Episode 74 - The Cascade of Interventions
[0:00] Welcome to the Great Birth Rebellion podcast. I'm your host,
[0:03] Dr. Melanie Jackson. I'm a clinical and research midwife with my PhD. And each episode, I cast a critical eye over current maternity care practice by grappling with research and historical knowledge to help you get the best out of your pregnancy, birth and postpartum journey. The back story is that i think last week i said to everybody i've just been at a birth and today i've just been at a birth too like for the midwife i know i'm really in it guys you can really feel confident that i'm not just speaking in an ivory tower i'm actually on the ground in the trenches caring for women it's all happening i'll have a nap after this all right Welcome everybody to
[0:52] this week's episode of The Great Birth Rebellion.
[0:55] Today we're talking about a concept that has previously been a bit hard to prove and we're still actually in the process of proving it.
[1:06] It's been knocking around for a long time. Certainly I heard it before I was a midwife and I've seen it written in literature in the 60s and 70s. I don't know who coined the term. I want to know the origin of that term, the cascade of intervention, because it's become, you know, just something we all as midwives go, oh yeah, yeah, the cascade. And some knowing women know about the cascade of intervention. And that's what we're talking about today is the cascade of intervention. And I love that phrase. It's such a visual way of describing what can happen when you interfere with birth physiology. And so that's the concept we're talking about today. we're going to work through this in detail and the cascade of intervention is linked to the medicalization of childbirth globally. Today I really want to focus on the cascade of intervention realizing that it's very easy to slip into conversations about medicalization but we're going to leave that over there for a second and come back to it. Today we need to focus on the cascade i want to also talk about the nuance of it so we're going to consider the cascade of intervention but also just kind of nibble at the sides of the idea of the cascade of interference and the cascade of omittance i'm calling it that's that's me i've never heard everyone say anyone say the cascade of omittance.
[2:33] The cascade of omittance is what I'm calling, it's not providing something that women need in order for their labour and birth to progress physiologically. And just considering if the cascade of omittance is part of the cascade of intervention or the cascade of interference. So what does it mean? Let me see. The cascade describes the need for more intervention to remedy the impact of the previous intervention. That's a nutshell definition. I'll say it again for people who are like, what did she say? The cascade of intervention describes the need for more intervention to remedy the impact of the previous intervention.
[3:17] If we backtrack a little bit, if we describe what an intervention is, because I want to just really focus on the fact also that interventions are not all bad, but we have to acknowledge that they're not all good either Because some people believe that everything you do to intervene in labour and birth makes it better and safer and more successful and that it couldn't possibly introduce more risk or more danger or a side effect into your birth process. And that's not true that's what the cascade of intervention is is acknowledging that while some interventions can improve birth outcomes we have to acknowledge that they can also make outcomes worse sometimes you'll have an intervention and it works exactly as it was intended and there was no side effect and sometimes it doesn't do any of what you're expecting it to do and only gives you more problems. This is what we're grappling with, I suppose.
[4:21] Well, let's talk about necessary versus unnecessary because this is the next stage in the conversation. So our purposes for today, we're going to focus on interventions during pregnancy, labor and birth because there are interventions that are routinely applied during postpartum and that are routinely applied to babies. But today, our examples and focus are going to come from the time of pregnancy, labor and birth.
[4:46] So in our context, an intervention is the process of interfering with or acting to alter the course or outcome of a woman's pregnancy, labor and birth process. So the interventions can either have a positive effect and result in correcting the course of labor and birth that's gone wrong, or they can be counterproductive and actually cause pathology in the process. They can either be necessary or unnecessary interventions.
[5:16] Unnecessary interventions are often seen as what we would call routine. So interventions can either be routine where it's, I call it birth by numbers. You know, like if you get a painting set and they go put the green here, put that green number eight here, put blue number seven here, it's paint by numbers. Routine interventions are like birth by numbers. So when you go into hospital, midwives have this mental checklist in their head. Okay, this woman's walked in. I need to find her a room, put a CTG on, do a VE, whatever the tick list is. So it's birth by numbers. That's what we would consider routine intervention. Something that just you routinely get when you walk into a hospital. And they can either be that or they're done in response to an event or a circumstance that's occurring and whoever's looking after you feels that it's a necessity that you have this intervention in light of what they're seeing. And people's feelings about how necessary interventions are, are rooted in their philosophy of childbirth. Some people believe that without any intervention or supervision in your birth, without a health professional there, without clinical skills, there's no way your birth could go well.
