Episode 114 - Is CTG ever beneficial?
Mel:
[0:00] Welcome to the Great Birth Rebellion podcast. I'm your host, 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.
Mel:
[0:24] Welcome to today's episode of the Great Birth Rebellion podcast. Today, I've invited Dr. Kirsten Small again for the third time who is a career academic retired obstetrician and an industry expert in the use of CTG fetal heart rate monitoring. Kirsten's PhD was on this topic of CTG and she's the mistress and owner of birthsmalltalk.com where she offers free evidence-based information about the use and misuse of CTG monitoring. Kirsten's been here for the last two episodes and we've spoken about the use of ctg in pregnancy labor and birth but today we're specifically talking about if ctg use is ever helpful because i know it seems like all we keep saying is no don't use it it doesn't work because there's no research but today we'll look at the evidence about when maybe it could be of some benefit kirsten thank you for lending your expertise to us yet again to talk about ctg you're welcome we got there all right so what i thought i would do is i would go through various lists of scenarios that women are offered ctgs and we can basically go through yes or no beneficial or not should we be using those scenarios and as we have that discussion, we'll discover if there are any actual scenarios where the use of a CTG might actually be beneficial.
Kirsten:
[1:53] Sounds great.
Mel:
[1:54] Sounds great. All right. So the admission CTG when presenting in labour, and for people who have not yet had a baby, when you turn up to hospital in labour, often the very first thing that they will do for you is put you on a CTG so that they can put you in the, oh, no, something might be wrong category or the, hey, you were fine when you arrived category. gory. So Kirsten, admission CTGs, yes, no, maybe?
Kirsten:
[2:26] So the idea behind them is that they're done for women who are considered low risk on the basis that if you're considered high risk, you'll be recommended continuous CTG monitoring. So you don't need an admission CTG, you need, she says with scare quotes, ongoing CTG monitoring. This is designed to try and identify a subset of women who appear to be low risk, but where the foetus is actually at risk in a way that will be detected by the admission CTG. And the women that are then identified as now having a foetus at risk will then be offered continuous CTG monitoring in labour.
Kirsten:
[3:13] The really interesting thing I find about this particular set of research is that of the collections of research that we talked about, the antenatal stuff a couple of podcasts ago, and that was all done in the 1980s. The in-labor stuff starts in 1976, finishes in 2006. Most of it was done in the 1980s. When it comes to the admission CTGs, it's done in the noughties. So from 2001 to 2008, with one more recent one since then. So it's quite late in the piece. And by the time we're doing this research, we already have a large body of evidence that says that continuous use of a CTG in labour doesn't improve outcomes. So now what we're doing is research to go, if we just add a few more people into the list of people that we do continuous fetal monitoring for, will that improve outcomes? So it's a great example of the shining optimism that people have that CTG monitoring actually works if you just try a little bit harder to make it happen. So you know already there should be some signs there about what's to come when we look at the research findings for this so.
Mel:
[4:35] Apply more ctgs to maybe see the only problem is is we haven't applied enough ctgs that's how come we haven't worked out that they work yet so maybe if we just put more on the answer will
Kirsten:
[4:48] Find the right people then yeah then it'll be okay so there's a cochrane review for this. There's four trials, as I said, 2001 to 2008. The numbers here are better than they were for the antenatal CTGs, but not as many as we have for the in-labour stuff. So it's 13,269. And it showed no difference in death rates. Any of the other measures about babies, seizures, admissions to the nursery, but a 20% increase in the cesarean section rate and a 10% increase in the use of vacuum or forceps for birth.
Mel:
[5:26] Right.
Kirsten:
[5:26] So we can- Are we surprised given that that's the same thing that we found for the in-labour stuff? Yeah.
Mel:
[5:34] So having an admission CTG increases the chance of cesarean and assisted vaginal birth with forceps or vacuum, but doesn't change the outcomes at all.
Kirsten:
[5:46] Correct.
Mel:
[5:48] Okay. So we need to apply more interventions just to get the same outcome if you've applied a CTG.
Kirsten:
[5:56] That's one way of looking at it. Now, unlike the other bits of research we've looked at so far, there is actually a recent update to this. Partly, I think, because in some parts of the world, people don't want to let go of their admission CTGs. And so somebody went, oh, well, prove it then.
