Induction of Labour
This information is to help you understand the care and treatment that you will receive during your induction of labour.
What is induction of labour?
Labour is a natural process that normally starts on its own but sometimes it is advised to be started artificially. This is called induction of labour and can take several days until your baby arrives.
Why has induction of labour been offered to me?
There are many reasons why you may have been offered an induction of labour. Broadly speaking the reason this being offered is because it may be better or safer for you and/ or your baby, to be born sooner. Our priority is the continued wellbeing and safety of you and your baby. The decision to induce labour is never taken lightly without discussing it fully with you. Induction of labour is a different process to spontaneous labour, and the process is explained further down.
Common reasons include:
- prolonged pregnancy over 41 weeks
- labour does not start after waters have broken
- concerns about the growth of your baby
- medical problems such as diabetes
- pregnancy problems such as high blood pressure
What should I bring with me?
It is difficult to predict how long your stay in hospital is likely to be. We suggest you bring your hospital bag, toiletries, books, or magazines. Please do not bring valuables into hospital with you and should only bring in a car seat when you are due to be discharged.
Risks and benefits
- Induction of labour, when compared to waiting for spontaneous labour in lower risk pregnancies, does not significantly increase the risk of an emergency caesarean birth.
- Induction of labour can increase the chance of instrumental delivery (ventouse or forceps) and a tear involving the anal sphincter (this is known as OASI, obstetric anal sphincter injury. The OASI care bundle will also be offered to you to try and reduce this risk).
- There appears to be no difference in other outcomes for the mother, except that there is a lower risk of developing blood pressure problems by being induced rather than waiting. If there have been other complications in your pregnancy, then having the baby sooner may be safer for you.
- For the baby, overall, induction of labour is safe. Usually, part of the reason it is being offered is, so the baby is born sooner and so reducing the risk of stillbirth.
- If a baby is born before 39 weeks there is a small increased risk (an extra 1 in 1000) that baby may need admission to the neonatal unit, so inductions before 39 weeks are performed when there is more concern with waiting. However, the actual process of induction does not seem to increase the risk of complications for the baby or mother.
- In lower risk pregnancies we offer induction to all pregnant people from 41 weeks. This is because the risk of stillbirth increases most quickly after 42 weeks. The risk of stillbirth at 42 weeks is 1 in 1000 births and increases up to 3 in 1000 if the pregnancy continues up to 44 weeks gestation.
Some other risks associated with different aspects of the induction of labour process are detailed in the rest of this leaflet.
How is natural labour encouraged?
Before you are offered induction, you may be offered a membrane sweep as this is recommended by the National Institute of Clinical Excellence (NICE, 2022). A “sweep” has been shown to increase the number of people who go into labour naturally in the following 48 hours after it is performed. It takes only a few minutes. A membrane sweep involves a vaginal examination performed by your midwife or doctor, during which a finger is inserted just inside the cervix (neck of the womb) and circular, sweeping movements are made to separate the membranes that surround the baby. This stimulates the cervix to release labour inducing hormones which are naturally produced by the body called prostaglandins. Some pregnant people may still find this painful and afterwards there may be some period type pains. It is very common to notice some blood staining or a “show” especially on wiping or after passing urine. This is not harmful and should settle after a few hours.
After the examination you will be able to continue your usual daily activities. Some pregnant people have more than one “sweep.”
In the event of any fresh red blood loss after your appointment, please contact Maternity Triage.
What happens on the day the induction starts?
Once orientated to the ward, some routine checks will be performed on you and your baby, including:
- Checking your temperature, pulse, urine, and blood pressure.
- Examining your abdomen to check the size and position of the baby and how low baby’s head is in the pelvis.
- Monitoring the baby’s heart rate with a CTG machine.
Your midwife or doctor will make sure you understand the plan of care and answer any questions or concerns you may have.
How is labour started?
There are several methods that can be used to start labour. If the cervix is ready for labour (assessed by internal examination of the cervix) it may be possible to break the waters around the baby (artificial rupture of the membranes, ARM).
The internal examination of the cervix will tell us the position of the cervix, how long the cervix is, how soft the cervix is and whether the cervix is open.
If breaking the waters is not possible because the cervix is not ready for labour then we have two main methods to induce the labour:
- Non-hormonal/mechanical dilator (Dilapan-S, cervical ripening balloon).
- Hormonal treatment (Propess and Prostin tablets).
What does induction with Dilapan-S® involve?
Dilapan-S is a synthetic rod that absorbs fluid and expands. Usually 3-4 rods are placed inside the cervix during a speculum or vaginal examination and over 12-24 hours they expand and dilate/soften the cervix gradually.
After this time they are removed and a repeat vaginal examination is performed and most of the time (in over 90%) we find we are now able to break the waters. The waters can be broken once there is a midwife on delivery suite available to continue your care.
