4 min read · Around weeks 36–40 of pregnancy
Nine months pregnant.
The hospital bag is waiting. Tiny clothes are folded. And every unfamiliar sensation can suddenly make you wonder:
Is today the day?
Your baby already looks much like the newborn you are about to meet, but these final weeks still matter. Growth continues, the lungs and other body systems finish maturing and your baby keeps preparing for the enormous transition from womb to world.
How big is your baby at 9 months pregnant?
At around 36 weeks, an average fetus measures approximately 47.4 cm from head to heel.
By around 40 weeks, this is approximately 51.2 cm.
These are averages rather than targets. Babies naturally come in different sizes, and your maternity team will use appropriate clinical measurements to monitor your individual pregnancy.
Your baby's lungs are preparing for that first breath
By around 36 weeks, the lungs are often mature enough for a baby born at this stage to breathe without assistance, although every baby and birth is different.
Inside the womb, your baby still receives oxygen through the placenta.
That first real breath comes after birth.
Your baby is getting plumper
Your baby continues storing fat beneath the skin during the final weeks.
Those stores help with temperature regulation and energy after birth and give newborns their increasingly rounded appearance.
Your baby may be positioned for birth
By this stage, many babies are head down.
If your baby is breech or in another position, your healthcare team will discuss what that means for your birth and any options that are appropriate for you.
Movement still matters right up to birth
Your baby has much less space than earlier in pregnancy, so movements may feel different.
You might notice strong rolls, stretches, pushes and smaller shifts rather than dramatic turns.
But movements should not simply slow down because your baby has run out of room.
You should continue feeling movement right up to and during labour.
If your baby moves less than usual, stops moving or their normal pattern changes, contact your maternity care team immediately.
Your body is preparing too
You may notice Braxton Hicks contractions, pressure lower in your pelvis, backache, sleeping difficulties or increased discomfort as your due date approaches.
Some changes may simply be part of late pregnancy. Others can signal that labour is beginning.
Read our guide to early signs of labour and when to call your maternity team.
What if you reach your due date?
A due date is an estimate rather than an appointment.
If pregnancy continues beyond it, your maternity team will explain the monitoring and options appropriate to your situation.
Do not try to force labour using internet remedies or supplements without first speaking with your healthcare professional.
Hello World Kit | 0–6 months
The chapter you have been preparing for is almost here. The Hello World Kit brings together thoughtfully selected visual, sensory, motor and memory pieces for your baby's first six months — ready for those quiet awake moments after you finally meet.
Explore the Hello World Kit
Frequently asked questions
How big is a baby at 36 weeks pregnant?
At around 36 weeks, an average fetus measures approximately 47.4 cm from head to heel, although individual growth varies.
How big is a baby at 40 weeks?
At around 40 weeks, an average fetus measures approximately 51.2 cm from head to heel.
Should my baby move less at nine months pregnant?
No. The type of movement may change as space becomes limited, but you should continue feeling your baby move according to their usual pattern right up to and during labour.
What should I do if my baby's movements change?
Contact your maternity care team immediately if movements are reduced, stop or change from your baby's usual pattern.
Is my due date the exact day my baby will arrive?
No. A due date is an estimate. Your healthcare team will explain what happens if your pregnancy continues beyond it.
The Owloo approach
You have spent months wondering what your baby will look like.
Soon you will know.
One final stretch. One final kick. Then hello.
Written by Tina Krapez, Owloo Co-founder & COO
Tina Krapez is the Co-founder and COO of Owloo, where she helps create thoughtful products and educational resources supporting families from pregnancy through their baby's earliest development.
Sources and further reading
