EBB 244 – Evidence on AROM, AVD, and Internal Monitoring

Amniotomy References:

• Kawakita, T., Huang, C-C, and Landy, H. J. (2018). Risk Factors for Umbilical Cord Prolapse at the Time of Artificial Rupture of Membranes. AJP Rep 8(2): e89-e94. https://pubmed.ncbi.nlm.nih.gov/29755833/
• Simpson, K. R. (2020). Cervical Ripening and Labor Induction and Augmentation, 5th Edition. AWHONN Practice Monograph 24(4): PS1-S41. https://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/s12884-019-2491-4
• Smyth, R. M., Markham, C. & Dowswell, T. (2013). Amniotomy for shortening spontaneous labour. Cochrane Database Syst Rev 6:CD006167. https://pubmed.ncbi.nlm.nih.gov/23780653/
• Alfirevic, Z., Keeney, E., Dowswell, T., et al. (2016). Methods to induce labour: a systematic review, network meta-analysis and cost-effectiveness analysis. BJOG 123(9):  1462-1470. https://pubmed.ncbi.nlm.nih.gov/27001034/
• de Vaan, M. D. T., ten Eikelder, M. L. G., Jozwiak, M., et al. (2019). Mechanical methods for induction of labour. Cochrane Database of Systematic Reviews 10: CD001233. https://www.cochrane.org/CD001233/PREG_mechanical-methods-induction-labour
• Simpson, K. R. (2020). Cervical Ripening and Labor Induction and Augmentation, 5th Edition. AWHONN Practice Monograph, 24(4), PS1-S41. https://nwhjournal.org/article/S1751-4851(20)30079-9/abstract 

Assisted Vaginal Delivery References:

• NHS article on forceps or vacuum delivery https://www.nhs.uk/pregnancy/labour-and-birth/what-happens/forceps-or-vacuum-delivery/
• Bailey, P. E., van Roosmalen, J., Mola, G., et al. (2017). Assisted vaginal delivery in low and middle income countries: an overview. BJOG 124(9): 1335-1344. https://pubmed.ncbi.nlm.nih.gov/28139878/
• CDC Wonder Database
• Feeley, C., Crossland, N., Betran, A. P., et al. (2021). Training and expertise in undertaking assisted vaginal delivery (AVD): a mixed methods systematic review of practitioners views and experiences. Reprod Health 18(1): 92. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8097768/
• Crossland, N., Kingdon, C., Balaam, M. C. (2020). Women’s, partners’ and health care providers’ views and experiences of assisted vaginal birth: a systematic mixed methods review. Reprod Health 17:83. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268509/
• Hook, C. D., Damos, J. R. (2008). Vacuum-Assisted Vaginal Delivery. Am Fam Physician 78(8): 953-960. https://www.aafp.org/afp/2008/1015/p953.html
• Tsakiridis, I., Giouleka, S., Mamopoulos, A., et al. (2020). Operative vaginal delivery: a review of four national guidelines. J Perinat Med 48(3): 189-198. https://pubmed.ncbi.nlm.nih.gov/31926101/
• Verma, G. L., Spalding, J. J., Wilkinson, M. D., et al. (2021). Instruments for assisted vaginal birth. Cochrane Database Syst Rev. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005455.pub3/full

Internal Monitoring References:

• • Euliano, T. Y., Darmanjian, S., Nguyen, M. T., et al. (2017). Monitoring fetal heart rate during labor: A comparison of three methods. J Pregnancy 2017: 8529816. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5368359/
  • Neilson, J. P. (2015). Fetal electrocardiogram (ECG) for fetal monitoring during labor. Cochrane Database Syst Rev 12: CD000116. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000116.pub5/full
  • Harper, L. M., Shanks, A. L., Tuuli, M. G., et al. (2013). The risks and benefits of internal monitors in laboring patients. Am J Obstet Gynecol 209(1): 38.e1-38.e6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3760973/
  • Bakker, J. J. H., Verhoeven, C. J. M., Janssen, P. F., et al. (2010). Outcomes after internal versus external tocodynamometry for monitoring labor. N Engl J Med 362(4): 306-13. https://www.nejm.org/doi/10.1056/NEJMoa0902748?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200www.ncbi.nlm.nih.gov
  • Frolova, A. I., Stout, M. J., Carter, E. B., et al. (2021). Internal fetal and uterine monitoring in obese patients and maternal obstetrical outcomes. Am J Obstet Gynecol MFM 3(1): 100282. https://pubmed.ncbi.nlm.nih.gov/33451595/
  • Bakker, J. J. H., Janssen, P. F., van Halem, K. (2013). Internal versus external tocodynamometry during induced or augmented labor. Cochrane Database Syst Rev 8: CD006947. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006947.pub3/full
  • van Halem, K., Bakker, J. J. H., VerHoeven, C. J., et al. (2011). Does use of an intrauterine catheter during labor increase risk of infection? J Maternal Fetal Neonatal Med 25(4): 415-418. https://www.tandfonline.com/doi/abs/10.3109/14767058.2011.582905

