Most women don't expect to need an induction. But because around a third of women in the UK have one, it is important to understand what an induction of labour is before having to make that decision.
This guide details what to expect when having an induction of labour, and answers the questions I hear most often working as an NHS midwife.
What is an induction of labour?
An induction of labour means that your labour is being started artificially (rather than waiting for your body to go into spontaneous labour), in order to deliver your baby sooner.
An induction of labour involves a number of steps, which this guide will explain later.
Why might an induction of labour be needed?
There are lots of reasons why an induction of labour might be recommended. Some of these include:
- You have gone past your due date
- Your waters have broken but your labour has not started
- You have a suspected infection in your womb
- You have high blood pressure or pre-eclampsia
- You have diabetes
- Your baby is particularly big or particularly small
- Certain maternal medical or obstetric conditions
However, this is not an exhaustive list, and you may be offered an induction of labour for other reasons.
... top tip
Being offered an induction of labour does not mean that you have to accept it. Always make sure you understand 1) why it is being offered, 2) what the risks and benefits are, and 3) are there any alternatives to an induction of labour.
What happens during an induction of labour?
An induction of labour often happens in stages, and different methods may be used depending on how ready the cervix already is.
Membrane sweep
A membrane sweep is not considered a formal method of induction – rather it makes spontaneous labour more likely, and so may help to reduce the need for formal induction of labour.
A membrane sweep involves a vaginal examination during which the midwife tries gently to separate the membranes from the cervix using a finger. This may release natural prostaglandins, which may encourage labour to begin naturally.
If your cervix is completely closed, the midwife will not be able to perform a membrane sweep.
It is common to experience some cramping, spotting or irregular contractions after a membrane sweep.
Formal induction of labour
... midwife's insight
Most inductions are started on the antenatal ward in your maternity unit. Sometimes, women are able to have an 'outpatient induction' which means they go home for a period of time having started the induction in hospital. Other inductions are started on the labour ward. Where you are for your induction depends on your clinical situation as well as your preferences.
Prostaglandins
During a formal induction of labour, the first step is to dilate your cervix to the point where your waters can be broken. This first step tends to be done on the antenatal ward, but it may also be on the labour ward if you are considered particularly 'high risk'.
Whilst every hospital will have a slightly different regime, the most common way this is done is by giving prostaglandins. Prostaglandins are chemical messengers which help the cervix to prepare for labour, by making it soft, thin and start to open. Prostaglandins can be given in the form of a tablet, gel or pessary, and are usually given vaginally.
Sometimes rods or a balloon may also be used to help dilate your cervix (this is more likely if you are having an induction of labour and have previously had a caesarean section).
Precisely what is used for this first step in the induction process will depend on your hospital, as well as your individual clinical situation.
Artificial rupture of membranes
Once you have dilated enough that your waters can be broken you will be transferred to the labour ward where your waters will be broken (called an artificial rupture of membranes).
Your midwife will use an amnihook (which looks a bit like a crochet hook) to break your waters whilst doing a vaginal examination.
Sometimes, breaking the waters is enough to start strong contractions (because your baby's head is now applied directly onto your cervix without the cushioning bag of waters in front of it).
Some hospitals will give you 2 – 4 hours from breaking your waters to see if you do start contracting spontaneously before advising the oxytocin hormone drip. Other hospitals will advise starting the hormone drip straight away after breaking your waters – it depends on your hospital's policy, your clinical situation and your preferences.
Oxytocin hormone drip
This is a synthetic form of the hormone oxytocin, which is the contracting hormone. It is given via a cannula and the dose is gradually increased until your contractions are strong and regular and coming generally 3 – 4 times in every 10 minutes.
... midwife's insight
Remember that any of these steps may be missed out if you do not need them. Before starting an induction, your midwife or doctor will usually assess your cervix with a vaginal examination. This is called a Bishop score and helps determine which method of induction is most suitable.
For example, sometimes women come into hospital for their induction of labour, and the midwife finds on examination that it is possible to break their waters without them receiving any prostaglandins.
How long does an induction of labour take?
There is often no predicting how long an induction of labour will take. For some women the process is quite quick, and for other women it can take a number of days.
Even during induction, you remain part of the decision-making process throughout. You can always ask questions, ask for time to think and discuss alternatives as you go.
What are the risks and benefits of an induction of labour?
Benefits
Induction of labour should only be recommended by the doctors if it is safer than continuing the pregnancy for you or your baby. It doesn't mean that the doctors think your pregnancy is suddenly dangerous, rather that at a certain point or in certain situations, the balance of risk gradually shifts so that delivering your baby is thought to be safer than continuing the pregnancy.
Therefore the main benefit of an induction of labour is to reduce the risks associated with continuing the pregnancy when there are reasons why it may be safer for you or your baby to be born sooner.
Risks
It is difficult to be precise about the risks of an induction of labour, because the risks will depend partly on why you are being induced, and how many of the induction steps outlined above you need.
Generally speaking, an induction of labour:
- Can be a long process – sometimes with many days spent in hospital before baby is born
- Can lead to more intervention (frequent vaginal examinations, continuous CTG monitoring and an oxytocin infusion)
- Can cause uterine hyperstimulation, where contractions become too frequent or prolonged. This can affect your baby's heart rate and may mean that treatment is needed to reduce the contractions.
- Can increase the risk of epidural analgesia, assisted vaginal birth or caesarean section, but this risk does depend on your individual circumstances
Some of these interventions are more common with induction than in spontaneous labour.
... midwife's insight
Induced labour can feel more intense or painful than spontaneous labour. Contractions caused by an oxytocin drip can become strong and regular relatively quickly, rather than building gradually as they often do in spontaneous labour.
Everyone experiences labour differently, but it is worth thinking about your pain relief options before your induction begins. You should still have access to the usual range of pain relief options, including an epidural if you want one and it is clinically appropriate.
Depending on the method of induction and your individual circumstances, you may need to give birth on an obstetric-led labour ward rather than in a midwife-led unit. This is because some methods of induction, particularly an oxytocin infusion, require continuous CTG monitoring and access to obstetric care.
Can I decline an induction of labour?
An induction of labour is your choice. You can accept, decline or ask for more time to consider your options.
If you choose to decline an induction of labour which has been advised, you will have a discussion with your doctor, and your pregnancy will be managed according to your individual circumstances, taking into account your preferences.
What happens if the induction of labour doesn't work?
If your labour does not establish or progress despite the induction process, you may be offered further attempts, a period of waiting and reassessment, or a caesarean birth depending on your circumstances and preferences.
A note from the labour ward
Induction of labour can take time, sometimes much longer than women expect, particularly if your cervix is not yet ready (or 'favourable') for labour.
You may spend hours, or even a couple of days waiting for the next step. This can be frustrating, especially when you are excited to meet your baby and may see other women arriving and giving birth before you.
Don't be afraid to ask questions, rest when you can, and remember that you remain part of the decision-making process throughout an induction of labour.