40 weeks pregnant
At 40 weeks pregnant, your baby is about the size of a watermelon: around 51.2 cm head to heel and 3.46 kg. Due date week. Only a small share of babies arrive on their exact due date, so any day now is normal.
Your baby at 40 weeks
Due date week. Only a small share of babies arrive on their exact due date, so any day now is normal.
| Size | About the size of a watermelon |
|---|---|
| Length | 51.2 cm head to heel |
| Weight | 3.46 kg |
Your baby is ready to be born. The average baby at 40 weeks weighs about 3.4 kg and is about 51 cm long, but healthy babies come in a wide range of sizes. The skull bones are not yet joined, so your baby's head can mould gently during birth. Your baby is still receiving antibodies from you to protect against infection.
How far along are you at 40 weeks?
At 40 weeks pregnant you are in the ninth month of your pregnancy and the third trimester. This is the week of your due date, though only about 1 in 20 babies arrive exactly on it. Doctors count pregnancy from the first day of your last period, not from conception, so at 40 weeks your baby has been growing for about 38 weeks. Not sure of your dates? Use our due date calculator.
Your body at 40 weeks
You may feel pelvic pressure and a burst of nesting energy. Learn the signs of labour and when to call.
Common symptoms at 40 weeks
Every pregnancy is different, and you may have some, all or none of these.
- Pelvic pressure. Your baby is low and ready.
- Braxton Hicks. They may turn into the real thing at any time.
- Losing your mucus plug. A show can happen days before labour.
- Backache. May be a sign labour is close.
- Tiredness and frustration. Very common when you reach your due date.
- Bursts of energy. Some women feel a burst of energy before labour.
Your checklist for week 40
- Go to your due-date appointment and ask about your plan if your baby doesn't arrive.
- Discuss a membrane sweep, and when induction would be offered.
- Keep tracking your baby's movements every day.
- Keep your bag, notes and phone charger ready.
- Rest, and let friends and family know you'll share news when you are ready.
Tip of the week: When your due date comes and goes
A due date is an estimate; most babies arrive between 37 and 42 weeks. If you go past 40 weeks, your doctor will usually offer a membrane sweep and monitoring, and will discuss induction, usually between 41 and 42 weeks, because the risks to the baby rise slowly after that. Keep tracking movements and call straight away if they change.
For your partner
You're on call now.
- Keep your phone charged and the tank full
- Time contractions with the app
- Stay calm and keep her company
When to call your doctor at 40 weeks
Contact your doctor, midwife or maternity unit the same day if you have:
- Your baby is moving less or the pattern has changed. Call straight away, day or night.
- Your waters break, bleeding, constant pain, a severe headache or vision changes.
Call your doctor or hospital straight away for bleeding, severe pain, fluid leaking, severe headache or vision changes, or fewer baby movements.
Questions about 40 weeks pregnant
Is it safe to go overdue?
Going past your due date is common and usually safe in the short term. After 41 to 42 weeks, the placenta may work less well, so doctors usually recommend induction around then. You'll be monitored more closely while you wait.
What is induction of labour?
Induction means starting labour artificially, usually with a pessary or gel to soften the cervix, then breaking the waters and, if needed, a hormone drip to bring on contractions. Your doctor will explain the methods and what to expect.
Is a caesarean needed if I'm overdue?
No. Being overdue on its own doesn't mean you need a caesarean. Most women who are induced go on to have a vaginal birth. A caesarean may be recommended if there are concerns about you or your baby.