Induction of Labour - Part 1

Updated: Nov 8, 2020

More than a third of Australian women today have their labours induced. As this method of intervention becomes more and more common, it’s important that we understand exactly what an induction is, why its recommended and what the risks are that come with being induced. As I say in most of my episodes, being informed and educated well in advance will mean that if this is something that ends up being recommended or brought up at some point near the end of your pregnancy, you don’t feel completely in the dark and at the mercy of health professionals, but instead, you feel equipped and prepared to understand your options and make decisions about your care more confidently.

This topic is pretty dense so I’ve broken it up into two parts.

Here’s this week’s content (in short – always better to listen to get all the information)

What is an induction of labour?

An induction is an intervention that happens to stimulate the start of labour. There are a number of different ways that this can be done, and sometimes multiple steps will be taken to finally initiate labour.

‘Medical’ options for induction mean that medications such as synthetic prostaglandins or oxytocin are required whereas a ‘surgical/mechanical’ methods of induction may be the artificial rupture of membranes, or a balloon catheter. Once it is determined or recommended that you have an IOL most often a midwife or doctor will perform a vaginal examination (VE) to determine what steps will be required to get this labour going. The VE is looking to see if the cervix is soft and stretchy, but most importantly, whether it is open at all. If it is open and the bag of waters which the baby is floating around in can be reached (1-2cm+ dilated), this means that medical methods of induction may not be required initially, and that breaking the bag of waters would be the first step needed. Whereas if your cervix is closed, obviously the health care provider wouldn’t be able to break the bag of waters, so some sort of process to soften and open the cervix would be required – which could involve both medical and surgical methods.

It’s worth unpacking each of the possible methods of induction because you may end up needing one, or a number of these during your last few days or hours of pregnancy. I’ll explain them in the kind of order that a lot of hospitals will conduct them in, from the very first steps for women who have a long, closed cervix, to then the last methods which are for women whose cervix is already opening.

- Prostin gel – this is a gel made up of a synthetic prostaglandin (a hormone that prepares the body for labour). It is placed at the top of your vagina, behind/underneath the cervix with the idea that it will soften or ‘ripen’ the cervix. Before the gel is inserted the baby will be monitored by a CTG (cardiotocograph) to make sure baby sounds happy and well and then the midwife or doctor will insert the gel the same way we’d do a VE. The baby then needs to be monitored again for about half an hour or so while the mum continues to lie in a semi-recumbent position (making sure the gel doesn’t just fall out). The monitoring after the gel insertion is important to make sure the baby and your body isn’t responding badly to the gel.

Sometimes a second dose of gel is required (especially common for first time mums) and it is usually inserted 6 or 12 hours after the first dose. Again, this is done via another VE which will determine that maybe the cervix is still closed and hasn’t softened enough, so the second dose is inserted. If at this stage the cervix feels soft and is opening, the second dose may not be required and the next step in the induction process can begin.

- Cervidil – This is another way of applying synthetic prostaglandin to the cervix. It looks a bit different to the gel and resembles a kind of flat tampon with a string that hangs out of the vagina. The strip at the end is placed behind the cervix and it releases the prostaglandin. Just like with the gel, a CTG is attended before inserting the Cervidil and after to make sure baby remains well. If there are any issues like the baby not responding well or some other things which I’ll cover in part 2, the string can be pulled to remove the Cervidil. With both prostaglandin induction methods, the mother remains in the hospital to have regular monitoring every couple of hours. Often its just by preference of hospital or doctor that they might prefer one way or the other (gel or cervidil) but there are also some risk factors that mean that one of these two options is preferred over the other.

- Balloon Catheter – This is another method used to ‘ripen’ a cervix. It’s generally offered if the hormonal (prostaglandin) options haven’t made enough changes to the cervix and the bag of waters around the baby is not able to be felt to be broken, it becomes the next step. This method of induction may also be used for women who have risk factors that mean use of the prostaglandin is contraindicated, for example a previous caesarean section who is wanting a vaginal birth. The cervix still needs to be ‘ripened’ in order to access the bag of waters.

How it works is that a woman in positioned in stirrups and a speculum is inserted inside the vagina (like getting a PAP smear), and a thin plastic catheter/tube is inserted through the hole in the cervix. Two small balloons are then inflated with water on either side of the cervix – one on the inside of the uterus where the baby’s head and bag of waters are and one on the other side – inside the vagina. The pressure of these two balloons squeezes the cervix which hopefully mechanically softens and opens it up a bit. The catheter tends to stay inside for about 12 hours or until it has fallen out. If it does fall out that’s a great sign that your cervix has opened as that top balloon has come from inside the bottom of the uterus, through the cervix to then fall out of the vagina. With the catheter, again the baby needs to be monitored before it's inserted and after its inserted, and fairly regularly whilst the catheter remains inside.

All three of these methods of ripening the cervix have the potential to start labour so women remain inpatients at the hospital during these processes (at least in the hospitals I’ve worked at). Sometimes little niggles will start with each of these options and Panadol or Panedeine Forte can be taken, but unless labour has really kicked off these niggles are generally pretty manageable. These methods of induction are also most likely to take place in either an antenatal ward or the postnatal/maternity ward of a hospital where women are able to rest. Only when labour really kicks off and is established or plans have been made to attend the next steps of an induction - then the woman will be transferred into the birthing suite.

