Pregnancy Week 40: Your Due Date — What Happens Next

11 min read

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 offered if labour has not started naturally by 41 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.

Average weight	Around 3.5kg (7lb 11oz)
Average length	About 51.2cm crown to heel
Born on due date	Around 5% of babies
Induction offered	If labour has not started by 41 weeks
Call maternity unit	Regular contractions every 5 minutes or more often

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's 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 do not go into labour naturally by 41 weeks, you'll be offered induction of labour. 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 midwife or maternity unit for guidance if you think you're in labour, or your contractions are regular and coming every 5 minutes or more often. Call them immediately if your waters break, you have vaginal bleeding, or your baby is moving less than usual. Call 999 if the bleeding is heavy (soaking a period pad soon after putting it on), or you think your baby is coming now and you have a strong urge to push.

When to get help

Some symptoms in pregnancy can be a sign of something serious and need checking quickly. This is who to contact, and how soon.

Call 999 if:

you're bleeding from your vagina and the bleeding is heavy (soaking a period pad soon after putting it on), or you also have severe pain in your tummy, pain in your shoulder, or feel sick, faint, dizzy or lose consciousness
you think your baby is coming now and you have a strong urge to push (ask for an ambulance)
you have severe difficulty breathing (you're gasping, choking or not able to get words out) or your chest feels tight or heavy
you have pain and swelling in one leg and you also feel short of breath or have chest pain. A blood clot in the leg can travel to your lungs, which can be life-threatening
you have possible signs of sepsis, such as breathing very fast, being confused or having slurred speech, blue, pale or blotchy skin, a rash that does not fade when you press it, or a very high or very low temperature. Being pregnant makes sepsis more likely
you do not feel you can keep yourself safe (a mental health emergency is as serious as a physical one)

Always call 999 if you think it's a life-threatening emergency, no matter what stage of pregnancy you are.

Call your midwife or maternity unit now if:

your baby is moving less than usual, you cannot feel your baby moving anymore, or there is a change to your baby's usual pattern of movements
you have light bleeding or spotting, even if you have no pain or only mild tummy pain
you have stomach pain that is severe or does not go away after you've rested for 30 to 60 minutes, or stomach pain with regular cramping or tightenings, lower back pain, or pain when you pee
you're less than 37 weeks pregnant and you have a gush or trickle of fluid from your vagina (this could be your waters breaking), regular contractions or tightenings, period-type pains, or backache that's not usual for you
your waters break, even if labour has not started
you have signs of pre-eclampsia: a severe headache that does not go away with simple painkillers, vision problems (such as blurred vision or seeing flashing lights), pain below the ribs, sudden swelling of the face, hands or feet, feeling very unwell, heartburn that does not go away with heartburn medicines, or being sick (vomiting)
your skin is very itchy (for example, it keeps you awake at night), the palms of your hands or soles of your feet are itchy, or the itching is worse at night. This can be a sign of a liver condition called intrahepatic cholestasis of pregnancy (ICP) that needs urgent treatment
your breathlessness comes on suddenly, you're out of breath when you're lying down, or you're breathless and also have chest pain or feel dizzy
you have pain or swelling in one leg, usually in the calf or thigh. This could be a blood clot (deep vein thrombosis, or DVT), which is more likely when you're pregnant
you have a high temperature (38C or above), or you feel hotter than usual or shivery. A high temperature can be a sign of an infection, so it's important to get it checked
any of your contractions last longer than 2 minutes, or you're having 6 or more contractions every 10 minutes

If your baby's movements change, do not wait until the next day: call immediately, even if it's the middle of the night. Do not use a home doppler to check the heartbeat yourself. Even if you hear a heartbeat, this does not mean your baby is well.

If your waters break, use a period pad (not a tampon) so your midwife can check the colour of the waters, and tell them immediately if the waters are smelly or coloured.

Call your midwife or maternity unit for guidance if you think you're in labour, or you're having regular contractions coming every 5 minutes or more often.

You can also call your midwife or maternity unit if you're unsure or worried about anything.

If you cannot reach them, or you're not sure what to do, call NHS 111.

Speak to your midwife or GP if:

you're worried about your mental health, or stress, anxiety or low mood are affecting your day-to-day life. If you need urgent help for your mental health, call 111 and select the mental health option, or ask for an urgent GP appointment

Go to sleep on your side. From 28 weeks, the safest position to go to sleep is on your side, either left or right. Research suggests that, after 28 weeks, falling asleep on your back can double the risk of stillbirth. This includes daytime naps. If you wake up on your back, just turn onto your side and go back to sleep.

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. Tell your midwife, health visitor or GP straight away if you have sudden or very heavy bleeding from your vagina (you may feel faint or have a rapid heartbeat), pain, swelling or redness in the calf of one leg, a high temperature with a sore, tender tummy, a headache with changes in your vision or vomiting, or difficulty breathing. Call 999 or go to A&E if you have chest pain or severe difficulty breathing, as this could be a blood clot in your lungs. 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. If you need urgent help for your mental health, call NHS 111 and select the mental health option, or ask for an urgent GP appointment. Call 999 or go to A&E if you do not feel you can keep yourself or your baby safe.

From all of us at Infatot

Congratulations on reaching the end of your pregnancy, 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 your midwife or maternity unit for guidance if you think you're in labour, or your contractions are regular and coming every 5 minutes or more often. Call them immediately if your waters break, you have vaginal bleeding, or your baby is moving less than usual. Call 999 if the bleeding is heavy (soaking a period pad soon after putting it on), or you think your baby is coming now and you have a strong urge to push.

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 don't go into labour naturally by 41 weeks, you'll be offered induction of labour.

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.

Sources & further reading

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.