[6:36] Other people sit at the complete other end of the spectrum, believing that if you have somebody there who can clinically intervene, your birth is more likely to go wrong. Where you see necessity of intervention is deeply rooted into your philosophy around childbirth. So if you trust that childbirth is physiological and will mostly go well without intervention, then you're going to assume that most intervention is unnecessary. The other end of the spectrum is if you believe that birth is a medical event and therefore needs management, you're going to assume that you need every single intervention that's coming your way in order to stay safe. So if we're looking at interventions and we're thinking about the routine ones, they're usually the ones that are not clinically indicated. So there's nothing, there's no emergency, there's nothing gone wrong at the moment. This is just policy and procedure. This is what everybody gets regardless of circumstance. And sometimes these are your screening things like a vaginal exam. That's, it's, it's a screening tool and it's performed with a purpose of trying to find or identify a problem or diagnose something that's not currently obvious. All of a sudden you're doing routine interventions to try and screen and find problems. This kicks off the cascade.
[7:56] And those interventions are the ones that women often talk about as being unnecessary. Like I wasn't in any danger. No one was in danger. We were just doing them to find a problem and to diagnose and screen.
[8:09] Then there's the emergency and clinically indicated interventions. And these are the ones that are performed once there's a problem that's been identified. So we're using an intervention to try and diagnose, understand or reverse or resolve a problem. For example, so I'm a home birth midwife. We don't do routine vaginal examinations. In hospital, you're likely to get them every two to four hours, depending on your circumstance as a routine practice.
[8:36] But I was with a client a little while ago who had a very long labor and we were getting to the point, you know, almost 30 odd hours in where everyone, including the woman, was wondering what was going on. And we all agreed together that we thought a vaginal exam would be appropriate at this time because we were in an unusual circumstance she felt things weren't progressing I noticed things weren't progressing she was feeling stuck and tired and we thought right we need to understand what's happening here and then it was discovered that the baby was not in a position where it would be able to come out at home.
[9:17] So when we got to hospital, a manual rotation was done and the baby came out. This was what we all deemed a necessary intervention that when applied had the ideal outcome. So often in emergencies, women have agreed that those were a necessary intervention and the benefits outweigh the risk. Whereas I think with routine interventions, it's not clear if the benefits outweigh the risk of doing that intervention. So I think when you're trying to work out, is this an intervention that I want and that I think is necessary? You can try and weigh up, does the risk of this outweigh the benefit? Would it be better for me to have this? Or is it likely to expose me to more risk than benefits?
[10:07] In those circumstances, women say to themselves, I don't want this, but I know I need it. So with that woman who we transferred that had the manual rotation, she's like, I don't want to go to hospital, but I know that I need to go to hospital. She was walking herself out the door. This wasn't the plan. And so she had all these things and the outcome was good. And she's like, you know, I would have preferred to stay at home,
[10:33] but I absolutely did need to go. And the previous 73 episodes of the great birth rebellion are about trying to help you guys work out which interventions you think are necessary and which interventions you are not necessary and that's actually unique to every single individual birth so we can't tell you what is an unnecessary intervention except to say that they're usually the routine ones and when you're not in actual danger. If you want to get a better understanding of what is a routine and what's a necessary intervention, you've got to listen to episode one to 73. One of the studies I looked up, which I will touch on as we go, looked at interventions over a 20-year period and how much they changed and how they're not linked to an improve in outcomes and actually discussed that the cascade of intervention.
[11:31] As interventions increase in number, they're also exponentially increasing in number because then you have to factor in the addition of the cascade. It can be anything that triggers the cascade that basically leads to another intervention that requires another intervention that requires another one in order to remedy the impact of the initial intervention. I want to further define the cascade, but as I was researching this, it occurred to me that we are looking at this whole idea of the cascade of intervention through incredibly privileged eyes and within a context that has.
