Third trimester

Third trimester guide: weeks 28 to birth

By Nine Moons EditorialMedically reviewed by Professor Dr FarhatUpdated 10 Oct 20267 min read

Quick answer

The third trimester runs from week 28 until birth. Your baby gains most of their weight, practises breathing, and usually turns head down by about 36 weeks. Expect backache, heartburn, breathlessness, swollen ankles, poor sleep and practice contractions. Keep track of your baby's movements, sleep on your side, and learn the signs of labour and pre-eclampsia.

Key facts

Weeks	28 to birth
Head down	Most babies by 36 weeks
Baby's weight	From about 1 kg to about 3.4 kg
Sleep	On your side from 28 weeks
Hospital bag	Packed by 36 weeks

Your baby: growing and turning

Your baby more than triples in weight, their brain grows fast, and the lungs mature. Most turn head down, ready for birth.

Turning head down. Most babies settle head down by about 36 weeks. About 3 or 4 in 100 are still bottom first at term, and your doctor may offer to turn them.

If your baby is bottom first (breech) at 36 weeks, your doctor may offer to turn them by gently pressing on your tummy (external cephalic version), or discuss a caesarean.

Common symptoms and relief

Heartburn: small meals, avoid spicy or fatty food late at night, raise the head of the bed.
Back and pelvic pain: see sleep and back pain.
Swollen ankles: put your feet up and keep moving. Sudden swelling of the face or hands needs checking.
Breathlessness: common as the womb pushes up. Sudden or severe breathlessness isn't.
Braxton Hicks: painless, irregular tightenings. Read real contractions or practice?
Peeing more and leaking a little when you cough: start pelvic floor exercises.
Tingling hands (carpal tunnel) and poor sleep.

Appointments

You'll be seen more often. Checks include blood pressure, urine, your bump size and baby's position. Some countries test for group B strep at 35 to 37 weeks. Ask about the whooping cough vaccine if you haven't had it.

Getting ready

Pack your hospital bag and fit the car seat.
Learn the stages of labour and pain relief options.
Read up on breastfeeding and recovery after birth.
Share your plan with your partner using partner mode.

Warning signs

Call straight away for reduced movements, bleeding, fluid leaking, severe headache or vision changes, intense itching of hands and feet, or regular contractions before 37 weeks. See all warning signs.

Frequently asked questions

Do babies move less near the end?

No. The type of movement changes, but they shouldn't slow down. Call if they do.

Can I fly in the third trimester?

Many airlines ask for a doctor's letter after 28 weeks and stop flying at about 36 weeks for one baby, 32 weeks for twins.

When does the baby 'drop'?

In a first pregnancy, often 2 to 4 weeks before labour. It can happen later in later pregnancies.

Sources

NHS: Week-by-week guide
RCOG Green-top 20a: External cephalic version and reducing breech
NICE NG201: Antenatal care

General information, not medical advice. Medical disclaimer · How we review content

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