Third trimester

Weeks 28–40

Growth and preparation — for the baby's lungs, and for you.

Illustration is stylised and not to scale between weeks.

What this stretch is really about

The third trimester is mostly growth — your baby roughly doubles in weight — and preparation, for the lungs and for you. Visits become more frequent because this is when blood pressure, growth and position matter most.

This is also the stretch where knowing what is urgent matters. Reduced movement is never something to sleep on and see about in the morning; it is a same-day call, every time.

The milestones

Week 32

Weeks 28–35

Growing fast, running out of room

Mostly weight now — the baby roughly doubles between 28 and 36 weeks, laying down the fat that will regulate temperature after birth. Bones harden, though the skull stays deliberately soft for the journey out. Visits become more frequent.

Growth scan if measurements suggest it
Whooping cough vaccination
Reduced movement is always an emergency, never a wait-and-see

Week 40

Weeks 36–40

Head down, and ready

Most babies settle head-down by 36 weeks; if yours has not, there are options and they are worth discussing early. From 37 weeks the pregnancy is term. Your due date is an estimate — only a small minority of babies arrive exactly on it.

Position check, and a plan if the baby is breech
Know true labour from Braxton Hicks
Monitoring continues past 40 weeks

For general understanding only. Lengths, weights and size comparisons are typical averages — your baby may be bigger or smaller and still be perfectly healthy. Only your own scan can tell you where yours is.

Your appointments and checks

More frequent visitsFortnightly, then weeklyBlood pressure, urine, growth and position — the things that change fast at the end.

Whooping cough vaccineFrom 28 weeksAntibodies cross the placenta and protect the baby in the first weeks of life.

Growth scanIf indicatedChecks growth, fluid and blood flow when measurements or history suggest a closer look.

Position checkFrom 36 weeksMost babies are head-down by now. If yours is not, there are options — and they work better discussed early.

What you may feel

Breathlessness, heartburn and poor sleep
Braxton Hicks — irregular, and they settle when you move
Swelling of the feet by the end of the day
Pelvic pressure as the head engages
A strong urge to clean and organise everything

Call today — don't wait for the next appointment

Reduced or changed movement — call the same day, do not wait
Severe headache, visual disturbance, or pain under the ribs
Bleeding, or fluid leaking
Contractions before 37 weeks
Sudden swelling of the face, hands or feet

Your week in detail

Find your week

Week 28

A brinjal

Not sure which week you are in?

Pick the first day of your last period and we will work out the week and your due date.

37.6 cmLength

1 kgWeight

T3Trimester

Your baby

The third trimester begins. The baby can blink, and is beginning to build the fat stores that will regulate temperature after birth.

You this week

Appointments become more frequent. Braxton Hicks are more noticeable.

Care & checks

Glucose tolerance test and anti-D, if applicable, are typically around now. Start counting movements daily.

Second trimester The whole journeyThird trimester

While you are waiting

Nobody should be guessing at 2am.

These trimester guides cover what is normal week by week, and what needs looking at the same day. Anything in the second group should never wait on an inbox — go straight to your nearest maternity unit.

Contact the clinic See all services

This page is general information, not medical advice. Nothing here can diagnose you or replace an assessment of your own history, examination and results. If something here matches what you are experiencing, the next step is a consultation — not a conclusion. If you are in severe pain, bleeding heavily, or feel unwell, seek urgent care rather than waiting for an appointment. Awaiting final clinical review before publication.