39 weeks pregnant
At 39 weeks you are in the third trimester, and your baby measures about 51 cm from head to heel and weighs about 3.3 kg, roughly the length of a short baguette. Full term starts now, the hospital bag belongs by the door, and the 40-week visit falls between now and 40+6 in a first pregnancy.
Weighs about 3.3 kg, like a 3 kg bag of potatoes. Averages from standard growth tables; your scan gives your baby's own numbers.
Your baby at 39 weeks
Full term. Brain and lungs keep maturing right up to the birth. Most babies have turned head-down by now and have little room left to move.
How you might feel
The baby's head is engaged in many first pregnancies, with pelvic pressure, backache and tightenings that may come and go for days.
Hospital bag by the door, phones charged.
Call the maternity unit today for any change in your baby's movements, bleeding, fluid loss, a severe headache or vision changes. 13 HEALTH (13 43 25 84) in Queensland; 000 in an emergency.
What's due this week in Australia
Lodge the Parental Leave Pay and Family Tax Benefit claims
You can lodge up to 3 months before the due date through myGov → Centrelink.
38-week antenatal visit
Blood pressure, position and movements, and a conversation about what happens if you go past the due date: membrane sweep and induction options.
40-week antenatal visit (first pregnancy)
A membrane sweep is usually offered from 40 weeks, and a plan is made for monitoring past the due date.
Coming up: 41-week visit and post-dates plan
A membrane sweep is offered and the baby’s wellbeing is checked (CTG and a fluid scan).
Coming up: Induction of labour window
If labour has not started, induction is offered between 41 and 42 weeks.
Checklist for the week
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Questions about 39 weeks
How many months is 39 weeks pregnant?
About nine months; 39 weeks is full term.
What trimester is 39 weeks?
Week 39 is in the third trimester. In the Australian guidelines Hello Bub follows, the first trimester runs to 13 weeks, the second from 14 to 27 and the third from 28 weeks.
What is the difference between early term and full term?
Early term is 37 to 38 weeks and full term is 39 to 40 weeks. Babies born at full term have fewer breathing and feeding problems, which is why planned births are scheduled from 39 weeks where possible.
Written by the Hello Bub team; medical schedule follows the Australian Pregnancy Care Guidelines; last reviewed 3 November 2026.