[12:13] High access to quality medical care. So here in Australia where we are and most Western countries, we have the problem of too much intervention and too many resources when other countries, they have a problem of not enough intervention and all resources. And so like both extremes are problematic. I think it's two problems. I think some countries have a problem where they don't have enough access to interventions and that causes poor outcomes and ill health. The other extreme, which is the problem that we're addressing here today, is the abundance extreme, where we use interventions simply because we have them without always considering if they're absolutely necessary. So there are people listening today who wished that they had had access to an intervention, but they didn't because of their location or lack of resources or systematic failures or decision-making at the time didn't allow for it. So we realised that the rejection of the opportunity for intervention comes from a position of absolute privilege. And what we're talking about today, it just fails to speak to the experience of countries where they have poor access to medical help in childbirth and where it's lacking. Something that happens when you either have not enough intervention or too much intervention, it starts to have a consequence on the well-being of women and babies. And so our problem is that our interventions, and this is not me saying it.
[13:42] I will be talking about a paper later that is questioning the concept that interventions are always done for the good of the woman and the baby because, The question now is, is that is all this intervention we're doing actually counterintuitive and creating harm? And so that's the discussion we want to have. We know that the vast majority of birth will go well without interference. However, if we're to truly understand birth, we've got to understand that there are absolutely times when physiology does not work the way that it should.
[14:19] Physiology fails. It's a hallmark of humanness, of bodies that are not perfect, that our bodies sometimes don't work and that interventions can and do have a role in that to help correct physiology that's turned into pathology. The trick is finding the balance. The skill and trick in this is that you have a clinician who you can work in partnership with to decide, do we need to intervene? Which interventions would you be willing to have? Do you feel like you need them? And together are making those decisions because every intervention has the desired result, has a desired result and an undesired result that you can't just have all good or all bad. So it's weighing up the risks and benefits and deciding if it's worth it. So the cascade of intervention denotes the concept that when you perform an intervention that you can alter the course of a labor and birth. And if the birth is unfolding physiologically and then an intervention is done as a routine thing, this can throw off the delicate flow of labor and introduce pathology into a labor process that was not currently pathological. And it can cause events to cascade into pathology. And this is medically caused. It's what we call an iatrogenic consequence, a medically induced consequence.
[15:48] Alternatively, if the birth is unfolding pathologically and an intervention is performed, it can redirect the labor into a physiological path. So that example I gave before where we transferred in, manual rotation was performed and the doctor said to the woman, push out your baby. So the doctor did the intervention of manual rotation. The woman's body was still contracting and she pushed out her baby there was it was a minimal minimal intervention maximal impact like that altered the course of her pathological labor return it to a physiological path but that's not always the case and that's where the cascade of intervention is mostly noticed, I mean, some examples of the cascade, there are countless, when I was a student, I went on a little journey on paper, a paper journey, and I thought, I am going to make a map of the cascade of intervention, like a flow chart, like if this, then this, you know, yes, did that happen? No, did that happen? Those kinds of things.
[17:00] It's impossible to map that kind of thing. But research has linked certain interventions to other interventions. And something that I've seen happen, for example, if someone ruptures your membranes, breaks your waters, and causes a cord prolapse, which leads to an emergency cesarean section, so something I've witnessed occur when I was a student, that is an immediate clear cascade. If that midwife hadn't broken those waters, the cord wouldn't have prolapsed at that time. She wouldn't have needed a cesarean section. and similar like epidural for example an epidural can cause a baby to turn into a posterior position.
[17:40] Increasing the need for manual rotation or forceps or vacuum or possibly leading to a cesarean section or I've also witnessed an epidural where a woman's been having a really long labor has had an epidural managed to have a sleep relax her body and mind had a snack and then dilated and progressed in labor like I've seen that before too so you just can't predict it but what we need to recognize is that there's short and long-term cascades so a short-term cascade could be I've had an epidural so now I need an augmentation to get my labor going again or if you lengthen out that cascade so I had an epidural which did lead to a posterior baby which led to the need for a cesarean section, you've then pushed out the cascade all the way through to your next birth as well, where now you're feeling the impact of that initial cascade on your next pregnancy. This is a long-term cascade.