Rebecca Dekker:

Hi everyone. On today’s podcast, we’re going to talk about the evidence on three interventions during childbirth, artificial rupture of membranes, also called amniotomy, assisted vaginal delivery, also known as forceps or vacuum-assisted delivery, and internal monitoring.

Welcome to the Evidence Based Birth® Podcast. My name is Rebecca Dekker and I’m a nurse with my PhD and the founder of Evidence Based Birth®. Join me each week as we work together to get evidence-based information into the hands of families and professionals around the world. As a reminder, this information is not medical advice. See ebbirth.com/disclaimer for more details.

Hi everyone, and welcome to today’s episode of the Evidence Based Birth® Podcast. My name is Dr. Rebecca Dekker, pronouns she/her, and I’ll be your host for today’s episode. Today I’m so excited to bring some brand new evidence based information to you about three interventions. But, before we get started with the content, I have a really big announcement for you. We’ve been working on a secret project at Evidence Based Birth® since January of this year, and we are almost ready to make that project available to the public. The secret is that we have been writing and designing a brand new pocket guide all about the evidence on interventions in childbirth.

The Pocket Guide to Interventions is about the size of my hand, a little bit smaller. It’s going to be about 44 pages long, and it’s color printed, laminated, so it’s cleanable, reusable, and it’s on a handy little key ring so you can keep it packed in your birth bag, hanging at the nurse’s station or in your purse or a backpack. In this brand new Pocket Guide on Interventions, we cover everything from how interventions are like a toolkit, to what is informed consent, what are some medical biases and stereotypes you might be confronted with, and how do you advocate for yourself.

We also give a brief overview of each intervention so you know exactly what the interventions are and why they are sometimes proposed. And then in the middle of the pocket guide, we’re going to go in depth into the research evidence on every intervention used in childbirth, including the pros, cons, and alternatives of each intervention. I’m not going to list all of the interventions right now, but we cover the research on everything ranging from antibiotics to artificial rupture of membranes, forceps, vacuum, bladder catheters, cervical exams, fetal monitoring both internal and external, epidurals, IV fluids, management of the birth of the placenta, perineal massage, Pitocin, time limits in labor, and much more. So I’m really excited because it’s like in your hands a pros, cons, alternatives for every single intervention and it’s all based on the latest research evidence.

Then in the final third of the pocket guide, so the back third of it, we give additional important information including tips for writing birth plans, tips for if you have an epidural, how you can help prevent preventable cesareans, how to have a family-centered cesarean, and we also provide some last resort advocacy methods and scripts if you find yourself in a difficult situation where your rights are not being respected. And of course we provide you with all the research references and tons of additional resources. This is something that I would always want to have at a birth because I would have the safety information on hand to help me with informed consent on each of these interventions.

One of my favorite resources that goes along with this new pocket guide is a resource page where you can go to learn more about all of these interventions. It’s like an amazing repository of videos, podcasts episodes, and direct links to the studies themselves. And so this webpage is only for people who purchase the pocket guide.

On a side note, we have also updated our pocket guides to comfort measures and labor induction, and those will also be available this fall. So if you’ve been wanting to get your hands on one of these, they’ve been sold out for a while, they will be available in the coming weeks in a limited quantity. If you want to get all three of the pocket guides, you want the Comfort Measures, the Labor Induction and the Interventions, we will have a trio option where you can get them at a bigger discount. If you don’t want a trio, you can still buy the singles or you can mix and match whichever pocket guides you want, and we also have them in digital versions.

