Episode 7: Induction of Labour
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Episode 7 Content and Overview
In episode 7 of the Pregnancy and Childbirth podcast, Dr Greg, obstetrician and gynaecologist, discusses induction of labour.
Induction of labour involves using medical treatment to artificially stimulate the commencement of labour.
Labour induction may be recommended when your pregnancy care provider feels that it is in the best interest of either you or your baby for birth to be brought on sooner, rather than waiting for labour to begin naturally.
When considering labour induction, it is important to be aware of the benefits and risk so that you can decide what is best for you and your baby.
Listen to the podcast to have your questions answered:
What is induction of labour?
Why do we induce labour?
What are the risks?
When shouldn’t we do an induction of labour?
How do we induce labour?
What are the myths around induction of labour?
If you've reached a point in your pregnancy where you're having a discussion around induction of labour with your pregnancy care provider, there are three important questions that should be addressed:
Why are we doing an induction of labour? Part of that why question should involve a balancing of the risks and benefits
When will we induce labour? Are we going do an induction of labour just after 39 weeks, or are we going to wait until 41 to 41+ weeks?
How will we induce labour?
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Transcription
0:00
Hi, I'm Dr. Greg, obstetrician, and welcome to this episode of my pregnancy podcast. Today, we're going to talk about induction of labour.
0:11
Induction of labour, also known as induction, or IOL, is one of the commonest interventions performed in the latter part of pregnancy. Recent studies suggest that as many as 40%, and in some hospitals, perhaps even more than 40% of women will undergo induction of labour in the latter part of their pregnancy.
0:31
The frequency of induction of labour has increased in recent years. And we'll come to some of the reasons for that a little bit later. So why don't we start with defining what it is we're talking about. So what is induction of labour? Induction is when we make a decision to artificially stimulate the commencement of labour. And we'll talk about some of the ways that we do this a little bit later as well.
0:58
So why do we do induction of labour? And why has it become more common? Induction of labor is done either for the benefit of the mother, or for the benefit of the baby, or perhaps a combination of the two. Essentially, the decision that we're making is that we feel it would be in the best interest of either mother or baby, for the pregnancy to come to an end and the baby to be born, rather than for the pregnancy to continue.
1:26
So what are some of the common reasons where we might perform an induction of labour? It might be considered because the pregnancy has continued for a bit too long. We used to think that it was perfectly reasonable to allow pregnancies to continue to 42 weeks and beyond. We now know that once we go beyond 41, to 41 and a bit weeks, the risks to the baby, even in what appears to be a low risk pregnancy, do start to increase a little bit as we move closer to 42 weeks. So most people would now agree that induction of labor is a reasonable thing to consider.
2:03
Once we get to the 41 to 41 and a half week stage of pregnancy, there are other reasons for considering an induction of labour other than being overdue. For example, if we feel that your baby is not growing well, in the latter part of pregnancy, we might consider that it's a little bit safer to deliver the baby rather than to allow the baby to remain in the uterus.
2:26
There are other medical conditions such as pregnancy diabetes, and high blood pressure or preeclampsia, which are also some of the common medical reasons while we might have a discussion around induction of labour. And there's an increasing amount of evidence to suggest that if your baby appears to be very large, that induction of labour a little bit before the due date, probably results in a greater likelihood of a good outcome for you and your baby, compared with allowing the pregnancy to go beyond the due date.
3:01
Sometimes induction of labour is performed for reasons of maternal preference. For example, there can sometimes be a lot of discomfort associated with the latter part of pregnancy. And for some women having their baby just prior to the due date rather than having to endure another week of pregnancy can be highly preferable. Sometimes for matters of convenience, organisation of work, organisation of childminding, and various other activities of daily life can be more easily planned, if there's a scheduled date for delivery of the baby. So maternal preference can certainly come into the equation when making decisions around induction of labour.