So hopefully one of these three methods has successfully softened and opened the cervix slightly, if it hasn’t put you into labour, then the next step in the induction process can take place. At this stage normally an Intravenous Cannula will be inserted in your hand or arm which will be the access for the synthetic hormone that brings on labour. You are then moved across to the birthing suite where the plan is that baby will be born basically that day – as the team are taking steps to make labour happen.

The next step would be:

- ARM (Artificial Rupture of Membranes) – If your waters have not yet broken than an ARM will likely be recommended. How this happens is that your doctor or midwife will attend another VE where they will scratch a little hole in the bag of waters around the baby’s presenting part. Its normally done with a little hook which the mother and baby don’t feel at all, it’s just like bursting a water balloon. Of course, this can only be done if the cervix is open enough to get a finger or two through it to touch the bag of waters. Again, with this process the baby is monitored by CTG to ensure bub remains happy. Once your waters are broken sometimes contractions just start naturally but if not, the next step in the induction process begins. Depending on the risk factors to baby and mum and the reason for induction, you may be given four hours or so to stand up and move around and hopefully encourage contractions to start on their own, but depending on your case, the doctors may be recommending the next step straight away.

- Oxytocin – if you’ve heard a number of my previous episodes I’ve spoken about the hormone oxytocin and its work causing contractions of the uterus. So, what happens next in the induction process is that a synthetic version of oxytocin (often called Syntocinon or in America it’s known as Pitocin) is given via the IV cannula as an infusion to stimulate contractions of the uterus. It starts off at a really slow/small rate and gradually is turned up with the intention to mimic labour and in order to try and ensure the baby remains happy as contractions build up. (Don’t want to just go full steam ahead cos the baby will be like what the hecks going on). The infusion continues to be increased (granted the baby is happy) until the woman is having strong, regular contractions that we’d consider are effective in opening the cervix and bringing the baby down (eg. 4 or 5 contractions every ten minutes that last about 60 seconds). The infusion continues to run at that rate then generally until after the baby is born (some places do trial turning it off to see if the woman’s body continues contracting on its own now that it’s started, but I haven’t really seen this happen much). If an oxytocin infusion is running the baby needs to be continuously monitored by CTG and I’ll explain the risks and reasons for this in a bit.

Another thing to point out with this method of induction is that it could actually be the only step needed for some women – maybe their waters broke but contractions never naturally started so there’s a risk of infection and this is where stimulating contractions to begin by Syntocinon is recommended. Other women whose cervix is already starting to soften and dilate may only need the ARM or the ARM plus oxytocin infusion to get things going without any cervical ripening needed – so as you can gather there are a range of ways that induction may actually play out.

If you’re eager to hear an example of an induction of labour experience, Mum Will Know listener Tolly Macrae generously shares the birth story of her third child, where she was induced at 40 weeks for preeclampsia. It’s a great way to see how some of these methods of induction worked together to put Tolly into labour when the risks of preeclampsia meant continuing with the pregnancy could be potentially risky.

Thanks so much to Tolly for sharing a little about her IOL experience. I’ll delve into some of the reason’s inductions are recommended in Part 2 next week and as I do that you’ll hear a little more about preeclampsia. Just to finish off this episode I thought it would be interesting to find out what the prevalence of IOL in Australia is…

Just from working in this birth space I feel like there’s definitely a fair chunk of women who are induced whether that’s for medical reasons or not – and I’ll get into that in part 2… But, in terms of how common an IOL is in Australia? From what I can find – there’s a 2015 ‘Mothers and Babies’ report by the Australian Institute of Health and Welfare which basically gives an overview of the statistics collected from each state and territory around things like antenatal care, maternal health, place of birth, onset of birth & method of birth, and a whole lot of information about babies as well… And from this 2015 report it was found that a third of Australian women had their labours induced and this was an increase compared to the same statistics gathered back in 2005.

The other statistic I found that was a little closer to today’s date, was that of women aged between 20-34 having a single baby in the head down position, in which this was their first baby… and these statistics are from 2017 across Australia – which found that 43% of these women had their labour induced. So, there’s definitely a significant number of Australian women who experience one or more of these methods to establish labour.

I hope by reading/hearing about these steps you can be equipped and prepared for what may be something that comes up for you in the future. Sometimes it is, like in Tolly’s experience a bit of a shock and you don’t get much time to think through what’s going on, so having this information way in advance can really help you feel less in the dark if it is something that’s recommended later down the track.

As always, I’d always recommend actually listening in to the episode to really get all the information and you don’t want to miss Tolly’s birth story.

If you want to connect with me, find me on both Instagram and Facebook @Mumwillknow.

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To read more on IOL and see where I found some of this information, check out these resources:

Labour induction for late-term or post-term pregnancy (2016)

QLD Clinical Guidelines: IOL

WHO recommendations for Induction of Labour

Induction of labour indications and timing: A systematic analysis of clinical guidelines (2019)

The Royal Australian and New Zealand College of obstetrics and Gynaecologists – Induction of Labour

Mothers and Babies report (2015)

Australian Institute of Health and Welfare National Maternity Data Development Project: Indications of induction of labour (2016)

Australian Institute of Health and Welfare National Core Maternity Indicators: Induction of Labour (2019)

Photo by @alygraphs