At busy times there can be delays waiting for your waters to be broken. If delays occur, you will be kept up to date and you and your baby will continue to be monitored. The insertion takes around 5-10 minutes, and can be uncomfortable, but most patients tolerate it well. Minor bleeding can occur afterwards, but this is not a concern.
You will be asked to lie down after their insertion for 20-30 minutes, but after this you can move around and go about daily activities normally (with the exception that having a bath is not recommended). While the Dilapan-S rods are in place most patients are not aware of them, and they do not usually cause contractions so there is not usually any pain.
You should let the midwife know if you think the rods are falling out.
What does an induction with a Cervical Ripening Balloon involve?
A cervical ripening balloon is when a catheter (plastic tube) is passed through your cervix, (a plastic device called a speculum will be used in order to see your cervix) and the small balloon is inflated with 30mls of water so it sits between the bag of waters and the base of your womb. This will hopefully encourage your body to release their own prostaglandins to soften and open your cervix and as the cervix opens it may help oxytocin to be released to create contractions.
This method of induction can be used as an alternative to Dilapan-S. It is a good option if you have had a caesarean birth before where there is an increased chance of your scar separating or if there are concerns that your baby is very small and would be more likely to be stressed if hyperstimulation occurred (creating too many contractions with prostaglandins).
What does an induction with Propess® or Prostin involve?
Prostaglandins are naturally occurring hormones released by the body in normal labour and also after a membrane sweep. The aim of the pessary or tablets (synthetic prostaglandin) is to soften and open the cervix, so the waters are able to be broken.
A Propess pessary or Prostin tablets are inserted into the vagina during examination. Once in place, they sit behind the cervix and slowly releases prostaglandins that cause the cervix to soften and the womb to contract.
Propess is a bit like a tampon and has a tape so that it can be easily removed whereas Prostin tablets dissolve at the top of the vagina.
Propess is removed either once labour starts at the end of the treatment time (24 hours) or earlier if required. After the pessary or tablets are inserted, you will be advised to stay on the bed for half an hour, then you will be encouraged to mobilise as this helps stimulate active labour. Take care after washing and going to the toilet to not dislodge the pessary. You can remain dressed and eat and drink as normal.
Sometimes you will be aware of period type pains which are less intense than contractions. These may build up to proper labour pains or fade away as the effect of the medication wears off. If you are feeling uncomfortable, discuss with your midwife what pain relief you would like. There is a range of options even in the very early stages of labour including gentle mobilisation, lying in a warm bath, pain relieving tablets or a TENS machine (if you have one).
Occasionally, Propess or Prostin can cause hyperstimulation in up to one in every ten people who receive this medication. This is when contractions occur too frequently or last too long and can occasionally cause stress to the baby. This is detected by monitoring baby’s heartbeat on the monitor and may result in medication being recommended to slow down the contractions or in some cases an emergency caesarean birth.
Other possible side effects of Propess or Prostin are nausea or vomiting, diarrhoea, increase in temperature, lowering of blood pressure, increased need for pain relief and vaginal soreness/dryness which can make future vaginal examinations uncomfortable.
During this time the midwife will review you regularly by:
- Checking your temperature, pulse and blood pressure
- Asking about any pain or vaginal loss
- Asking about your wishes for pain relief
- Listening to your baby’s heartbeat, this may involve being continuously monitored for a time
Please inform your midwife if you have any vaginal bleeding, think your waters have broken or feel unwell in any way.
What is the difference between Dilapan-S and Propess/Prostin tablets?
Usually both of these methods are available for you to choose. However, in some cases one method might be recommended as safer for you and your baby.
The main differences are:
- Dilapan-S does not usually cause contractions, it mechanically dilates the cervix. This means it might be safer if you have had a caesarean before, if you have had more than two children before or if your baby is small and we are more concerned about the impact of contractions on the heartbeat. Dilapan-S does not therefore cause hyperstimulation.
- Dilapan-S tends to cause less pain during the induction as it causes less contractions.
- Dilapan-S seems to have a more reliable effect. On one hand this means we are more likely to be able to break your waters after 12-24 hours of its use when compared to Propess/Prostin. However, because it does not usually cause contractions it won’t start off labour, which can sometimes occur with Propess/Prostin. This means you are more likely to be advised to have synthetic oxytocin through a drip to help with the contractions (this is the case in around 95% of inductions with Dilapan-S, and 70% with Propess).
Overall, from when the induction of labour is started to when you have the baby the time is similar whichever is used first.
How the baby is born is similar whichever is used first (i.e. there are similar rates of emergency caesarean birth.)
What happens if the Dilapan-S (or Cervical Ripening Balloon) or Propess doesn’t work?
After one course of treatment with Dilapan-S we are unable to break the waters in around one out of ten women. With Propess we are unable to break the waters in three out of ten. If this is the case then you would be offered a repeat treatment (a second cycle) with the same agent or a different agent. Other options that you can choose include resting for a period of time before trying again or having a caesarean birth.
What does breaking the waters involve?