Kirsten:
[6:13] I mean, I don't know if this is actually how this research happened. It's just the nice story I've come up with. So in Dublin, who have been central to a lot of the research about CTG monitoring, in 2018, they published a thing called the ADCAR trial. And that added another 3,000 women to the mix. And there were no deaths at all in that trial. So, you know, it doesn't make a difference to mortality. Don't know, it didn't happen in either of the groups. But again, there was absolutely no difference in any of the other outcomes for babies. But unlike the older stuff, there was no difference in cesarean section rate or instrumental births with this particular new set of information. And I've done a sneaky meta-analysis of this just for my own purposes. It's not published anywhere. I have a course that you can access it in if you want to pay to come and learn some more.
Kirsten:
[7:07] And when you meta-analyse it along with those four previous ones, again, no improvements in outcomes. It doesn't help putting on an admission CTG. The other thing to keep in the back of your mind with that information is the belief that if I hear something abnormal with the heart rate, then I should put the CTG on because that should improve outcomes. In essence that's kind of the situation with this group of people because the ones where the ctg was not normal on admission were the ones who ended up with continuous ctg use and despite that it didn't make a difference to outcomes so.
Mel:
[7:48] If we're asking the question whenever is ctg appropriate first we can already rule out the appropriateness of routine admission ctg there's not adequate evidence to prove that that makes any difference.
Kirsten:
[8:04] Correct.
Mel:
[8:05] We got that one. So what about if a woman has an epidural during labour? Would it be a good idea to put a CTG on then?
Kirsten:
[8:15] Okay. To answer that question, what you would need to do is design a trial where you took a population of women who had all had epidurals or were about to have epidurals and randomly select the use of CTG monitoring or intermittent auscultation. Once the epidural was established. That research has never been done. We do have, in amongst the trials, in labour trials that have been done, there are some women that had epidurals. It was at an earlier point in time in places where the epidural rate was low. So, for example, the Dublin trial, which is the biggest of the CTG in labour trials, the epidural rate was 3%.
Kirsten:
[9:05] So yes, there were women in the trial that had epidurals, but they really don't contribute in a meaningful way to the outcomes. So we have no evidence. Maybe it does, maybe it doesn't. Physiologically speaking, provided the woman's blood pressure is stable and she is well oxygenated, there's no real reason to believe that putting a CTG on should make any differences to outcomes in that particular situation. I think it's what I see in clinical practice is that with the onset of an epidural.
Kirsten:
[9:43] The care kind of shifts to kind of remote control stuff. Automated blood pressure cuff goes on, a pulse oximeter goes on the woman. So you can now do the observations while standing at the end of the bed. The CTG goes on, so you don't have to stop and do intermittent auscultation. And the midwife kind of retreats to the other side of the room and turns it back to the woman and does all of the backlog of paperwork that needs sorting out. Ostensibly so that the woman can sleep, because often that's what they choose to do just after they've got a good functioning epidural. But I think the CTG is considered useful at that point in time because it reduces the amount of work that the midwife needs to do. In a time where the midwife's wanting to just breathe a sigh of relief because, you know, I've probably got a couple of hours where the woman's going to sleep and all the machines that go ping are now set up to do that without me actually having to lay hands on her.
Mel:
[10:41] The only thing I can think of where I'm playing devil's advocate is I had a client who was planning a V-back at home and when I put the Doppler on, the heart rate was significantly high and remained so for long enough for me to recommend transfer to hospital. It remained high for about another 12 hours until which point all of a sudden the baby's heart rate absolutely crashed and we were wheeled out for cesarean section due to a uterine rupture. She had an epidural on board so she could sleep, exactly as you say, because of how long her labour had been. And in that scenario, I was like, whoa, that was good that the CTG was on. But as you said in one of the previous episodes, yeah, but if the CTG wasn't on, something else would have been done. Yeah.
Kirsten:
[11:35] Presumably there's not no fetal heart rate monitoring. The alternative would have been intermittent auscultation.
Mel:
[11:41] And what I'm getting at too is that everybody, I think, would have a story about a time where they believe a CTG saved the scenario or was significant in the scenario. So I guess what Kirsten and I are saying is that may be so that you identified times where a CTG created a change in the outcome, good or bad. But what we're saying is there's no universal evidence to suggest that this should be applied to everybody and that we can promise any particular outcome by the use of a CTG. But there are times where I do believe that it was fortuitous, where people went, whoa, luckily we had the CTG on. That's entirely possible. But what we're trying to get at here is that it's not well documented in the research.
Kirsten:
[12:29] Correct.
