Week 39 of pregnancy
39 Weeks Pregnant
Third trimester
Baby size
About the size of a mini watermelon
50.7 cm
What's developing
The baby is full term. Fat continues to build under the skin to help regulate body temperature after birth.
Common symptoms this week
- Pelvic pressure
- Braxton Hicks
- Cervical changes
- Diarrhea
This is an estimate for information only — only about 1 in 20 babies arrive on their due date. Always confirm dates with your midwife or doctor.
How big is a baby at 39 weeks?
Baby growth chart
Typical fetal length and weight from week 8 to week 40.
Length
cmWeek 39: 50.7 cm
Weight
gramsWeek 39: 3.29 kg
Typical averages based on Hadlock / ACOG references. Weeks 8–20 use crown–rump length; weeks 21–40 switch to crown–heel — that's the small jump you'll see mid-chart. Real babies vary — your ultrasound is the reliable number for you.55
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