I’m so excited and I cannot wait to get these pocket guides out into the world and into your hands. We know from past experience that these pocket guides, the physical copies do sell out, so we encourage everyone to go and get on the waitlist. Just go to evidencebasedbirth.com/pocketguide and you can sign up for the waitlist and then you’ll receive an email shortly afterwards with all of the details about the date and the time that the pocket guides will be available. That waitlist page will also have an FAQ in case you have any more questions about the pocket guides.

So to celebrate the upcoming release of this Pocket Guide on Interventions, which I spent nearly a year preparing and developing, I’m going to share with you some of the new research on interventions that we have never published before anywhere else at Evidence Based Birth®, and this information is included in the pocket guide, but I wanted to make sure we got this info also on the podcast.

I had a lot of fun digging into the research evidence on amniotomy, which is called artificial rupture of membranes or AROM, assisted vaginal delivery, also known as forceps or vacuum-assisted delivery, and internal monitoring. So, today I’m going to get into some details on the evidence, pros, cons and alternatives of these three interventions.

As a content note, we will be talking about the benefits and risks of interventions including forceps and vacuum-assisted deliveries, which can be associated with birthing trauma for birthing people and babies. There is so much new information in today’s podcast that is not published anywhere else by EBB and I can’t wait to share this new research with you. Are you ready? Let’s go.

So let’s start with an introductory lesson about interventions and their use in childbirth, and we’ll kind of give you the EBB philosophy and some really important background information before we dive into those three interventions that I said I was going to cover.

I want to let you know that we do have a YouTube video of this podcast. So if you’re listening and you’d prefer to be able to see some of these intervention tools, I will be displaying some of them in the YouTube video. Just go to the Evidence Based Birth® channel on YouTube to see them.

So in the introduction of the pocket guide, we talk about how interventions are like a toolkit, we talk about informed consent, routine care versus evidence based care, biases and stereotypes and self-advocacy or saying no. When I say that interventions are like a toolkit, what I mean is that when we’re talking about interventions, we’re not labeling them as inherently good or bad in and of themselves. A lot of pregnant or expecting people can have a lot of fears related to interventions. So one of the things that I want to do with this pocket guide and this podcast is help take some of that fear away. Remember, each intervention is simply a tool that we can choose to use or not. Sometimes you need them and sometimes you don’t. So we’re going to be focusing on learning about these interventions as tools to help inform decisions about which interventions you need, don’t need, want, don’t want.

There is zero judgment here. Maybe some people won’t use any of these interventions we’re going to be talking about. Some people may be using them. There is no judgment. We’re just going to talk plain facts about the benefits and risks of different tools in your toolkit. But the problem is that some healthcare workers treat interventions like a bundle. They don’t see it as a toolkit where you pull out the tool that you need. Instead, it’s like you’re gifted a big bag full of presents and you have to use that entire bag full of presents all at once.

So typically what we see in many hospitals around the world is that the bundle of childbirth interventions that you’re expected to receive include having an IV or intravenous line, having Pitocin and fluids given through that IV, being hooked up to a continuous electronic fetal monitor, having someone break your waters. In other words, not letting them break on their own. Having regular cervical exams, having an epidural inserted and using other tools such as a bladder catheter, blood pressure cuff, oxygen monitor, and sometimes internal monitors. The bundle also typically includes strict time limits on labor progress. And if labor does not progress as quickly as desired, or the fetal monitor shows questionable results, performing a cesarean.

Now, me just listing all those interventions and how they’re used in a bundle might have made your heart rate go up a little bit or you might have felt a little, “Ugh. That sounds like a lot.” It is a lot, and that’s why we prefer to talk about interventions as a toolkit and selecting the tools that you need and not using the ones that you don’t need or don’t want. And so it’s important for you to remember that you have the power to decline any of the interventions you don’t want. So that’s some information from the introduction section of our Pocket Guide to Interventions.

Next, I want to move on to one of the three interventions that we’re going to be covering in today’s podcasts. That first one is amniotomy or artificial rupture of membranes, sometimes called AROM. So if you’re watching the YouTube video, I want to show you what the amniotomy instrument looks like. This is an amnio hook and it looks kind of like a long plastic crochet hook. It has this tiny sharp point at the end. So with a vaginal exam, they would insert this hook. It’s sterile when they take it out of the package and they would rupture or kind of prick to break the amniotic sac.