Mel:
[12:29] So that's epidurals. What about for women who are planning VBAC, vaginal birth after cesarean? Part of the policy around that is that women have continuous CTG monitoring. Have we ever looked at if that's a good idea or not?
Kirsten:
[12:46] We have. There is one trial. It's tiny. There were 50 women in each, so it's completely undersized in terms of its ability to detect anything, and they didn't do a sample size calculation to decide how big the trial should actually be to produce meaningful data. They just decided, we're going to do 100 because it's a nice number.
Kirsten:
[13:09] And not surprisingly found no difference. There were no cases of uterine rupture. There were no deaths. They didn't report on neonatal seizures, no other differences in terms of baby outcomes. The cesarean section rate was marginally higher in the group that had CTGs rather than intermittent auscultation, but it didn't reach statistical significance because when you've got a trial that's that small, unless you go from a cesarean rate of zero to 100, you're not going to get a statistically significant result. So the VBAC stuff is really more about absence of evidence rather than evidence that there is no difference between the two. When we look at the broader set of research, I've gone and read the fine print of them all to see whether vaginal birth after cesarean section was one of the reasons why women were included in the high-risk trials, and it's never mentioned. And I think there's a couple of reasons for that. One is that the base cesarean section rate was significantly less than it is now. So like the Dublin trial, at the end of that trial, the percentage of women who had cesarean sections as they gave birth at the end of that trial was 3%, which is just like gobsmackingly low.
Mel:
[14:31] I mean, at the time of recording now, Australia is nearly up to 40% cesarean section.
Kirsten:
[14:38] And so I think... So the number of women that would then line up for their next pregnancy who had had a cesarean section would be at best 3%. And of that group, a moderately high proportion of that would have, like the reason their cesarean section was done is something that's going to be a recurring problem for them. And so they need another cesarean section. So, you know, there might only be half of those people that it would be appropriate to even think about VBAC for. So now we've got one and a half percent of the population that's... And because the other thing that was going on during that period was that through until kind of the late 1980s, it was the once a caesarean, always a caesarean section was the belief. The idea was that it was just simply too unsafe to attempt labour and therefore thou shalt not and it was not offered to people. So, yeah, I think the potential pool of women having a VBAC who might be hidden in the data of the other research is probably very close to zero. So the only evidence that we've got is that one small trial from India, 2006. So at least it's half decently recent. It's only 20 years old. It's not 40. But, yeah, too small to be useful in terms of providing information.
Kirsten:
[16:02] The other way of looking at this research was to look at the relationship between heart rate patterns and uterine rupture. Can you predict in advance the woman who's going to have a uterine rupture if you're using a CTG compared to intermittent oscarotis or just using a CTG or then compare it with anything? These are the women that had a rupture. This is what their CTG looked like. These are the women that didn't. This is what their CTG looked like. In hindsight, now that we look back at it, could you see any patterns? And there were some differences, but there was such a broad overlap between the two in terms of abnormal heart rate patterns that it's just, it's not useful. If you did a repeat cesarean section for every woman that had an abnormal heart rate pattern who was having a VBAC, then you might as well just not attempt to VBAC because it was something like 80% of women had an abnormal heart rate pattern at some point in labour, most of which, as we know, 20 minutes later, will go back to being normal again and they're fine.
Mel:
[17:04] Yeah, I attend women as a private midwife. Having VBACs at home and there's been three scenarios where I've suspected uterine rupture based on changes in the fetal heart rate and we've moved into hospital and all of those took over 10 hours before anything more convincing arose and then when we finally did move to the caesarean section, it was identified that there was partial rupture recurring for these women. Slowly over time. So it seems as though that there are some changes in the heart rate, but what they are that indicate, are we having a rupture now? Will we have one later? Maybe this is just a quirk in the baby's free heart rate.
Kirsten:
[17:57] The handful of cases I've been involved in during my time in clinical practice was so completely obvious that, you know, a student midwife could have recognised them from the other side of the room um you know peeking between the fingers without actually listening to the heart rate it was quite clear that something seriously bad was happening and you don't need you know putting a ctg on that in that situation would have been counterproductive because you just needed to get to theater right now and it would have been pointless yeah.