3:45
Now, there's one other factor which we need to talk about in any discussion around induction of labour. And that's the risk of stillbirth. There's an initiative launched in Australia in the last 12 months called the safer baby bundle, which is about implementing measures to try and reduce the rate or the likelihood of stillbirth in the latter part of pregnancy. Whilst this is not a common occurrence, all of us would agree that any initiatives that can be undertaken to help reduce this tragic occurrence would be worthwhile. So part of the initiatives in the safer baby bundle is to think carefully about each woman's pregnancy and to think about the risk factors that may exist for the risk of stillbirth as we approach the due date.
4:39
And whilst we don't always understand the exact reasons for stillbirth in the later part of pregnancy, we are aware of some of the risk factors that increase the likelihood of this tragic occurrence. By identifying women with risk factors and discussing these risk factors. We can come to a plan for the timing and safe delivery of your baby. I should reiterate that the likelihood of stillbirth occurring in the latter part of pregnancy is very low and Australia does have one of the lower rates of near term stillbirth of most of the developed countries in the world.
5:21
So when shouldn't we do an induction of labour? Well, again, there was another initiative launched a few years ago by New South Wales Health, called every week counts. And this highlighted the fact that if baby's healthy and well inside the uterus, that there are a lot of very important developmental things that occur for your baby up to 39 weeks gestation. So unless there's a very clear medical indication for delivery prior to 39 weeks, a strong preference for the benefit of your baby is to keep baby inside your uterus until at least 39 weeks gestation.
6:03
Well, what do we know about induction of labour? We know that if we induce labour after 39 weeks gestation, that there doesn't seem to be any increased risk to mother or baby of having a bad outcome because of the induction of labour. We also know that induction of labour from 39 weeks on does not appear to be associated with an increase in likelihood of having a caesarean birth and we can be reasonably reassured about the reliability of this information based on a very large trial that was conducted and published within the last couple of years. It's called the arrive trial and it showed quite clearly, that induction of labour from 39 weeks on was not associated with any harms for either mother or baby.
6:55
Now, that doesn't mean that induction of labour is completely risk free. We do know that induction of labour is an artificial way of commencing labour. And we know that when we induce labour, or move from a situation where there are essentially no uterine contractions, to a situation where there are very frequent and painful, strong uterine contractions, and this transition happens much more quickly with an induction of labour than happens for women whose labour starts naturally. So with naturally occurring labour, there are often several hours of pre-labour where the contractions will be fairly spaced out and fairly mild, and will gradually progress to those more frequent, strong and regular contractions. And that certainly happens much more quickly in the presence of an induction of labour. Now for some women, this can make the contractions seem much more painful, and seem more difficult to cope with. So whilst not everybody who has an induction of labour has an epidural, if we look at epidural rates amongst women who are induced, they are a little higher compared with women whose labour has started spontaneously.
8:14
Having an epidural is not necessarily a problem. But if you've had an opportunity to have a listen to my podcast on epidurals, and I'll give it a plug if you hadn't, it's well worth a listen, you would know that whilst epidurals are safe, there is an increased likelihood of having either a vacuum or forceps assisted birth, if you have an epidural compared with women who labour without having an epidural.
8:41
Now, because we're using drugs to artificially stimulate the uterine contractions, there is a need for continuous fetal monitoring or CTG monitoring during labour. Whereas if you had a naturally occurring labour and you didn't have an epidural or oxytocic drugs to stimulate your uterine contractions during labour, you wouldn't necessarily need to have continuous fetal monitoring. And this can make mobilising and labour a little more difficult if you're connected to a monitor. You can still mobilise and be active in labour with a monitor, but it is one of those things that does tend to get in the way a little bit.
9:21
The other thing about using oxytocin drugs to stimulate uterine contractions, we are a little more likely to have abnormalities of your baby's heart rate during labour. This occurs a bit more often in induce labour's compared with naturally occurring labour's provided we manage this carefully during the labour, it doesn't seem to result in an increase of the need for a caesarean birth, or an increase in the likelihood of your baby becoming compromised during labour.
