What does baby look like at 39 weeks?

At 39 weeks, your baby is the size of a Watermelon — 20 in long, 3.3 kg. Fully mature in virtually all organ systems. Continues gaining weight and developing brain

What symptoms are normal at 39 weeks pregnant?

Regular mild contractions — Braxton Hicks or early labor; track them for regularity. Lower back pain intensifying — a sign the baby is pressing on the sacrum

39 Weeks Pregnant: Baby Development & What to Expect

💡 Expert tip

If your water breaks, call your provider immediately even if you have no contractions. If contractions are 5 minutes apart, lasting 60 seconds, for 1 hour — go to the hospital.

🌱 Baby's development this week

Fully mature in virtually all organ systems
Continues gaining weight and developing brain
Skull bones not fully fused — allows passage through birth canal
Ready for the world

Science fact

During vaginal birth, babies are exposed to the mother

🤰 Your symptoms this week

Regular mild contractions

Braxton Hicks or early labor; track them for regularity

Practice contractions — normal from mid-pregnancy. Stay hydrated, change position, rest.

Lower back pain intensifying

a sign the baby is pressing on the sacrum

Prenatal yoga, a support pillow, and swimming all help. Avoid standing for long periods.

Nausea

a common sign that labor is near; your body clearing the digestive tract

Try ginger tea, crackers before getting up, or vitamin B6 (10mg 3x/day). Small meals every 2 hours help.

💛 Changes in your body

Dilation and effacement ongoing
May feel the baby
further into pelvis
Contractions becoming more regular
Extreme readiness and impatience are normal

🥗 Nutrition focus

Dates (6/day) have been associated with less need for oxytocin augmentation during labor in multiple studies
Light meals only — active labor is easier on an empty or lightly filled stomach
Stay hydrated — contractions, especially false labor, are worsened by dehydration

📅 Appointment / test

39-week appointment: discuss induction preferences and timing with your provider. Most offer elective induction at 39 weeks.

✅ This week's checklist

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Apply the 5-1-1 rule for hospital: contractions every 5 min, lasting 1 min, for 1 hour

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Rest between contractions if in early labor at home

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Call your provider immediately if water breaks, you have heavy bleeding, or baby stops moving

Track your pregnancy week by week

Interactive guide · 40 weeks · Fruit size visualizations · Personalized tips

Explore Week 39 in the Interactive Guide →

Week 39: Full term! The vast majority of organs are now fully mature.

🌱 Baby's development this week

🤰 Your symptoms this week

💛 Changes in your body

🥗 Nutrition focus

✅ This week's checklist

Track your pregnancy week by week