Mel:
[18:30] That was a situation for us too you can hear it with your ears you don't need it printed out on paper to go oh yeah that does look weird wait let's wait three more minutes to get a good print out to see if it is weird it's like no that's clearly weird um yeah yeah so
Kirsten:
[18:45] This is one area this is one area that gets my goat which is literally what i have a picture of a goat on the blog post that goes along with the feedback story because so i hear so many stories of women who want to give birth in a hospital because they perceive it to be the safest option when they've had a previous cesarean section who are held hostage, you know, I will not care for you unless you have a CTG or well, all right then, but you can't get in the bath unless you have a CTG or you can't have this or you can't have that. And it's unethical because you cannot make a strong argument for feet CTG use for this group of women on the basis of the evidence.
Mel:
[19:28] I've seen that too, where women are attempting to do something that's outside of the policy and so they go okay we'll let you do that but you got to do this one thing for us first so Oh, big deep breaths.
Kirsten:
[19:43] And let's move on.
Mel:
[19:44] And let's move on. All right. Multiple births, twins. I mean, if women are fortunate enough to find a clinician who will actually support them to have vaginally born multiple babies, is there any evidence that the use of CTG during these labours would be beneficial?
Kirsten:
[20:05] This is the question that started all of this, Mel, because I was sitting in my consulting room one day in private practice with a couple and she had a twin pregnancy and we were in the third trimester and having our, you know, what we're going to do for birth chat and she wanted to birth vaginally and I was just, you know, you have a list, you get used to these things when you've been doing it for a while and was going through my list of things that would happen and would normally be recommended for labour with twins. And I said to her, and, you know, we'll recommend that you have continuous CTG monitoring in labour. And her husband went, why? Why? And I said, well, that's what the guidelines say. And he said, is there actually any evidence to show that that will make anything better? And I kind of went, I'm sure there must be, but I don't actually have any at my fingertips. Can you give me a couple of days and I'll email you what I find. I'll just go and, you know, look up something in the library.
Kirsten:
[21:14] I thought it was like, hold my beer, you know, like I thought this would be easy. Surely, there's such a consistently strong recommendation in all the guidelines. Surely, there would be a pile of evidence and there is none. So there's never been a randomised controlled trial that looked at just women with twin pregnancies. There are women with twin pregnancies who are included in the big high-risk trial groups, but they make up a small proportion of the overall population because twins aren't that common. And none of the trials analysed their data separately to anyone else's. So they were part of the Dublin trial, but this was the outcomes for women who had a multiple pregnancy. You can't do that analysis because it's just that information isn't available. Yeah, so I had to eat humble pie and go back and say, okay, well, that seems to be a guideline that's just based on people's opinions. It doesn't actually have any research evidence behind it. So yeah, it's kind of up to you to decide whether you would like that or not.
Mel:
[22:14] Oh and future kirsten discovers later that there's no evidence for hardly any of it
Kirsten:
[22:21] And and i was i was shocked that um firstly that there was no evidence because i considered myself a very evidence-based practitioner why would i have been basing my practice on this when there is no evidence and really shocked at the fact that i did not know that there was no evidence for something that I was doing on a daily basis and just taking for granted that I actually knew what the research said when clearly I didn't know what the research said.
Mel:
[22:53] Did they end up having a thing?
Kirsten:
[22:57] She had a lovely vaginal birth of her twins and she didn't have CTG monitoring and she gave birth to the first baby in the bath and then hopped out and gave birth to the second baby on a birth stool and it was lovely. All right.
Mel:
[23:11] Well, there you go. That's twins, guys. We have no more information for you because there is none. Surprise, surprise. All right. Oh, here's a doozy. Macronium stayed Lycor. So everybody go back there is an episode of meconium stained lycor in the podcast gosh for the the number eludes me now but meconium in the waters is what that episode is called
Mel:
[23:36] I've seen this I transferred a client to hospital once with meconium stained lycor it was clear when we started it changed we transferred out of precaution because I just wasn't sure why it changed and if there was a problem I thought maybe it'd be a good idea to be in hospital boy did we and she regret that in the end when we got there because of how much drama ensured not for her or her baby just how panicked the hospital was but there was a whole battle around we have to put the CTG on because you've got meconium stain lycor despite the fact that I've been telling them the whole time through her labor the fetal heart rate was normal I don't have concerns with the fetal heart rate and as you can see it's still normal by this intermittent auscultation. We're just here to proceed with this birth in this facility in case this meconium creates a problem for this baby but currently the baby does not seem to be having a problem. The amount of coercion and bullying that went on for that poor woman that wore us all down was catastrophic for her experience and we ended up going on to putting in all kinds of complaints and things. But this is what I'm emotionally invested in this question.
