🤰 Third trimester
39 weeks pregnant
Your baby is about the size of a mini watermelon
By Emma Whitfield · Pregnancy & Baby Writer
Your baby at 39 weeks
The baby is fully developed and just gaining a little more weight. The soft skull plates remain flexible for the birth. Their first poo (meconium) is ready in the bowel.
Your body at 39 weeks
The waiting game. Only about 1 in 20 babies arrive on their exact due date, so try not to fixate on it. Any reduced movements still warrant an immediate call.
Common symptoms this week
- The waiting game
- Strong Braxton Hicks
- Pelvic ache
- Emotional readiness (and impatience)
Symptom lists are typical, never exhaustive — and having none of them is normal too.
Focus this week
Keep active with gentle walking if you're comfortable, and rest when you need to. Trust that your body and baby know what they're doing.
Week 39 checklist
- Gentle walking if comfortable
- Keep monitoring movements as attentively as ever
- Plan small daily distractions — waiting is the hardest part
39 weeks pregnant: common questions
Do natural induction methods actually work?
Mostly no, on the evidence: curries, pineapple and bumpy walks have none. Nipple stimulation has some evidence, and a membrane sweep from your midwife (offered from around 40 weeks) genuinely can bring labour forward. Nothing works until your body is ready — and most things are harmless to try.
How big is my baby at 39 weeks pregnant?
At 39 weeks, your baby is approximately the size of a mini watermelon, about 50.7cm and around 3300g. These are approximate averages — every baby grows at its own pace.
What's happening at 39 weeks pregnant?
The baby is fully developed and just gaining a little more weight. The soft skull plates remain flexible for the birth. Their first poo (meconium) is ready in the bowel. For you: the waiting game. only about 1 in 20 babies arrive on their exact due date, so try not to fixate on it. any reduced movements still warrant an immediate call.
Which trimester is 39 weeks?
39 weeks pregnant is in the third trimester. The first trimester runs to the end of week 12, the second from weeks 13 to 26, and the third from week 27 to birth.
Sources & further reading
This is general information, not medical advice — every pregnancy is different. For anything that worries you, and for all your antenatal care, speak to your midwife or GP. If your baby's movements ever slow down or change, contact your maternity unit immediately, day or night. Reviewed July 2026.