Third trimester · Week 39 of 40
39 weeks pregnant: the size of a watermelon (small)
Full term. The brain is still developing and will keep growing after birth.
Reviewed against ACOG, NHS and WHO guidance · Updated November 2026
Typical size
About 50 cm · 3.3 kg
98% of the way to your due date
Your baby this week
Full term. The brain is still developing and will keep growing after birth.
Your body this week
You may feel impatient and uncomfortable — totally normal.
Tip for week 39
Call your provider if your waters break, even without contractions.
Carry this guide in your pocket
Mamivaa is a free pregnancy app with a week-by-week tracker, vitamin and water reminders, a food scanner and a baby checklist.
Start freeThis guide offers general information and does not replace advice from your doctor or midwife. If something feels wrong, contact your provider or emergency services.