9:55
I guess that brings us to some of the commonly held myths around induction of labour. So as we've already said, induction of labour is not associated with an increased likelihood of a caesarean birth. Induction of labour is not dangerous for the health or well-being of your baby. It's commonly said that induction of labour is more painful than naturally occurring labour and we've addressed the reasons why that may be the case. It's often said that if you have an induction, you'll have an epidural. And that certainly doesn't need to be the case. I've cared for many, many women who've had induction of labour and not had an epidural. But epidurals are more likely in women who have an induction of labour compared with those that don't.
10:46
So what about the issue of induction of labour purely for reasons of maternal request? Well, as we've heard, if we're looking at induction of labour, anytime from 39 weeks on, this is not associated with any harm for either mother or baby. So I think we should be open to the idea of having an informed discussion with the women we look after, so that they're in the best position to make a decision about whether induction of labour electively after 39 weeks is something that they feel comfortable with. And if they do, the preference of the pregnant woman, and or her partner should be respected.
11:27
Well, what if you want to avoid having an induction of labour? Is there anything that you can do to help bring on the labour naturally? There isn't a lot of good quality evidence or information to guide us in this area. One thing that has been shown to be beneficial is a vaginal examination involving a strip and stretch, or a sweep of the membranes. This involves your pregnancy care provider, doing a gentle internal examination and if your cervix is a little bit dilated already, as it often is, after 39 weeks gestation, it's possible to give the cervix a gentle stretch, or to sweep the membranes away from the inside of the cervix. It's thought that this stimulates release of natural prostaglandin, which is a hormone released by your cervix, the membranes and the lining of the uterus. And prostaglandins are thought to play an important role in the initiation of labour. So this examination can be a little uncomfortable but there is some evidence that there's an increased likelihood of labour occurring within a few days of this examination, compared with women who have not been examined.
12:40
If you Google natural methods for induction of labour, you'll come up with a long list of suggestions for things like castor oil, which will probably just give you a nasty case of diarrhea, spicy food, exercise, sexual intercourse, nipple stimulation, herbal remedies, such as raspberry leaf tea, and also acupuncture. Now, it's not to say that none of these things are going to cause initiation of labour in some women. But the available evidence we have does not support any of these things being effective in initiation of labour. So not to say you shouldn't try them but you should be aware that there really isn't any evidence to show that they work.
13:27
If you've reached a point in your pregnancy where you're having a discussion around induction of labour with your pregnancy care provider, there are three important questions that should be addressed and which you should have an answer to. The first is why you're doing an induction of labour and part of that why question should involve a balancing of the risks and benefits. So the risks of continuing with the pregnancy, compared with the risks of doing an induction of labour, versus the benefits of doing an induction and the benefits of continuing with the pregnancy. And the decision, by and large should be based around a balancing of those risks and benefits.
14:07
The second question is when, so timing of induction of labour is critical, are we going do an induction of labour just after 39 weeks, or are we going to wait until 41 to 41+ weeks? Obviously, the longer we wait, the greater the likelihood that your labour will occur spontaneously in the meantime.
14:26
And the final question should be the how. What methods are going to be used to induce your labour? How is this going to occur? We've already spoken a little bit about risks and benefits, and we've spoken a bit about timing. So let's move on to the how are we going to do an induction of labour. So before having an induction of labour, you will need to have a vaginal examination to assess your cervix. And we rate your cervix as either being favourable or unfavourable. And this means how ready is your cervix for the onset of labour.
15:03
Now, if your cervix is not very ready for labour or unfavourable, then we will usually recommend some cervical ripening techniques. So these are techniques to help get your cervix ready for labour. So there might be two steps in doing an induction of labour for you if your cervix is not ready. The first step will be about getting your cervix ready for labour and the second step will be actually getting you into labour. Now, if your cervix is already ripe, in other words, if it's ready for labour, you don't need to do the first step so it's going to be just about getting you into labour.
15:40
So what if your cervix is not ripe or not ready for labour, then how will we approach this? So generally, you'll come into hospital the day prior to the induction and depending on which methods are used, you might stay in hospital overnight prior to your induction, or you might be able to go home and come back the following day.