[18:43] They just push the risk and the cascade up the chain for women. So the Australian Institute of Health and Welfare report that the most common reason for a caesarean in Australia is a history of previous caesarean section. So 86% of mothers who had a previous caesarean section are having a repeat caesarean in their subsequent birth. That's a cascade of intervention. So every caesarean that a woman has increases her risk of something going wrong in that next birth and in subsequent pregnancies. So it's not just in that moment.
[19:19] So there was a great study done here in Australia by Fox et al. In 2021, where they looked at almost 100,000 women who gave birth over a three-year period in Queensland public hospitals. And they wanted to make kind of this diagram that I was just talking about as a student. They wanted to make a chart to examine the factors that were contributing to the two top clinical conditions that led to cesarean section for women in Queensland. And the two things that, the main two things that were leading to cesarean section are a fetal heart rate anomaly, so abnormal fetal heart rate, and what they call inadequate contraction. So that usually means either a long labor or the labor pattern isn't what they were predicting or expecting it should be to lead to adequate progress towards birth. So this could be the term, I hate the term and we're going to do a whole episode on it, but failure to progress where you're having a slow labor. Yeah, those were the two major reasons that women were having cesareans. Among the sample of women who had a cesarean section, 41% of them who had the cesarean section experienced fetal heart rate abnormality. So abnormal fetal heart rate was the reason for cesarean in 41% of women.
[20:40] But then the study asked, but what was the reason for the abnormal fetal heart rate? And the authors had a look at the sample where abnormal fetal heart rate was present. And 39% of those mothers had their membranes ruptured artificially. So their waters were broken by a midwife with a hook or a doctor. So of the 41% of women who had cesarean sections for fetal heart rate problems, 39% of them their waters artificially ruptured and only 20% of the mothers did not have their membranes artificially ruptured. So you could almost double the chance of fetal heart rate problems if your membranes are artificially ruptured, which can then lead to the need for cesarean section. So now we see a correlation between artificial rupture of membranes leading to abnormal heart rate, which led to cesarean section, which was more so in women who didn't have their membranes ruptured. So that was the first tracking that they did with this study of 100,000 women. So now another thing they noticed was that among women who had oxytocin for induction or augmentation of labor with artificial oxytocin, so syntocin on all pitocin, 32% of those women experienced fetal heart rate changes compared to 17% in mothers who didn't have oxytocin.
[22:09] So now they notice that augmentation and induction increase the chance of abnormal heart rate and therefore led to those primary caesareans. So this is the cascade at play, is they've been able to track that there's an increased risk of caesarean section and an increased risk of the causes of those caesarean sections when you do things like artificially rupture a woman's membranes or initiate the use of artificial oxytocin for induction or augmentation. Then they also looked at epidurals and 52% of women with an epidural who had a cesarean section had their cesarean section because they had an abnormal fetal heart rate compared with 38% of mothers who did not have an epidural. So this study is saying that if one of the main reasons for primary cesarean section is abnormal fetal heart rate. And what are some of the main causes of abnormal fetal heart rate?
[23:08] It's labor interventions such as epidurals, artificial rupture of membranes, and the use of artificial oxytation to speed up labor. Then they looked at this sample of women who had inadequate, I'm using inverted commas, inadequate contractions. Inadequate contractions were associated with 33% of women who had had an epidural compared to only 10% of women who didn't have an epidural. So now what they're noticing is that you're almost or you're over, you're three times more likely to have inadequate contractions if you have an epidural and inadequate contractions. Again, using inverted commas when I say inadequate contractions because it's horrendous language.
[23:55] Inadequate contractions was one of the main reasons for cesarean section. So now they're linking epidural to a reduction in uterine action to the need for cesarean section. So this paper in 2021, it was a big paper and it brings together what clinicians have already been noticing about interventions. But there was another recent paper, 2021, by Rydell, and they state that current labour practices have seen an acceleration in interventions to either initiate, monitor, accelerate, or terminate the physiological process of pregnancy and childbirth. And the number of interventions increased during their study period, so they looked at interventions over a 20-year period.
