Trimester 3
39 Weeks Pregnant
In week 39, your baby is putting on weight quickly and fine-tuning their lung and brain function. They are becoming more responsive to light and sound from the outside world as they prepare for the big transition to life outside.
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Your baby is the size of a Mini watermelon
51 cm
Length
3.3 kg
Weight
Week 1Week 13 - End of Trimester 1Week 27Week 42
Baby's Development This Week
In week 39, your baby is putting on weight quickly and fine-tuning their lung and brain function. They are becoming more responsive to light and sound from the outside world as they prepare for the big transition to life outside.
- The baby is officially full term!
- The brain has 30 billion neurons.
- The chest wall is developed enough for effective breathing.
- Reflexes are coordinated — baby can grasp, suck, blink, and turn the head.
- The fetus fills the entire uterus.
- About 50.7cm — the size of a watermelon.
Your Symptoms at Week 39
As you progress through week 39, you may feel more physical strain as your baby grows. Back pain and difficulty finding a comfortable sleeping position are common. Keep your feet up when you can and take pride in how far you've come in this incredible process.
Intense Braxton Hicks or early labor contractions
Time them carefully — call your provider if they follow a pattern. (severe)
Time them carefully — call your provider if they follow a pattern. (severe)
Pelvic pressure
The baby is deep in the pelvis — this is normal and a sign of readiness. (severe)
The baby is deep in the pelvis — this is normal and a sign of readiness. (severe)
Nausea or diarrhea
May be an early sign of labor; stay hydrated. (mild)
May be an early sign of labor; stay hydrated. (mild)
Restlessness and anxiety
Practice breathing exercises and visualization. (moderate)
Practice breathing exercises and visualization. (moderate)
Bloody show
Normal sign that labor may be near; call if heavy bleeding. (mild)
Normal sign that labor may be near; call if heavy bleeding. (mild)
When to Call Your Doctor
- Contractions 5 minutes apart, lasting 1 minute, for 1 hour
- Water breaks (note time, color, and smell)
- Bright red bleeding
- Sudden decrease in movement
- Feeling the urge to push
Week 39 Checklist
- ✓Attend weekly prenatal visit (essential)
- ✓Keep your phone charged and hospital bag by the door (essential)
- ✓Rest and sleep as much as possible (essential)
- ✓Review the 5-1-1 rule with your partner (essential)
- ✓Make sure the car seat is installed correctly (essential)
Frequently Asked Questions
Continue Your Pregnancy Journey — Week 39
← →
Week 38 of Pregnancy
Review what happened last week with your baby's development
← →
Week 40 of Pregnancy
What's coming next week — new developments and symptoms to expect
Guide
Third Trimester Overview
Everything happening during your third trimester — symptoms, tests, and milestones
Symptom
Braxton Hicks Contractions
How to tell practice contractions from the real thing
Symptom
Swollen Feet & Ankles
Normal swelling vs. warning signs of preeclampsia
Tool
Contraction Timer
Time contractions to know when to head to the hospital
Related
Group B Strep Test
Routine test between weeks 35–37 — what a positive result means
Nutrition
Third Trimester Nutrition
Foods for energy, labor prep, and healthy final weight gain
Medical Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for personalized guidance about your pregnancy.