Kirsten:
[24:59] And even if there was really good evidence, it's still not okay to coerce somebody who's made a clear decision about what they want their care to look like.
Mel:
[25:07] Exactly. And she was saying to me, should I put this on? I was like, we've checked the heart rate. It, for all our knowledge, is normal. So I cannot, in good conscience, recommend to you that we even put a CTG on because all the checks we've currently done, check out. We're not here for concerns of the baby's heart rate. We're here because there's this potentially sinister meconium that I would like to make sure we have access to a pediatrician if it becomes a problem. And it wasn't a problem. if anybody's wondering about the end of the story the baby and the mother were physically well what they were not well with was the emotional impact of being treated so poorly in their labor but the the clincher was the obstetrician telling her that in the deepest darkest africa babies die and so if you don't have this ctg with this baby with meconium this is potentially what could happen to your baby, which is barbaric information and so inaccurate and so unfair. And so is there any evidence behind the recommendation to have a CTG if your baby has got meconium in the waters during labour?
Kirsten:
[26:16] There's been one trial. It was done in 19... Either 98 or 89, a while back, before the turn of the millennium, and it was done in Pakistan. It had 200 women in the trial, 100 in each arm, and it has never been published. The only reason that I and everyone else in the world knows that it exists is that the authors of the Cochrane Review knew about this research, and so they were given access to the unpublished data from the people who conducted this trial. So if you read the fine print in the Cochrane Review, you can find the information in there, but it's not like all of the other research in the Cochrane Review where I can pull up a paper and go through the details of exactly what happened. So I don't quite know all that fine print detail that I like to get my head around to know how much can I trust this information, I don't have access to and nobody else in the world does either, apart from presumably the people who've written the Cochrane review. And it made no difference to outcomes. Again, it's undersized. So maybe there was going to be a difference to the outcomes if they'd looked at 20,000 people instead of 200. But it certainly does not provide strong evidence that using a CTG will improve outcomes if there's meconium staining of the licor.
Mel:
[27:46] So yet another made-up idea for why maybe we should put a CTG on. All right. There you go, guys. We've done CTGs for meconium. Same answer, basically. Not enough research.
Kirsten:
[27:59] What's next on your list? Okay.
Mel:
[28:02] All right. So if I notice something unusual, so we're using intermittent auscultation and then we notice something unusual on the Doppler, is the appropriate next step to put a CTG on?
Kirsten:
[28:15] To answer this you would need to do a trial where the entry criterion was an abnormal, sounding heart rate of some description with intermittent auscultation and then half of those women would continue with intermittent auscultation and the other half would have ctg monitoring and who got which would be assigned randomly that research has never been done in some of the big randomized control trials that was one of the entry criteria so some of the high risk trials where you had to be high risk to be eligible to be in the trial. One of the risk factors was an abnormal heart rate heard on auscultation. And they were happy to randomly assign people to continuing with intermittent auscultation under those circumstances. And, you know, as we know from the overall mix of results for the in-labour stuff, there was no difference in outcomes. Because they haven't done subgroup analysis where they've looked at only the outcomes for that group of women. We can't really say with confidence that CTG monitoring did or did not work for that group of women, but we cannot go and stand on top of a hill and go, we have proof that you will do better. We do not have that evidence. We just simply do not know.
Kirsten:
[29:30] So I find it interesting. I've had some interesting conversations over the years with midwives who go, oh, but I only use CTGs when they're really needed. You know, like if I hear something abnormal on the Doppler, then they really need a CTG and go, well, girlfriend, let me set your Apple card because you've got absolutely no proof that what you're doing under those circumstances actually is going to make a difference. Again, it's another one of those myths that's quite hard to dispel because it's being ingrained in people that if the heart rate is abnormal, then they must have a CTG and that will make things better, whereas it isn't. And I think this is really context dependent. And so the research isn't going to capture any of the finesse here.
Kirsten:
[30:13] If you're at home and you've got you and your buddy midwife and things are fairly calm and relaxed and you've got time and plenty sets of hands and you hear something abnormal, but it's going to take you 45 minutes to transfer to a hospital, then you're just going to listen again with the next contraction. And maybe you're going to listen continuously over through two or three contractions in a row. And you're going to build up a pattern that tells you whether this baby's okay or not to continue. And so that's completely appropriate. If you're in a hospital environment where you're really short-staffed and you're currently looking after not just this woman, but the woman who's been plonked in the room next door who needs to get her induction started because she's got severe preeclampsia and she's got magnesium sulfate running and I really need to go and do a set of obs on her because she's in a really bad way. And I've just heard a bit of a tachycardia on your intermittent auscultation and you're in early labour and I thought I was going to be okay juggling the two because you're not really in established labour yet. But oh my God, I can't sit here and keep listening with intermittent auscultation. It's just easier if I whack the CTG on and then the guys out at the central monitoring station can look at it.