Your cervix must be at least a little bit open in order to perform an amniotomy. This is an extremely common procedure in both obstetrics and midwifery. It’s commonly done to help induce labor or to augment or strengthen contractions because it can release natural chemicals and hormones that may stimulate contractions. They also might break your waters artificially and use AROM if they’re going to be inserting internal monitors, which we’ll talk about in a little bit or if they want to look at the color of the amniotic fluid inside the sac. Now the fluid provides limited information since meconium stain fluid can be seen both in normal and abnormal situations.

For those of you watching the YouTube video, I also wanted to show you this is another way of breaking the waters. It’s called an AROM-cot or amnio cot. It’s a little finger glove that kind of goes on top of a normal glove, almost like a little condom for your finger. At the top there is a tiny little hook just like the one on the amnio hook that can also be used to break your water, so with that they’d be doing a cervical exam and using their finger with the little glove attachment to break the waters.

So what does the evidence say for artificial rupture membranes or AROM? Well, there’s actually a lack of evidence to support using AROM by itself as a labor induction method, especially if it’s your first time giving birth. There was a meta-analysis where they combined data from many different studies and looked at all of the different induction methods, and they found that if the cervix is favorable, meaning that if it’s a little bit dilated, if it’s thinning, then giving Pitocin plus AROM, breaking the waters together is the most effective method at having a vaginal birth within 24 hours.

There was also a meta-analysis of 15 randomized control trials comparing AROM to no AROM in spontaneous labor. So if you go into labor on your own, is there a need to break the waters? Research showed that AROM by itself did not shorten the first stage of labor, so did not make labor go by faster. It did decrease the use of Pitocin augmentation, but only in those who had given birth before.

So in looking at the research on AROM, amniotomy, or breaking the waters artificially, looking at the pros, it is a drug-free method so you don’t need any medications to have AROM. It’s pretty simple to perform and it’s usually not painful other than the fact that you have to have a cervical exam. If it’s being used in a spontaneous labor where you are not induced and you’ve given birth before, it might decrease the chances that you’ll need Pitocin later on.

Also, if you are being medically induced with Pitocin and you combine Pitocin with AROM, it can help increase your chances of having a vaginal birth within 24 hours. It’s also considered to be one of the safer induction or augmentation methods if you have a history of a prior cesarean because you’re not worrying about any medications that may increase your risk of uterine rupture.

So those are the benefits, but what are the risks of AROM? Well, once your membranes have been ruptured, there is an increased risk of infection if that time period goes on for a long time. So if you’ve had prolonged rupture membranes and your waters have been broken for a long time, the more time that goes by, the higher risk on your risk of infection. It also does not have any benefit in shortening labor if it’s your first time giving birth and you have a spontaneous or non-induced labor. So they may present it to you as something that will shorten labor. But if you’re in labor on your own and it’s your first baby, it’s not going to shorten your labor on average. It might in individual cases, but looking at research studies, it does not shorten labor.

There is one rare but severe complication called cord prolapse when the baby’s umbilical cord passes through the cervix before the baby. This happens at about 0.2% of births and it’s less common at term if you are more than six centimeters dilated when your waters are broken and when the baby’s head is engaged in the pelvis.

There’s also one other very rare complication. It’s if you have vasa previa, which is by itself a rare condition where the fetal vessels are exposed in the membranes and someone is going up and using that sharp hook to rupture the sac, they could rupture the vessels and the baby’s umbilical cord and that could lead to bleeding. Again, that’s a very rare complication.

So what are some alternatives to AROM? Well, you always have the right to let your waters break on their own. You can also use other methods to shorten labor such as movement, getting in a tub of warm water, using upright positions or having doula support. It is good to know though that if you do not want AROM, let your provider know before any cervical exam. Some providers do not ask permission before AROM. The hook might be right in front of them, or they might put on their finger without you knowing and they’re just checking your cervix, and pop your water breaks and it’s because they were performing an amniotomy without telling you. So if it’s important to you to not have an amniotomy, make sure you let healthcare workers know before any cervical exam that you do not want your water’s broken.

