Week 39 Size: Watermelon
About the size of a sweet watermelon.
Relative Visual Scale
Solid circle represents your baby's size. Dotted circle shows the full-term week 40 size threshold.
Baby's Development
The baby is 'full term.' The placenta continues to provide nutrients and antibodies, but it is reaching the end of its lifespan. The baby has a layer of fat and is ready for the outside world.
Weekly Milestones
- ✦ Water Breaking Possibility
- ✦ Placenta Antibody Transfer Complete
Your Body & Symptoms
Your cervix is ripening (softening, dilating, and thinning). Your water might break, either as a gush or a slow trickle. If this happens, contact your provider.
Common Symptoms this Week
Doctor & Care Recommendations
- ✓ If your water breaks, note the time, color, and odor, and call your doctor.
- ✓ Double-check that you have all necessary items for postpartum recovery.
- ✓ Keep walking gently to help encourage labor.
PregWeeks
CHECKLISTUltimate Hospital Bag & Birth Plan
Print-Ready PDFThe Ultimate Hospital Bag Checklist & Birth Plan PDF
Prepare for labor with confidence. Our doctor-reviewed checklists ensure you don't forget any newborn or partner essentials in the hospital delivery room.
- ✓ Clinical OB-GYN Approved List: Separate checklists detailing exactly what mom, partner, and newborn baby require for a standard 3-day recovery stay.
- ✓ 10-Second Birth Preference Builder: Minimalist visual plan templates designed to help delivery nurses digest your labor choices instantly on check-in.
- ✓ 1-Click Offline Access: High-resolution, print-ready document formatted to download directly to your mobile device for offline reference in the clinic.
Weekly Health Guides & Resources
Third Trimester Guide
Read comprehensive clinical milestones, screening checklists, and developmental guidelines for this phase.
Track & Relieve Symptoms
Learn why symptoms occur, home remedies, and clinical indicators for this week:
Food Safety Checklists
Verify safety statuses, listeria and mercury risks, and safe alternatives for:
Frequently Asked Questions: Week 39
Evidence-Based Clinical Sources for Week 39
PregWeeks is dedicated to medical transparency. Every milestone, symptom tip, and fetal development guideline for Week 39 is sourced directly from clinical guidelines published by leading obstetric authorities. Read more about our editorial methodology on our Medical Sources page.
Prevention of Group B Streptococcal (GBS) Early-Onset Disease in Newborns
CDCClinical guidelines on the recommended routine GBS screening swab at 36-37 weeks of gestation and intrapartum antibiotic prophylaxis.
View Clinical Guideline ↗Medically Indicated Late-Term and Term Deliveries (Committee Opinion No. 764)
ACOGStandard guidelines on medical criteria and timings for elective vs. medically indicated induction or delivery near the due date.
View Clinical Guideline ↗Management of Late-Term and Post-Term Pregnancies (Practice Bulletin No. 146)
ACOGClinical recommendations for fetal monitoring and labor induction timelines for pregnancies extending beyond week 40.
View Clinical Guideline ↗Get weekly pregnancy updates
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