor-reviewed checklists ensure you don't forget any newborn or partner essentials in the hospital delivery room.

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Weekly Health Guides & Resources

Trimester Guide

Third Trimester Guide

Read comprehensive clinical milestones, screening checklists, and developmental guidelines for this phase.

Explore Trimester →
Common Symptoms

Track & Relieve Symptoms

Learn why symptoms occur, home remedies, and clinical indicators for this week:

Pregnancy Nutrition

Food Safety Checklists

Verify safety statuses, listeria and mercury risks, and safe alternatives for:

Full Nutrition Guide →

Frequently Asked Questions: Week 31

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Evidence-Based Clinical Sources for Week 31

PregWeeks is dedicated to medical transparency. Every milestone, symptom tip, and fetal development guideline for Week 31 is sourced directly from clinical guidelines published by leading obstetric authorities. Read more about our editorial methodology on our Medical Sources page.

Gestational Hypertension and Preeclampsia (Practice Bulletin No. 202)

ACOG

Clinical guidelines for monitoring blood pressure, proteinuria, and warning signs of preeclampsia during third-trimester prenatal care.

View Clinical Guideline

Fetal Growth Restriction (Practice Bulletin No. 219)

ACOG

Recommendations for measuring fundal height, tracking fetal growth scales, and diagnosing growth limitations in the third trimester.

View Clinical Guideline

WHO Guidelines on Physical Activity and Sedentary Behaviour

WHO

Global physical activity standards for pregnant women to support circulation, minimize excessive weight gain, and prepare for labor.

View Clinical Guideline
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🏥 Medical Disclaimer

PregWeeks is an educational planning tool and does not provide clinical diagnoses or medical advice. Always consult your obstetrician or healthcare professional for health concerns.