At 34 weeks your baby is about 44 cm and 2.1 kg — roughly a cantaloupe melon — with enough fat built up now to regulate their own body temperature, and lungs in their final stage of preparation.
The short answer: baby can now regulate their own body temperature thanks to a thickened layer of fat, most of the fine lanugo hair has disappeared, and active breathing practice with amniotic fluid continues strengthening the lungs. For you, the uterus has reached its peak height, pressing on the ribs and diaphragm, the belly button may pop out or flatten, and mild blurry vision from fluid shifts is common.
Your baby this week
The lungs are in their final stage of preparation, and baby actively inhales and exhales small amounts of amniotic fluid to strengthen the muscles used for breathing — genuine rehearsal for that first breath of air. The layer of subcutaneous fat is now thick enough that baby can regulate their own body temperature, a real physiological milestone rather than just visual plumpness.
Most of the fine lanugo hair that covered the body in earlier months has disappeared by now, and the protective vernix coating has thickened, helping baby slip more easily through the birth canal during delivery.
Your body this week
The uterus is at the peak of its height now, which can mean real pressure on the ribs and diaphragm. Many people notice their belly button has flattened out completely or even turned outward — a harmless effect of the abdominal wall stretching, which returns to its previous shape within months after birth.
Mild blurry vision or dryness in the eyes is common now, caused by fluid retention slightly changing the shape of the cornea, and it typically resolves within weeks after birth. Taking screen breaks and resting with closed eyes when it happens genuinely helps. That said, blurring that is sudden, severe, or comes with a headache or swelling is a different signal and needs same-day assessment.
Constipation often continues to be a factor this late in pregnancy too, as the growing uterus presses on the intestines and slows things down. Staying well hydrated and keeping fibre intake up remain the two most reliable habits, more so than any single food or remedy.
Tests and appointments
Most care pathways have nothing specific scheduled precisely at 34 weeks, though appointments remain frequent through the rest of the third trimester.
✅ Worth doing this week
- Rest your eyes regularly if dryness or blurriness shows up — screen breaks genuinely help
- Keep the hospital bag visible and ready — knowing it is done can ease a surprising amount of background anxiety
- Learn the difference between ordinary blurry vision and the warning signs that need a call
- Keep tracking baby's movement pattern daily
- Talk through your birth plan one more time if anything has changed
When to call your doctor
Call the same day if: vision changes are sudden, severe, or come with a headache, or if swelling appears suddenly on your face or hands — this combination needs assessment for preeclampsia. Also call for reduced movement, bleeding, severe abdominal pain, regular tightenings before 37 weeks, or a temperature above 38°C.
FAQ — 34 weeks pregnant
Why is my vision a bit blurry at 34 weeks?
Mild, gradual blurring or dryness in the eyes is a recognised effect of pregnancy hormones, caused by fluid retention that slightly changes the shape of the cornea — it typically resolves within weeks after birth and is not harmful in itself. That said, vision changes are also a recognised sign of preeclampsia, so any blurring that comes on suddenly, is severe, or comes with a headache or swelling needs same-day assessment rather than assumed to be routine.
Is it normal for the belly button to pop out at 34 weeks?
Yes — an outie belly button, or one that has flattened out completely, is a very common and harmless effect of the abdominal wall stretching to accommodate the growing uterus. It typically returns to its previous shape within months after birth and needs no treatment.
Why does baby practise breathing with amniotic fluid?
Baby actively inhales and exhales small amounts of amniotic fluid, which strengthens the muscles used for breathing and helps the lungs finish preparing for that first real breath of air after birth. It is a genuine rehearsal, not a risk — the fluid moves in and out of the airway and lungs safely throughout.
How big is the baby at 34 weeks?
About 44 cm and 2.1 kg — roughly a cantaloupe melon. Enough subcutaneous fat has built up that baby can now regulate their own body temperature, most of the fine lanugo hair has disappeared, and the protective vernix coating has thickened to ease the passage through the birth canal.
Week 34 at a glance
At 34 weeks your baby is about 44 cm and 2.1 kg, able to regulate their own body temperature, with most lanugo gone and lungs in their final stage of preparation through active breathing practice. For you, the uterus is at its peak height, the belly button may pop out or flatten, and mild blurry vision is common — though a sudden or severe change is a different signal worth calling about.
Inside Baby Novum: track symptoms like vision changes and swelling day to day, so a genuine pattern shift stands out clearly instead of blending into normal third-trimester discomfort.