If a vaginal examination is performed and your cervix has started to open and the membranes surrounding baby can be felt then we should be able to break your waters. This is also referred to as artificial rupture of membranes (ARM).
Prior to breaking your waters we would monitor baby’s heart rate for around 20 minutes or longer if required. The procedure begins as a vaginal examination to assess the cervix, and during the procedure a long plastic device is inserted alongside the examining finger. This device has a specially designed tip which makes a hole in the membranes surrounding the baby and releases the fluid inside the womb. The midwife will check the fluid is clear and listen to baby’s heartbeat.
Once the waters are broken and baby’s head descends onto the cervix, some people may start to feel period type pains which may increase in intensity and continue to become contractions.
The risks associated with having an ARM include:
- cord prolapse (if baby’s head isn’t engaged well into the pelvis there is a chance that the baby’s cord can slip past the baby’s head and into the vagina. If this happens it is an emergency and requires immediate delivery of baby)
- a scratch to baby’s head (sometimes if the amniotic sac is tightly against baby’s head there is a possibility that baby’s head may have a little scratch on it from the tip of the plastic device).
What is a Syntocinon® drip?
If after breaking the waters your labour doesn’t begin, you will be advised to have a drip called Syntocinon (which contains oxytocin) to start contractions. This is an artificial version of the hormone produced by the body that normally generates contractions. The drip is gradually increased until you are having regular contractions, 3-4 in every 10 minutes, and progressing in labour. The baby’s heart rate is recommended to be continuously monitored while on the drip.
Very occasionally Syntocinon can make your womb contract too frequently which may affect your baby’s heart rate. If this happens the drip will be adjusted or stopped for a while to allow contractions to slow down.
Very rarely, if the baby’s heart rate is affected and doesn’t return to normal, a caesarean birth may be required. For this reason, once the drip is in place, you will be on Delivery Suite where you can be monitored closely. If this is your first pregnancy it is recommended that Syntocinon is commenced as soon as we have broken your waters as it is often a lengthy process. If you have had a baby before it is recommended that if labour hasn’t started between two to four hours after your waters have been broken, the Syntocinon drip is started.
However, if you have any concerns or questions about this, please speak to your midwife.
Other risks associated with the Syntocinon drip include:
- a higher chance of bleeding excessively after the baby is born (the oxytocin receptors can become desensitised and react more slowly to further Syntocinon so additional medications may be necessary to help the muscles in the womb clamp down on the blood vessels)
- an increased need for pain relief (contractions caused by the Syntocinon drip can feel stronger and last longer).
- Syntocinon can cause you to ‘hold on’ to any water you drink or any fluids you receive during labour. This can result in swelling, usually in your hands, ankles and feet.
How long will my induction take?
The induction process can vary a lot from person to person ranging from a few hours to a few days (if the cervix is not ready for labour and you require more than one cycle). Once the process has started, however, we aim to continue the induction until your baby is born.
At times when the Delivery Suite is very busy and there are no labour rooms or available midwives, it would be unsafe to continue, and a delay may occur in the induction process. On these occasions, the senior clinicians give priority to those people in established labour. Please be assured that the induction process will re-commence as soon as possible, and the midwife/doctor will keep you updated.
You will be monitored closely on the ward and transferred to Delivery Suite when a room becomes available. Should a delay occur, we apologise in advance and thank you for your patience.
If at any time you wish to stop the induction of labour process you can speak to your doctor or midwife about alternative options.
What if my waters have already gone?
Sometimes, your waters may break on their own. In this case you have a choice between trying to start the labour off straight away, or waiting for labour to start naturally, if you are well, and the fluid is clear.
If you want it to be started straight away, we will commence the Syntocinon drip in order to start the contractions. Labour will start naturally within 24 hours in around 60% of people, but if it does not, we would recommend starting the Syntocinon drip after 24 hours. This is to reduce the risk of serious infection to the baby which doubles to 1% after waters have ruptured for over 24 hours.
What if I do not want you to start my labour?
You will be given information about induction of labour, and why this has been recommended for you, but it will then be your choice as to whether you want to go ahead with the induction.
If you decide not to be induced following discussion with your doctor or midwife this will be respected, and we can arrange an opportunity for you to discuss your options with a specialist midwife. We may also advise additional monitoring for you and your baby depending on your individual circumstances. If the induction has been offered because of going overdue this additional monitoring (such as a scan or heart rate monitoring of the baby) would usually start at 42 weeks of pregnancy.
This additional monitoring can provide some reassurance that your baby is growing normally, and the placental function is normal, but it is important to note that this additional monitoring can be falsely reassuring and should not be relied upon.
Some risks associated with a pregnancy continuing beyond 41 weeks may increase over time. These risks include an increased risk of fetal distress in labour leading to an increased likelihood of a caesarean birth, an increased likelihood of baby needing admission to the neonatal unit and an increased likelihood of stillbirth and neonatal death. (NICE 2022)