At 29 weeks your baby is about 38.5 cm and 1.2 kg — roughly a butternut squash — and is drawing around 250 mg of calcium from you every day as the skeleton hardens. For you, heartburn and Braxton Hicks contractions both tend to intensify around now.
The short answer: the skeleton is actively hardening, pulling roughly 250 mg of calcium from your body daily, while subcutaneous fat continues building for temperature regulation after birth and the head grows to accommodate rapid brain development. For you, the growing uterus pushes the stomach further up, often intensifying heartburn, and Braxton Hicks contractions may become more noticeable — still irregular and generally painless, just more present than before.
Your baby this week
The skeleton is hardening from soft cartilage into true bone at a faster pace now, drawing roughly 250 mg of calcium a day from your body to do it — a real, measurable demand that is part of why calcium intake matters more through the third trimester. Subcutaneous fat continues to build actively, filling out the frame and preparing baby to regulate their own body temperature once outside the womb.
The head keeps growing to make room for a brain that is developing at a genuinely striking pace right now, with billions of neural connections forming as the third trimester progresses. Movements remain strong and frequent, and the pattern established over recent weeks should keep feeling broadly familiar even as space continues to tighten.
Your body this week
Your belly keeps growing steadily, and heartburn and a feeling of heaviness after meals often become more noticeable now — the uterus is pushing the stomach further upward, adding mechanical pressure on top of the effect progesterone already has on the valve that normally keeps stomach acid down. Smaller, more frequent meals and staying upright for a while after eating both genuinely help, more than most people expect.
Braxton Hicks practice contractions may also intensify — becoming more noticeable, though they should stay irregular and generally painless. If a tightening pattern starts to feel regular, increasingly painful, or comes with lower back pain, pelvic pressure, or fluid loss, that combination is worth same-day assessment, especially since it is still before 37 weeks.
Tests and appointments
Most care pathways have nothing scheduled precisely at 29 weeks, though appointments are generally becoming more frequent as the third trimester progresses, often moving toward every two weeks from around 30 weeks onward.
✅ Worth doing this week
- Add more calcium-rich foods — dairy, sesame, almonds, or a fortified alternative if dairy-free
- Switch to smaller, more frequent meals to ease heartburn and bloating
- Stay upright for 30–60 minutes after eating rather than lying down right away
- Note the pattern of any tightenings — irregular and painless is expected, regular and painful is not
- Ask about safe antacids if heartburn is disrupting sleep or meals
When to call your doctor
Call the same day if: tightenings become regular, increasingly frequent or painful, or come with lower back pain, pelvic pressure, bleeding, or fluid loss — this combination needs assessing for preterm labour, especially before 37 weeks. Also call for reduced movement, a severe headache with visual disturbance, sudden swelling of the face or hands, or a temperature above 38°C.
FAQ — 29 weeks pregnant
How much calcium does the baby need at 29 weeks?
Around 250 mg a day is drawn from the mother's body as the skeleton hardens from soft cartilage into true bone, a process that accelerates through the third trimester. This is one reason calcium-rich foods — dairy, sesame, almonds, fortified alternatives — matter more now, alongside any supplement your care provider has recommended.
Why does heartburn get worse around 29 weeks?
The growing uterus keeps pushing the stomach further upward, adding mechanical pressure on top of the effect progesterone already has of relaxing the valve that normally keeps stomach acid down. Together these make heartburn both more frequent and more intense for many people through the third trimester. Smaller, more frequent meals and staying upright after eating are the two changes that help most.
Are Braxton Hicks contractions supposed to get stronger now?
They often become more noticeable from here, sometimes even mildly uncomfortable, but they should stay irregular, not build in a consistent pattern, and remain painless overall. Contractions that become regular, increasingly painful, or come with lower back pain, pelvic pressure, or fluid loss are a different signal and need same-day assessment, particularly before 37 weeks.
How big is the baby at 29 weeks?
About 38.5 cm and 1.2 kg — roughly a butternut squash. Subcutaneous fat continues building actively, which will help with temperature regulation after birth, while the head keeps growing to accommodate a brain that is developing at a striking pace right now.
Week 29 at a glance
At 29 weeks your baby is about 38.5 cm and 1.2 kg, actively hardening bones that draw roughly 250 mg of calcium from you daily, while fat stores build and the head grows for rapid brain development. For you, heartburn often intensifies as the uterus pushes the stomach further up, and Braxton Hicks contractions may become more noticeable while staying irregular and generally painless — a different pattern from the regular, painful tightening that needs same-day assessment.
Inside Baby Novum: the safe-foods guide rates over 240 items by trimester, useful for working out what sits comfortably alongside heartburn without giving up on calcium-rich options.