[24:48] They not only increased, they noticed the increase in the use of intervention, but the increase in the number of interventions that each woman needed, in inverted commas. As interventions, they interfere with the physiological process of labour and they carry potential risk of short and long-term consequences. And the findings in this paper call for what they said, careful re-evaluation
[25:12] of contemporary maternity care with a first do no harm perspective. So now we've got researchers suggesting that to actually give unnecessary routine interventions is harmful and against the moral and ethical ethos of medicine.
[25:31] The complexity is that the interventions start becoming necessary because the cascade is kicked off. If you have an intervention that leads to a complication...
[25:43] You have to remedy that complication. And so the rest of the interventions become necessary. But we've got to be super careful because this is the distinction between medically indicated intervention and unnecessary routine intervention. By no means are we suggesting that you decline emergency interventions.
[26:04] Like interventions are there for when things don't go well. But consider if you need an intervention if things if nobody is in danger if you've listened to this podcast today and gone do you know what actually I'm cool with the possibility that I might be exposed to the cascade of intervention because I do want an epidural and so I'm willing to accept the increased risk that it might cause distress in my baby that it might cause a posterior position that might then require manual rotation or and then you might go you know what now that I know that that's possible I'm still willing to accept this intervention so I think that's also the idea of today is to make you realize that there is the possibility of the cascade and then it's up to you to answer whether or not you're willing to take the risks of that versus the benefits. So if you need an epidural or you need an augmentation or an induction or a vaginal exam or you want to have your waters broken, that's fine.
[27:12] It's just about knowing that there could be other outcomes other than the one you were expecting. If you're in that camp where you're thinking, right, I do not want to accept unnecessary intervention. I want to protect myself from the possibility of a cascade of intervention. We actually have some beautiful research papers that give women direct information about how you can keep yourself safe from unnecessary intervention and put yourself in a situation where you might only need to accept very necessary intervention. And some of the strategies that the research is talking about is they've suggested using intermittent auscultation of the fetal heart rate instead of CTG as a way to keep yourself safe from a cascade. So that means using a Doppler instead of continuous monitoring.
[28:05] Favoring non-pharmacological labor and pain control intervention so we had a whole episode on managing labor without medicine which you could go back to and the other ones that can reduce your risk of being exposed to the cascade are having one-to-one support during labor so that could be a doula the robust friend that we spoke about last week your own actual care provider your own midwife that's looking after you these are things that are shown to keep you safe from unnecessary intervention think about it if you want less intervention you've got to go for a less interventionist model of care and that's usually with midwives and that's usually as far away from a tertiary hospital as you can get in terms of either having it at a birth center or at home and.
[28:58] The further along you go into so public hospitals are typically less interventionist than a private hospital that's very generalized statement but if you look statistically you know considering declining routine interventions that are not being applied because you or your baby are actual danger so you determining for yourself does this feel routine something that everybody would get part of birth by numbers and labor care by numbers or am I and my baby in actual tangible danger and is something actually going wrong that needs to be corrected there's another reason why people might be encouraging intervention in a time sensitive manner and that is constraints of the system the system constraints I mean and it's again it's not about necessity, but it kind of also is because you're at the mercy of the location and of the care providers. So nutshell, cascade of intervention exists.
[30:04] You can either choose to keep yourself safe from that by making decisions about which interventions you believe are necessary and which are not, or accept the possibility that you'll be wrapped up in the cascade of intervention and be okay with that when you choose to accept interventions. So we're not saying don't take interventions. We're just letting you know that the cascade is a possibility and now it's up to you to gauge what you want to do with that information that's the cascade of intervention ladies and gentlemen to get access to the resources for each podcast episode join the mailing list at melaniethemidwife.com and to support the work of this podcast wear the rebellion in the form of clothing and other merch at thegreatbirthrebellion.com. Follow me, Mel, @MelanietheMidwife on socials and the show @TheGreatBirthRebellion. All the details are in the show notes.
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