Trimester 3
Week 39
Your baby is about the size of a small pumpkin.
Length: 50.7 cm · Weight: 3300 g
Common this week: Intense Braxton Hicks, Pelvic pressure, Back pain, Nesting, Emotional intensity, Loss of mucus plug.
Baby development
- The baby is fully developed and ready for birth.
- The placenta is passing peak nutrients and antibodies.
- Fat stores are well established for temperature regulation.
- The baby's skull bones are still separated — they will overlap slightly during birth.
Changes for you
- Every contraction is evaluated: is this the one?
- Cervical dilation and effacement should be progressing.
- The baby may feel very low — walking can be waddling.
- Emotions are a mix of excitement, nervousness, and readiness.
Tips
- Know the difference between Braxton Hicks and real labour: real contractions are regular, grow stronger, and don't ease with movement.
- Stay hydrated and rest as much as possible.
- When real labour starts: time contractions and call the hospital when they are 5 minutes apart.
- Trust your body — it has been preparing for this for 39 weeks.
Appointments
- Weekly antenatal check — your provider may offer a stretch and sweep.
Warning signs
- Decreased fetal movement — do not wait, call your hospital now
- Heavy bleeding
- Signs of preeclampsia
Australian notes
- A membrane sweep (stretch and sweep) is commonly offered from 39 weeks in Australia to encourage natural labour onset. It's done by your midwife or OB in the clinic.
- Induction of labour may be discussed if you go past 41 weeks. RANZCOG recommends discussing this with your provider.