So next, let’s move on to assisted vaginal delivery. Assisted vaginal delivery is also known as operative vaginal delivery and sometimes called instrumental delivery. But it’s the use of forceps or a vacuum or ventouse device to assist with a vaginal birth. A vacuum or ventouse is not like a carpet vacuum, but instead it’s like a suction cup that can either be rigid or flexible and attached to a pump to create gentle suction on top of the baby’s head. With forceps or with the vacuum, the care provider uses the device while the birthing person is pushing to gently pull and guide the birth of the baby. An assisted vaginal delivery requires written informed consent, strict safety criteria and guidelines, and a local anesthetic or epidural for pain control.

Because an assisted vaginal delivery involves significant risks, it’s typically only used when absolutely medically necessary to prevent a cesarean. For example, if the birthing person is exhausted after a long pushing phase or to hasten the birth of the baby. For example, if there’s a medical emergency that requires the baby to be born quickly. However, sometimes we hear about it being used simply due to provider preference or to train medical students or residents.

Forceps and vacuum are now rare in many countries. In the United States it’s used pretty rarely, and in some places very few providers are trained in either method and it’s kind of becoming like a lost art. But in contrast, forceps and vacuum are still quite common in some countries. For example, in the United Kingdom, one in eight births is with the use of either forceps or vacuum.

For those of you who are watching on YouTube, I’ll just kind of quickly show you a few pictures you can find by doing just a simple Google images search on forceps and childbirth. You’ll see that the forceps typically look almost like salad tongs. Whereas a vacuum delivery in childbirth, you can see it looks like a little suction cup attached to some tubing that is used to create gentle suction.

I would, however, recommend being careful when you’re Googling things like forceps or vacuum-assisted delivery because a lot of the results will come up will be related to birth trauma, which is a rare but a possible serious side effect of assisted vaginal delivery, which we’ll talk about in a minute.

So what is the actual research evidence on assisted vaginal delivery? Well, we found a meta-analysis that combined 12 randomized control trials that compared any type of forceps to any type of vacuum. So we’re just comparing forceps to vacuum. They kind of found mixed results. So forceps were more likely to result in a vaginal birth than vacuum, but forceps had a higher risk of severe tears and a higher need for medication pain relief. There were no differences between groups in things like postpartum hemorrhage, Apgar scores, or a score of health from the baby, or umbilical cord pH which is another measure of infant health.

Forceps led to a lower rate of newborn trauma. So new babies were less likely to have jaundice with forceps as compared to vacuum. And they were less likely to have broken blood vessels under the scalp and in the eye with forceps compared to vacuum. There was no difference in NICU admission rates or newborn death rates between forceps and vacuum. So it seems that forceps are slightly safer for the baby, but result in a higher risk of severe perineal tears and are more painful for the birthing person.

I also found a systematic review that combined 42 research studies on families and healthcare providers experiences with using assisted vaginal delivery. Some studies found that experiences with assisted vaginal delivery were better than experiences with having an emergency cesarean. And then other studies found the opposite, that emergency cesareans were better experience than forceps or vacuum. The researchers summarize that a trusting provider patient relationship, good communication, patient involvement in decision making, and belief in the necessity of the assisted vaginal delivery are important factors in having a positive experience with vacuum or forceps.

Another study reviewed national guidelines from around the globe and they found the choice of which instrument do you use really depends on the clinical circumstances and the provider’s experience and comfort. They also found that there is consensus worldwide that episiotomies should not routinely be performed with an assisted vaginal delivery. There was a lack of consensus on protocols for the different devices. But in general, they agree that more than one device should not be used per labor. So you either pick vacuum or forceps, you don’t do both.

National guidelines were also consistent around the world in recommending that candidates for an assisted vaginal delivery must meet all of these criteria. Not just some of them, but all of them. And these criteria that must be met in order for assisted vaginal delivery to be performed include appropriate pain management, informed consent, a fully dilated cervix, membranes are ruptured, the baby’s head is engaged, there’s been a pelvic assessment, there’s been an assessment of the baby’s head molding and position, the birthing person has an empty bladder, they’re at least 34 weeks pregnant, the staff are skilled and experienced in the procedure, the staff are ready to provide newborn resuscitation if needed, and the provider is willing to abandon the procedure if it is not working.

So assisted vaginal delivery is such a complex procedure that I ended up devoting two whole pages to this inside the pocket guide, which is more than the other interventions. But it is kind of like two separate interventions, vacuum and forceps, which is why we kind of spent two pages on it.