16:02
Fundamentally, there are two techniques for preparing your cervix for labour. The first is what's called a balloon catheter. So this is a rubber or latex tube, which is inserted through your cervix with an examination a little bit like a pap smear, and the balloon is blown up on the inside of your cervix. The balloon is about as big as a 50 cent piece approximately when fully inflated. The examination to put the balloon in is usually quite well tolerated. It's a little uncomfortable. Most women tolerate this really well. The balloon causes some irritation to your cervix and to the membranes, and causes release of natural prostaglandins and as we mentioned earlier, prostaglandins play an important role in not only in the initiation of labour, but also in the ripening of the cervix. And the benefit in using a balloon is that there's quite a low likelihood of you coming into labour from this technique. It doesn't stimulate uterine contractions, so it's very safe for your baby and therefore, if you've had a balloon inserted, it is safe for you to go home and come back the following morning for your labour to be induced.
17:15
The second technique is to use a vaginal medication called prostaglandin and this can be either administered as a gel or as a vaginal tablet. Before insertion of either the gel tablet or balloon catheter, you will have a fetal monitoring or a CTG carried out and you'll have another monitoring following the procedure.
17:39
Now, if you're having gel or vaginal prostaglandin tablet, you will need to remain in hospital overnight, because these medications can cause uterine contractions, and some women, although it's not the intent of the medication, some women will come into labour in the few hours following the administration of this medication. So some additional fetal monitoring is required if you've been given prostaglandin medication vaginally. The aim of both of these approaches is that by the following morning, your cervix will be more ready for labour than it was before and this will make initiation of your labour easier and make the induction more effective.
18:22
So hopefully by the following day, your cervix will now be a little bit more dilated, perhaps two to three centimeters dilated, and the next step in initiating labour will be most likely to break your water. So doing a vaginal examination, and using an instrument a little bit like a crochet hook to break the waters in front of baby's head. This is a little uncomfortable, but it's a very safe thing to do. And then we initiate the uterine contractions, so the labour contractions, with a medication called oxytocin. And this is just like the hormone that your body releases to sustain labour. And this is given as an intravenous infusion, so it's given through a drip. Now once you're on the oxytocin infusion, we started at a low rate and we increase it gradually, and it will be necessary to continuously monitor your baby's heart rate through the duration of labour. If we commence oxytocin, it'll usually be necessary to continue that medication right through until the end of the labour.
19:23
Now, if your cervix was ripe or ready for labour, you don't need the vaginal medication or the balloon catheter. And you're most likely just come in to the birth unit on the morning of your induction to have the waters broken, which is an artificial rupture of membranes or ARM, and commencement of the oxytocin infusion through a drip. Sometimes if your cervix is very favourable, meaning it's very ready for labour, and if the baby's head is sitting quite low, it's possible that we could commence an induction just by breaking your waters and allowing you to hop up and mobilise and walk around, and that might be enough to initiate the onset of labour.
20:04
However, once we've broken your waters, there's no going back from that point. So if your labour contractions don't come on in the next couple of hours, we will be committed to needing to put in a drip and commence an oxytocin infusion. Although in that setting is light that only a very small amount of oxytocin will be required to initiate the onset of the labour contractions.
20:26
That covers off most of the things I was wanting to say about induction of labour. So just to reiterate, the advice contained here is of a very general nature and I think it's really important that if induction of labour is something that's been suggested, or something that you're contemplating, then it's really important that you have an individualised discussion with your pregnancy care provider. And I think, thinking about those questions around induction of labour, so why am I having an induction, or why am I requesting an induction, and what are the risks and benefits associated with that decision? And if we're doing an induction, how do we think about the timing, so choosing the right time in pregnancy is critical to making sure that it's a good decision to go ahead with an induction and then finally having a good plan in place for exactly how your induction is going to be carried out. I think if you've got all of that information, then you're in the best possible position to make a good decision for both yourself and for your baby.
21:32
So hopefully, you found that information interesting and informative. As always, we will be very interested to receive any feedback or suggestions for future episodes and bye for now.
