Third trimester
38 weeks pregnant
Your baby is about the size of a leek
By Clever Mum Parenting · Parenting guides
How big is the baby at 38 weeks pregnant?
At 38 weeks pregnant, your baby is about the size of a leek, roughly 49.8cm and around 3100g. The baby's organs are ready for life outside. They're building the last of their fat stores, and their grip is strong. Brain and lung development continues right up to birth. These are typical averages — your midwife's measurements are the ones that matter for your pregnancy.
What might you feel at 38 weeks?
Most people at 38 weeks notice some mix of the symptoms below — and plenty notice none of them. Nesting urges, restlessness and impatience are all common now. Some experience a burst of energy; others just feel ready. Keep monitoring movements. None of this is a diagnosis; contact your midwife if something worries you.
Common symptoms this week
- Restlessness and impatience
- Nesting urges
- Pelvic pressure
- Sleep in short instalments
Symptom lists are typical, never exhaustive — and having none of them is normal too.
What should you do at 38 weeks pregnant?
The useful job this week is practical, not medical. Rest as much as you can and keep your phone charged. Re-read your notes on early labour so you feel prepared rather than anxious. Pair it with the NHS week-by-week guide if you want a second description of the same stage.
Week 38 checklist
- Attend your 38-week appointment
- Keep phones charged and the plan visible
- Re-read your early-labour notes so the first hours feel familiar
What else is useful at 38 weeks?
Use the week page for size and symptoms; use the guides below for the decisions that actually sit in this window — pay, packing, car seats, labour signs.
38 weeks pregnant: common questions
How do I know when to go to hospital in labour?
Call your maternity triage first — the usual guidance for first babies is contractions roughly every 3 minutes lasting about a minute (many units say 3-in-10), or straight away if your waters break, you're bleeding, or the baby's movements change. When in doubt, call: that's what triage is for.
How big is my baby at 38 weeks pregnant?
At 38 weeks, your baby is approximately the size of a leek, about 49.8cm and around 3100g. These are approximate averages — every baby grows at its own pace.
What's happening at 38 weeks pregnant?
The baby's organs are ready for life outside. They're building the last of their fat stores, and their grip is strong. Brain and lung development continues right up to birth. For you: nesting urges, restlessness and impatience are all common now. some experience a burst of energy; others just feel ready. keep monitoring movements.
Which trimester is 38 weeks?
38 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 August 2026.