Kirsten:
[31:27] Well, because it makes sense under that set of circumstances to apply it. So it really is context dependent. If you have good staffing and good midwifery care, then in a non-emergent kind of situation, then continuing with good quality intermittent auscultation in the hands of somebody who knows how to do it well and how to interpret what they're hearing is fine.
Mel:
[31:50] Because I've heard that held over women's heads like, oh, yeah, we could do intermittent auscultation. But if we hear something weird, then we'll put the CTG on. You will have to. Yeah, you will have to put the CTG on.
Kirsten:
[32:03] Yeah, I mean, during the time when that research was being done and before CTGs were invented, midwives and obstetricians had ways of deciding who still needed a cesarean section or an instrumental birth even without having put a CTG on. You know, with the uterine rupture situation, there are times when the clinical situation is so obvious that you need to step in and intervene that stopping to start ctg monitoring would actually be extremely inappropriate you know if there's a cord prolapse you don't go let me go and grab a ctg machine and put some monitors on you know you just need to know is this baby currently alive if so let's go to theater now that's.
Mel:
[32:45] Right yep all right we have got two more questions So if women are opting for induction of labour, it would be beneficial to have the CTG monitor on during the induction.
Kirsten:
[32:59] What does the evidence actually say? Again, there's never been a trial where they've looked at induction of labour on its own and randomised people. And it would need to be a fairly modern trial because the way that we've gone about inducing labour has changed quite a lot over time. So at the time that most of the research about CTG use in labour was being done, we weren't using prostaglandins. The Dublin trial, which is the biggest of the CTG trials, Dublin didn't really believe in induction of labour. So their induction of labour rate was 3%, like their cesarean section rate, really low. I wonder if the two might have been linked in some way. That's a topic for another week. And that tended to be confined to women who were more than 42 weeks pregnant. What they did like, though, was oxytocin. So if women weren't going fast enough with their labour, then they would org-bent labour. So they'd start an oxytocin infusion to make the contractions stronger, particularly if it was their first baby. So they had 23% of women in the trial had an oxytocin infusion running.
Kirsten:
[34:11] So while we don't have any research that actually really helps us to know whether a CTG monitoring is a good option for people who are being induced or not, kind of the best that we've got is the fact that there is a subgroup analysis that's hidden in the bowels of the 1985 MacDonald paper about the Dublin trial that I've been able to pull out and do a bit of fancy research maths on that looks at for women who have an oxytocin infusion running and for women who don't, is there a difference in outcomes when it comes to whether they are monitored by CTG or intermittent auscultation? Now, I did this analysis specifically around neonatal seizures because it's the only one of the outcomes where CTG monitoring has had the glimmer of a whisper of a suggestion that it might actually be the better option for people. And the Dublin trial was the only trial that independently showed a better outcome in terms of preventing neonatal seizures. So if you look at the incidence of neonatal seizures in women who did not have oxytocin running during their labour, if they had intermittent auscultation, it was 15 seizures per 10,000 births.
Kirsten:
[35:30] Okay. If you had CTG monitoring, you didn't have oxytocin going, but you had CTG monitoring. It was 15 per 10,000 births. Now, you could do some fancy stats on that, Mel, but I don't think you probably need to, to get the point that if you don't have an oxytocin infusion running, there is no reduction in neonatal seizures by whacking a ctg on however this is where the story changes when oxytocin was being used if you had intermittent auscultation the rate of seizures was 160 per 10 000 births so slightly more than 10 times higher so significant increase which fits we know that this stuff is quite dangerous and that you can end up with too many contractions that last too long and are too close together with ctg use it was 36 so that i've done the stats on it it is a statistically significant difference the other important thing to notice there is that we've gone from 15 to 36 so if oxytocin is running and you're using a ctg it It doesn't prevent the rise in seizure rate.
Kirsten:
[36:52] It still happens. It's just that with CTG used compared to intermittent auscultation, the rise is not as big. There's the beginnings there of a suggestion that if oxytocin is being used and maybe therefore by extinction other medications that also stimulate contractions like prostaglandin, that maybe your baby is better off with CTG monitoring. Maybe.
