Going past your due date and induction of labour

Your due date is an estimate, and going past it is common. ACOG puts the average pregnancy at 280 days, or 40 weeks, counted from the first day of your last period, and NICE says labour usually starts naturally before 42+0 weeks.

An ultrasound scan is often used to confirm the date. Once it’s set, ACOG notes, it doesn’t change, however many scans you have later.

How many labours start after 40 weeks

NICE’s figures show when labours that started on their own began, using dates from the dating scan.

Weeks of pregnancy	Labours that had started on their own by the end of this week
39+0 to 39+6	50.3%
40+0 to 40+6	82.8%
41+0 to 41+6	99.0%

About half had begun by the end of week 39, and almost all by the end of week 41. Induced labours aren’t counted, so the table doesn’t show how many pregnancies past 40 weeks end in an induction.

When induction is offered in the UK, the US and elsewhere

	UK (NHS, NICE)	US (ACOG)	WHO
From 39 weeks	A membrane sweep is discussed at antenatal visits after 39+0 weeks	Induction can be discussed in a healthy first full-term pregnancy with one baby. When you and your baby are healthy, it shouldn’t be done before 39 weeks	Advises against routine induction before 41 weeks in uncomplicated pregnancies
At 41 weeks	Induction is offered if labour hasn’t started	“Late term” runs from 41 weeks up to 42 weeks. Testing and induction may be recommended	Recommends induction once 41 weeks is confirmed
Past 42 weeks	Extra monitoring is offered if you choose to wait	Called “postterm”. Ask your obstetric clinician what they recommend	Not covered separately

NICE asks UK staff to give people with uncomplicated pregnancies every opportunity to go into labour on their own. You can ask for an induction, and NICE says the request should be considered after talking through the benefits and risks for you. In the US, ACOG says research suggests that induction at 39 weeks for healthy women in their first full-term pregnancy may reduce the risk of a caesarean birth (cesarean in the US).

Why induction might be offered earlier

The NHS lists other reasons too:

• your waters breaking more than 24 hours before labour starts, which raises the risk of infection for you and your baby
• a health condition such as diabetes, high blood pressure or intrahepatic cholestasis of pregnancy
• your baby not growing as expected

If your waters break at term, NICE suggests a choice between waiting for up to 24 hours or induction as soon as possible. If they break after 34 weeks but before term, the NHS says you’ll be offered induction or expectant management, where your team keeps checking on you and your baby. In both cases there’s an exception: if you’ve had a positive group B strep test at any time in this pregnancy, NICE says you should be offered induction or a caesarean straight away rather than waiting.

Weighing up waiting against induction

NICE explains that some risks can rise as a pregnancy continues beyond 41+0 weeks, including a caesarean birth, the baby needing neonatal intensive care, and stillbirth and neonatal death.

Its figures, drawn from trials, compare induction at 41 and 42 weeks. About 4 babies per 10,000 would be expected to die with induction at 41 weeks, against about 35 per 10,000 at 42 weeks. For about 9,969 babies in every 10,000, the outcome would be the same either way. NICE says the evidence has limits and shouldn’t be taken as definitive. It also notes that stillbirth rates are higher for women from some minority ethnic backgrounds and those living in deprived areas, who may benefit from closer monitoring.

ACOG puts it the other way round: problems occur in only a small number of pregnancies that go past 42 weeks, and most women who give birth after their due date have uncomplicated labours and healthy babies.

Induction has its own effects. It involves vaginal examinations, and NICE points out that it may limit where you can give birth, because a hormone drip and continuous monitoring aren’t available at home or in midwife-led units. The NHS says you’re more likely to need an assisted birth with forceps or ventouse if you’re induced than if labour starts on its own, and NICE adds that your hospital stay may be longer. Between induction at 41 and 42 weeks, though, NICE found assisted birth was likely to be the same.

How labour is induced

There isn’t one fixed order. What you’re offered depends on your health, your baby and how ready your cervix is, which is checked with a vaginal examination before the first method is chosen. If you’ve had a caesarean before, the methods may differ, so ask your team what applies to you.

Membrane sweep

The NHS says a sweep is usually offered after 39 weeks. Your midwife or doctor sweeps a finger around your cervix during an internal examination, which releases hormones that may start labour. Some women find it uncomfortable or painful, and you may have cramping and some bleeding afterwards. If labour doesn’t start, you may be offered another sweep or an induction.

Hormones

These can go in your vagina as a pessary or gel, or be taken as tablets. You’ll usually be offered hormones first, unless there’s a medical reason you can’t have them.

A balloon or dilator

A small water-filled balloon, or an osmotic dilator (a type of sponge), can be used to widen the cervix.

Breaking your waters and a drip

When the cervix is ready, NICE recommends breaking the waters and a drip of oxytocin, a hormone that causes contractions. You can choose whether to have the drip or delay it, though labour may then take longer and the risk of infection for your baby may rise. ACOG says contractions usually start in about 30 minutes, and you and your baby are monitored throughout.

What it can feel like, and how long it takes

It usually takes many hours for these treatments to start working. You’ll usually stay in the maternity unit, though sometimes you can go home and come back.

Induced labour is usually more painful than labour that starts on its own. Being induced doesn’t restrict your pain relief, and the usual options, such as an epidural, should be open to you. NICE notes there may be limits on using a birthing pool, so ask your unit.

Induction doesn’t always work. If labour doesn’t start, the NHS says you may be offered another method, a caesarean, or a wait of a few hours before being checked again. ACOG says that if labour doesn’t progress and you and your baby are doing well, you may be sent home and can book another attempt.

Going ahead, waiting or changing your mind

Whether to be induced is your choice. NICE says you can go ahead with, delay, decline or stop an induction, that your decision should be respected even if staff disagree, and that you should have time to think it over.

If you decide to wait past 42 weeks, you should be offered more monitoring. NICE says this might mean heart-rate monitoring twice a week and an ultrasound to check the fluid around your baby. Monitoring gives a snapshot of how your baby is now and can’t reliably predict what comes next. You can revisit your decision at every appointment.

You’ll probably hear tips for bringing labour on yourself. The NHS says none are proven, and herbal supplements could harm you or your baby.

Questions to take to your appointment

• Why is induction being offered to me, and when?
• What would happen if I waited, and how would my baby be checked?
• Which method would you start with, and why?
• Which pain relief, including a birthing pool, can I use if I’m induced?

When to call while you wait

During the wait, or partway through an induction, call your midwife or maternity unit straight away in the UK if your baby’s movements slow down or change. ACOG says to go to hospital if your waters have broken and you aren’t having contractions, you’re bleeding heavily from the vagina, you have constant, severe pain with no relief between contractions, or your baby is moving less often.

If you’ve gone home during an induction, NICE also advises calling when contractions begin, if nothing has happened in the agreed time, if your waters break, or if you have bleeding. Call too if you have a lot of pain, contractions that feel too strong or too frequent, side effects, or the pessary falls out.

Heavy bleeding needs help straight away. The NHS says to call 999 if you’re pregnant and bleeding and the bleeding is heavy (soaking a period pad soon after putting it on), or you have severe pain in your tummy, or you feel faint or dizzy.