Pregnancy Week 40: Your Due Date — What Happens Next

Quick answer: Your due date is an estimate — only around 5% of babies arrive on it, and many first babies come later. Your midwife will offer a membrane sweep at your 40-week appointment, and induction is discussed at 41 to 42 weeks. Call your maternity unit immediately if your baby's movements reduce or change.

What parents need to know

You've reached your due date — 40 weeks! Whether you're reading this while still waiting for your baby, or looking back on your pregnancy journey, this final post in our week-by-week series marks the end of an extraordinary 40 weeks. But a due date is just an estimate, and many babies — particularly first babies — arrive after 40 weeks. Whenever your baby arrives, you're ready.

How big is your baby at 40 weeks?

The average UK baby at 40 weeks weighs around 3.5 kilograms (7lb 11oz) and measures approximately 51.2cm from crown to heel, though there is a wide range of normal. Your baby's size will have been monitored throughout your pregnancy, and your midwife will have discussed with you if there were any concerns.

What's happening with your baby?

Your baby is fully formed and ready to meet you. Their lungs are mature and ready to breathe air for the first time. Their digestive system is ready to process colostrum and then breast milk or formula. Their nervous system, while not yet fully mature, is developed enough to regulate all essential functions. Your baby may have a full head of hair or may arrive almost bald — both are completely normal. Their eyes may appear to be dark blue or grey at birth, as pigmentation takes several months to fully develop.

If you haven't gone into labour yet

Only around 5% of babies are born on their exact due date, so don't worry if your due date arrives and you're still waiting. Your midwife will offer a membrane sweep at your 40-week appointment (and another at 41 weeks if needed). If you reach 41 to 42 weeks without labour starting, induction of labour will be discussed. Continue to monitor your baby's movements closely and call your maternity unit immediately if movements reduce or change.

What to expect when labour begins

Early labour is characterised by irregular contractions that gradually become more regular, longer, and stronger. A show (passage of the mucus plug) or your waters breaking may precede or accompany contractions. Stay at home in early labour if possible, as this is often the most comfortable and calming environment. Use a TENS machine, warm bath, or the breathing techniques you've practised. Call your maternity unit when contractions are regular and coming every 3–5 minutes, lasting around 45–60 seconds, or sooner if your waters break, you have heavy bleeding, or you're concerned about your baby's movements.

The first hours after birth

After birth, there is a period often called the 'golden hour' in which skin-to-skin contact between you and your baby is encouraged. This has remarkable benefits: it helps regulate your baby's temperature, blood sugar, and breathing; promotes bonding; and stimulates the hormones that support breastfeeding. You may notice your baby instinctively moving towards the breast. Don't rush this time — it's one of the most precious experiences of early parenthood.

In the first hours, your baby will be checked by the midwife and offered vitamin K (an injection or oral drops) to prevent a rare but serious bleeding condition. Your baby will also have their weight, length, and head circumference measured and be given a brief initial health check called the APGAR score at 1 and 5 minutes after birth.

Looking after yourself after birth

The postnatal period — the first six weeks after birth — is a time of significant physical and emotional adjustment. Be gentle with yourself. Accept help from those around you. Sleep whenever your baby sleeps. Eat nutritious food and stay hydrated. Your community midwife will visit you at home in the days after birth, and you'll also have support from your health visitor in the weeks that follow. If you feel persistently low, anxious, or unlike yourself, please speak to your midwife, health visitor, or GP — postnatal depression is common and very treatable.

From all of us at Infatot

Congratulations on reaching the end of your pregnancy journey — and welcome to the beginning of the most rewarding chapter yet. Whether you're already holding your beautiful baby or counting down the last days, we hope this series has been a helpful companion. Wishing you a positive birth experience and a wonderful start to family life.

Frequently asked questions

How many babies are born on their due date?

Only around 5% of babies arrive on their exact due date, so it is very common to still be waiting at 40 weeks. Many babies, particularly first babies, arrive after 40 weeks.

When should I call the maternity unit in labour?

Call when contractions are regular and coming every 3 to 5 minutes, lasting around 45 to 60 seconds — or sooner if your waters break, you have heavy bleeding, or you are concerned about your baby's movements.

What happens if labour hasn't started by 41 weeks?

Your midwife will offer a membrane sweep at your 40-week appointment and another at 41 weeks if needed. If you reach 41 to 42 weeks without labour starting, induction of labour will be discussed.

What is the golden hour after birth?

It is the period after birth when skin-to-skin contact is encouraged. It helps regulate your baby's temperature, blood sugar and breathing, promotes bonding, and stimulates the hormones that support breastfeeding.