Mel:
[37:21] So basically what we kind of can glean from that is use of oxytocin for induction significantly, almost 10 times, increases the risk that your baby will have seizures after it's born. But if you apply a CTG monitor during that induction process, that comes down to around 36, which is still about double the seizure rate that he hadn't had an induction. Well, it's not induction,
Kirsten:
[37:51] It's augmentation. It's oxytocin used for any reason, but mostly to speed labour up once it's already started.
Mel:
[37:58] Right. So the CTG could potentially provide a counteraction to the complications that can occur for induction of labour, but not completely as if you hadn't had the induction in the first place. Yep.
Kirsten:
[38:13] Now, you and I are both researchers, so we know there's this thing called generalizability, right?
Mel:
[38:20] Right. So this is the next thing I was going to talk to you about because inductions are done differently from facility to facility as well and country to country and clinician to clinician. That's one thing. But, yes, go ahead. Talk to us about generalizability.
Kirsten:
[38:35] Dublin in the early 1980s, maternity care does not look like that anymore. So we can't really take those findings and plonk them into Sydney in 2024 because the world is a different place. Now, there's a paper that was published the same year by Garcia in 1985, which reported on women's experiences of being in the trial and their experiences of the different kinds of fetal monitoring that they had. And they actually provide some background context information, which actually isn't in the actual trial paper. It makes for fascinating reading. So Dublin was the home of this thing that was called active management of labour, which is not active labour. It's not about getting off the bed and moving around. It's about having a vaginal examination every hour.
Kirsten:
[39:25] If you haven't ruptured your membranes by the time that the second vaginal examination happens, somebody does it for you. And if you haven't made one centimetre's worth of change between any of those vaginal examinations, then they start an oxytocin infusion. Part of that package was the promise that you would have a care provider be continuously present one-on-one with you throughout your labour, which was really lovely because that was not the standard at the time. But the Garcia paper makes it clear that that person was most often either a midwifery student or a medical student. So they're not actually a registered health practitioner with experience. They're a beginner who's just been plonked in the room to go, just say nice things and, you know, tell the woman she's doing a great job. You'll be fine. They've also been put in charge when it comes to intermittent auscultation of palpating contractions and telling when the woman's having the contraction and judging how strong they are and how long they last, which can be a bit tricky.
Kirsten:
[40:30] And this predates the invention of infusion pumps.
Kirsten:
[40:36] So oxytocin is delivered in a drip and it's delivered at so many mils per minute. And then you adjust that rate up or down depending on how the woman's body responds. So if there's not many contractions, you increase it. If there's too many contractions, you decrease it. Nowadays, we have fancy machines and you just type in 10 mils per hour and the machine does it for you. What used to happen, and I had the experience of doing this when I first started as a medical student, because I'm just a bit older than you, was that, you know, the drip comes through. There's a little drip chamber where you can see the individual drops falling out. And instead of mils per hour, we counted drips per minute. And so you would sit there and look at the little chamber and go six, seven, eight. Okay, that one's fine. and then you'd manually adjust the little stopcock up or down to change the rate. And it was fraught. Like you could easily get it wrong in one direction or another. So what could possibly go wrong with a bored medical student at two o'clock in the morning who's on his third day in birth suite being left alone in a room to do intermittent auscultation, count contractions and adjust the stopcock on the oxytocin infusion?
Kirsten:
[41:57] Why do you think maybe there are a lot of seizures in that group? Yeah. With the CTG, the midwife in charge can go wandering through and go, don't like the contraction pattern on that, knock that oxytocin back a little bit.
Kirsten:
[42:10] Whereas they just had to rely on the med student saying, oh, no, she's only having two in ten and they're not lasting very long. It's actually having six in ten and they're really intense. So, yes, there is this evidence that suggests that babies do better with intermittent auscultation. But if we provided care like that in Australia or anywhere in a high income country in the world in 2024, that would now be considered unprofessional practice and it would not happen. So what does that mean for those results? who knows. We just simply don't know whether they translate across to practice as it is in this day and age. So is there compelling evidence that women who are being induced will do better if they have CTG monitoring? There is not.
Mel:
[42:57] So if I was going to give the other questions that I asked you a ranking of appropriateness versus not, they would probably get a zero. Maybe this one would get a three or four on the ranking score.