But I found another study in Canada that was really interesting. The study looked at births between the years 2013 and 2019. They found that forceps deliveries had higher maternal trauma rates than vacuum deliveries, 25% maternal trauma rate with forceps versus 13% in a vacuum delivery including higher severe perineal tear rates with forceps. When looking just at newborn results, they found that newborn birth trauma rates were similar between methods, about 10 traumas per 1,000 births. But severe injury to the peripheral nervous system was more common with forceps than vacuum, 4.9 per 1,000 with forceps versus 3.4 per 1000 births with vacuum.

There was also something called subgaleal hemorrhage, which is when there’s an accumulation of blood between the skull and the skin and the baby’s head, and that is more common with vacuum. But overall, they found that rates of newborn trauma with both procedures were rare. So kind of summing up all of this research that’s been done all around the world on assisted vaginal delivery, what are the benefits of a forceps or vacuum-assisted birth? Well, the main benefit is that with a skilled provider, it can be an acceptable alternative to a cesarean. And if the procedure is successful, families may feel relief that a long labor or complicated birth is over.

However, there are quite a few risks with assisted vaginal delivery, which is why there is usually a written informed consent process with this. The risks include possible feelings of fear, distress, pain, and trauma. However, research shows that communicating, having trust in your provider and shared decision making can all help prevent trauma. The birthing person may experience postpartum urine retention or bladder swelling and distension immediately after the birth. Severe perineal tears can occur with both forceps and vacuum, but are more common with forceps and can lead to urinary incontinence, fecal incontinence, which means incontinence with your bowel movements, pain with sex and other pelvic floor disorders.

Episiotomy should not be routinely cut with forceps or vacuum, but if an episiotomy occurs, this can increase the risk of physical and emotional trauma. There is the risk to trauma to the newborn’s tissues or nerves of the face, head, neck, or shoulders. It is common to see broken blood vessels in the baby’s eyes, but this will usually resolve on its own. There are rare case reports of fatal birth trauma for newborns, and there’s always the potential that the procedure does not work and a cesarean will go on to be needed.

So what are some alternatives if a forceps or vacuum-assisted delivery is being recommended to you? Well, one alternative is patients using upright birthing positions and just having more time to push the baby out. In talking with a midwife who’s an EBB instructor in the Chicago area, Heather McCullough, she’s shared with me that assisted vaginal deliveries tend to be more common in some of the academic medical centers in Chicago. But as a midwife, she believes that most of those cases where forceps or vacuum are being used, in her clinical experience, a lot of those cases they just needed more time. But the culture there is one where they’re always trying to train the residents in how to do vacuum and forceps deliveries.

So sometimes it’s offered when it might not necessarily be necessary. And this is where we’re striking a balance between the need to train the next generation and how to do these critical potentially life saving procedures, but also we don’t want people to be told that they need one when they don’t need one.

Another alternative to an assisted vaginal delivery is to just choose a cesarean instead. Also, if there are problems with the baby’s position, and that’s why the pushing phase is taking so long, the provider could use their hands to adjust the position of the fetal head. This is called manual rotation, and this is one alternative to an assisted vaginal delivery.

Also, it’s important to know that there are things you can do to lower the risk of having an assisted vaginal delivery. Things that have been proven to lower the risk of needing an AVD include doula support, avoiding an epidural, using upright or sideline birthing positions, and having intermittent auscultation instead of electronic fetal monitoring.

Phew! So that was a lot. Assisted vaginal delivery is a big topic, but I’m so glad that we were able to summarize this info in the pocket guide so that it’ll be at people’s fingertips if this procedure is proposed to them.

So next I want to talk about internal monitoring. We’ve talked about electronic fetal monitoring before here at Evidence Based Birth®. We have a podcast and a signature article on this topic. So what’s internal monitoring? An internal fetal monitor or fetal scalp electrodes, sometimes abbreviated FSE, is a tiny spiral wire that’s placed on the fetus’ scalp to monitor the heart rate during labor. And I have one here with me. So it would be sterile. It would be inserted in this tube, and then the tube can be withdrawn. But if you look closely, you will see the tiniest little spiral and it kind of just hangs on the baby’s scalp like that, just the barest little poke.

The intrauterine contraction monitor, which I have on a package here. It’s also called an intrauterine pressure catheter or IUPC. This also is a small tube with a sensor right here that is inserted into the uterus. So you can imagine since we’re inserting things onto the fetal scalp into the uterus, your membranes must be ruptured and the cervix must be dilated enough for them to get these devices up through the cervix.

