Baby development at week 39
Brain and body keep fine-tuning. Amniotic fluid levels are watched clinically. Most babies arrive within a window around the due date — not on a single day.
Average size estimates for week 39 are about 50.7 cm and 3288 g — roughly small watermelon. Your ultrasound report and clinician’s dating override any website average.
What you might feel
Impatience, excitement, and exhaustion are normal. Rest is still productive.
You are in the third trimester. Two pregnancies at the same week can feel completely different — treat these notes as orientation, not a checklist you must match.
Movements in week 39
By now, many clinicians encourage intentional awareness of fetal movement. Learn your baby’s usual active window, then use Preglo’s kick counter to log a calm session. Read how to count baby kicks if you want a simple method, or the 10-kick count overview. If movements feel clearly reduced, contact your care provider — see reduced fetal movement.
What to track this week
- Symptoms, mood, sleep, and energy in your daily log
- Water intake toward a simple daily goal
- Appointment dates and questions for your care provider
- Scan dates and follow-up notes after ultrasound visits
- Kick sessions once movements feel regular — same time of day when you can
- Tightenings or early labor patterns with the contraction timer if needed
- Hospital bag checklist and “call the clinic if…” reminders
A calm next step in Preglo
Open your due week calmly in Preglo; let the app hold the timeline while you focus on comfort.
Also useful: due date calculator · all weeks · Preglo features
Nearby weeks: Week 37 · Week 38 · Week 40
Educational averages only — not medical advice. Contact your clinician for symptoms that worry you, bleeding, severe pain, or reduced movements.