Kirsten:
[43:10] Yeah, at least there's the beginnings of a suggestion. And it makes physiological sense that the risk here is that you produce more contractions than this individual fetus can cope with. And we don't like some babies are fine with five in 10. Others are not OK if there's more than two in 10 and you don't know that in advance. And so, you know, maybe having the closer monitoring that you get with a CTG because it is continuous, maybe it is actually better under those circumstances.
Mel:
[43:39] Maybe. So, okay, good. Half a reason. All right, final question to you, Kirsten. Is there ever a compelling good reason to have a CTG?
Kirsten:
[43:55] The answer to this one is actually quite deceptively simple but also extremely complex. And the answer is when the woman decides she would like a CTG.
Mel:
[44:07] Mm-hmm. Unless, of course, she's come to that conclusion because her care provider has so terrified her into the possible scenarios that will occur.
Kirsten:
[44:20] Or given her misinformation saying that, you know, your baby will die or it's much more likely to do badly or told her that you can't get in the bath or have a VBAC or use the birth centre or, you know, whatever the manipulation card is unless you have CTG monitoring. Yeah, those are not legitimate reasons. And, you know, whilst women don't have to be informed in order to make decisions and be taken seriously, obviously the system works best if they are given accurate information about pros and cons, understanding the context in which the decision is being made and the possible consequences of that as they're framing up their decision making. Because what we have is a system where...
Kirsten:
[45:07] We have really big problems about actually getting informed consent from people when it comes to CTG monitoring. And it comes up, it's been coming up in the literature since the mid-1980s. People started asking the question of, are we actually asking people for consent for CTGs? And the answer was no. And we're still seeing it. Stuff that's been published this year from Australia, where they asked women about their experiences with fetal monitoring. And there was a common theme of, I wish somebody had actually told me, or I wish they'd given me a choice because that was not what I wanted. And we need to stop doing that. And this idea that women who are considered low risk, well, they get this thing, and women who are high risk, they get this thing, all of that's wrong. Every woman, regardless of the degree of risk that's being calculated for her or not, should have a conversation about what the options are, what the evidence does and doesn't say and be given a choice and that choice be respected. And that should be simple. Because it does align with the fundamental principles on which your profession and my own is based, and yet it's not happening in practice.
Mel:
[46:21] Yes. The one big main reason to use a CTG is if the woman explicitly wants it and believes it's in the best interest of herself and her baby, because she's been given all the information and that's been her decision, rather than being clinician-led, because we don't have enough information to lead that decision-making process. With any information that's rooted in evidence except for maybe with induction of labour but part of me feels like that is more about counteracting the risk of augmentation and induction of labour than it does to say anything about the benefit of CTG. So as you pitched it to me early on when we were planning this episode you believe there's approximately one and a half reasons why a woman should accept a CTG at any time in their pregnancy or birth, which you've just highlighted today.
Kirsten:
[47:16] Yeah.
Mel:
[47:17] So for any clinician...
Kirsten:
[47:19] So reason number one, the woman chooses it. The half a reason is because oxytocin is being used either for induction or for augmentation. And maybe we can justify that with the evidence, but it's a bit fuzzy.
Mel:
[47:33] A bit fuzzy which is pretty much sums up all of the research around the use of ctg anytime in your pregnancy and birth a bit fuzzy yeah if we've taken anything away from these last three episodes Thanks so much, Kirsten. If you're a clinician listening today, I do believe that your clients would be adequately informed if they listened to the last three episodes from Kirsten regarding CTG, pregnancy, birth, and this one today that we've just asked the question of, is it ever a good idea? But fundamentally, the request and desire of the woman is what's going to be the biggest decision-making factor in the use of CTG.
Kirsten:
[48:14] And if you are a clinician and you're going, hang on, I don't believe any of this. I want to actually know a bit more of the fine print. I have a course for that called Fetal Monitoring for Maternity Professionals. And Mel will no doubt share a link to my website so you can find it where you can come and actually have me hold your hand while we take an extremely deep dive into all of the fine print so that you can have those conversations confidently knowing what the research actually says. Not like Kirsten from years ago, who got the surprise of her life when she discovered that there was no evidence.
Mel:
[48:50] Exactly. Thank you so much, Kirsten. All of that information will be in the show notes. And if you're on the mailing list for this podcast, you'll get all the evidence that we spoke about today. Don't forget Birth Small Talk, Kirsten's blog, which also covers a lot of this information. 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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