Now, the theory is that having internal monitors will lead to more accurate readings, which lead to less use of Pitocin or lower doses of Pitocin, but there’s no research on that just yet, which we’ll go into in a minute. Also, it’s important for you to know that the FSE, the fetal scalp electrode and the IUPC are sometimes recommended routinely to plus size people because there is a theory that it might be harder to wear the external belts and pick up an accurate reading of the heart rate or contractions. Now, we don’t have research to back that up, but that is sometimes that you will often see that in practice.

We do though have research randomized trials comparing these different monitoring options. So there was one meta-analysis of seven randomized controlled trials that compared the fetal scalp electrode with a special kind of analysis called wave form analysis versus regular electronic fetal monitoring where they put the belts on the outside of your abdomen. They found no substantial benefits to fetal scalp electrode for birthing people or babies. So they have found no benefits to this yet.

Another meta-analysis of three randomized trials compared the intrauterine pressure catheter versus the external contraction monitor, again the little monitor that goes on the belts on the outside of your abdomen, in birthing people with who were having inductions or they were having Pitocin to strengthen their labor. They found no difference in health outcomes between those groups, including no differences in how much the uterus was being stimulated by Pitocin or infection. So no differences in infection with the internal monitoring, but observational studies have found higher rates of infection with internal monitoring. I’ll talk more about that in a minute.

So what are the benefits of this kind of internal monitoring? Well, the FSE can be used to pick up the fetal heart rate if it’s been difficult to assess with the external electronic fetal heart monitoring. The IUPC, one of the benefits of this device is that it can monitor the actual strength or pressure of your contractions, which is expressed in Montevideo units unlike the regular external monitors, which only monitor how frequently you have contractions and how long they are not, how strong they are.

Also, some clinicians claim that if you’re moving around during labor, you’re less likely to have interference with the internal monitoring because there’s like a direct wired connection into the uterus. So you can move around, it’s just that you’ll have these tubes and wires coming out through your vagina.

As I mentioned earlier, randomized trials have not found higher infection rates with internal monitoring. Observational studies have, meaning when they look at large numbers of people with these and they’re not randomly assigned to have them, but it could be due to the higher risk populations or the ones that are more likely to be told they need internal monitoring, and that might be why they have higher rates of infection.

So what are some risks of internal monitoring? Well, a birthing person could develop a fever. Rates of fever with internal monitoring range from 12 to 36%. It also requires being tethered with cords to a monitoring machine. There’s a potential for a small cut, mark, or abscess on the baby’s scalp. Research so far has not shown that it improves infant health outcomes. And it requires artificial rupture of membranes if your membranes have not already broken on their own. There have been some case reports published on extremely rare, but serious risks including damage to the placenta or to the vessels in the umbilical cord, infection, and shock.

So the alternatives to internal fetal monitoring include the regular external electronic fetal monitoring, sometimes abbreviated EFM. There’s also intermittent auscultation, which is where they just listen by holding a doppler or fetoscope to your abdomen that’s less intrusive and lowers your risk of cesarean. There are also mobile or wireless electronic fetal monitors, but very little research on those so far. And then there’s something called intermittent EFM, which means you go on the external electronic fetal monitor for 20 to 30 minutes every hour. There’s sadly no research at all on that method.

So take a deep breath. We’ve just gone over a lot of information. I gave you a preview of the introduction to the intervention pocket guide, plus we did a summary of the evidence, benefits, risks, and alternatives of artificial rupture membranes, assisted vaginal delivery, and internal monitoring. Three topics that we’ve never talked about in terms of the evidence here at EBB before.

And so that’s it for today’s episode. Thank you for joining us to learn the research evidence on these interventions. Don’t forget to get on the waitlist for the brand new intervention pocket guide that is coming out on Tuesday, November 15. There are only a limited number of physical copies for people who want one, and you can get on the waitlist by going to evidencebasedbirth.com/pocketguide. That’s all lowercase, all one word, slash pocketguide.

There are so many interventions covered in this pocket guide. I only give you three of them. Next week we’re going to go over a few more that have not yet been discussed on the EBB podcast. So stay tuned. We’re going to continue this next week. Do a few more interventions together, and I’ll see you then. Thanks everyone. Bye.

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