Maternity - L&D, part 7: External Cephalic Version, Bishop Score, Labor Induction/Augmentation
by Meris Shuwarger BSN, RN, CEN, TCRN November 19, 2021 Updated: December 07, 2022 6 min read
This article focuses on labor and complications that may occur during labor and delivery. We'll focus on external cephalic versions, Bishop scoring, and labor induction and augmentation. The Maternity Nursing series follows along with our Maternity Nursing Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.
When you see this Cool Chicken, that indicates one of Cathy's silly mnemonics to help you remember. The Cool Chicken hints in these articles are just a taste of what's available across our Level Up RN Flashcards for nursing students!
External cephalic version
External cephalic version is an ultrasound-guided procedure to turn a baby to the normal vertex presentation using external means. When broken into its elements, the term translates as: external, that is, outside of the patient; cephalic, referring to the baby's head; and [in]version, meaning, here, to twist or rotate. Essentially, rotating the baby's head from the outside of the patient.
This procedure is implemented when we have a patient who has a baby in a breech position, meaning their head is up and their feet are down, which is not the ideal position for labor. An external cephalic version attempts to rotate the baby so the baby's head is down and their feet are up — the vertex position.
What is the procedure for an external cephalic version?
The procedure for an external cephalic version involves applying pressure externally to rotate the fetus into a better (vertex) position for labor and delivery.
When and where should an external cephalic version be performed?
The external cephalic version procedure is performed at 37 weeks gestation. The procedure should never be attempted preterm because up until full term, there's still time for the baby to move around and get in the optimal position on its own. Also, the procedure could trigger preterm labor, which could have serious consequences for patient and child.
External cephalic version should be performed in a hospital, due to risk of complications. If, for example, the patient goes into labor as a result of the procedure, care is nearby, including the possibility of delivering the baby immediately.
Complications of external cephalic version
External cephalic version carries a number of risks, as the doctor or midwife is attempting to manipulate the contents of the patient's uterus, that is, the baby. This presents a high risk of umbilical cord compression and placental abruption.
Umbilical cord compression
Umbilical cord compression occurs when pressure is put on the umbilical cord. The umbilical cord carries nutrients and oxygen from the patient to the fetus. When the cord is compromised, this can lead to fetal malnourishment or oxygen deprivation. In the most serious cases, there is a risk of death to the fetus.
Placental abruption is when the placenta is fully abrupted — separated — from the uterine wall.
External cephalic version nursing care
Administer IV fluids and tocolytics (medications used to suppress premature labor) to relax the uterus as ordered.
Continually monitor fetal heart rate (FHR) and maternal vital signs.
Administer rhogam to Rh-negative patients after the procedure, because of the potential for blood mixing and sensitization of the patient to fetal blood. It's important that the patient does not develop anti-Rh antibodies.
What is a Bishop score?
I WISH my BISHop score would be high enough to induce labor!
A Bishop score is used to determine maternal readiness for labor induction based on cervical readiness. An assessment of the cervix is made to determine how close the patient is to labor and delivery.
What are the components of a Bishop score?
The components of a Bishop score are cervical consistency, cervical dilation, cervical effacement, cervical position, and station of presenting part.
How is the Bishop score affected by multiparous and nulliparous patients?
The patient's personal history also influences the score — a patient who is multiparous, meaning they have had babies before (“multi” meaning more than one; “parous” referring to delivery or birth) is going to be marked as being ready for labor induction with a score of 8 or higher.
A nulliparous patient (no prior deliveries) is going to require a score of 10 or higher to be considered ready for labor induction.
How is scoring done to get a Bishop score?
Cervical components are given scores ranging from 0 to 3, with the exceptions of position and station, which are given scores of 0 to 2. The higher the score, the more likely the situation is optimal for delivery. A lower score indicates a cervix that is not ready for delivery or labor induction.
Labor induction and augmentation
For labor induction and augmentation, we're going to focus on two methods — cervical ripening and amniotomy — as well as use of the medication oxytocin.
What is cervical ripening?
Cervical ripening is preparing the cervix for induction, that is, getting the cervix more ready for labor.
Cervical ripening involves procedures that promote cervical softening, dilation, and effacement. These can include the use of chemical agents and/or mechanical methods.
Chemical agents used in cervical ripening
Chemical agents used in cervical ripening include prostaglandins such as misoprostol (brand name Cytotec). Misoprostol is a medication that softens the cervix and helps it to dilate and efface. (Misoprostol is also indicated as an antiulcer agent. Note the black box warning for patients who might not know they are pregnant as misoprostol can induce a miscarriage.)
Nursing care for cervical ripening using prostaglandins
A risk when using prostaglandins is uterine tachysystole or uterine hyperstimulation. This is when the uterus becomes over-excited — contractions are either too strong or happening too frequently. This can put the patient at risk for uterine rupture. Taking the patient off prostaglandins is the first step if uterine tachysystole or uterine hyperstimulation is suspected.
When using prostaglandins, it is also important to monitor both FHR and the patient's contractions.
For more on labor-related and other pharmacology basics, check out our Pharmacology Second Edition Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.
Mechanical methods used in cervical ripening
Mechanical methods for cervical ripening include balloon catheters, dilators, and membrane stripping.
If you recall how a Foley catheter works, a balloon catheter functions similarly. The catheter is passed through the cervix, and then a balloon on the end of the catheter is slowly inflated to put pressure on the cervix from the middle (inside) to try to help it dilate.
Cervical dilators are used to gently widen the cervix and exert pressure. These actions stimulate the release of natural prostaglandins.
Membrane stripping is a procedure where the provider inserts a gloved finger into the patient's cervix and rubs or separates the membranes that connect the uterus and the amniotic sac. This technique releases natural prostaglandins and helps ripen the cervix.
What is amniotomy?
Amniotomy is the use of a sharp instrument to rupture amniotic membranes. This is an artificial means of causing the water to break in preparation for delivery. Remember, any sort of “-otomy” is a puncturing or laceration. An amniotomy is a laceration of the amnion (the membrane that forms a fluid-filled cavity (the amniotic sac) enclosing the embryo). In this procedure, a sharp instrument is used to poke a hole in the amniotic sac, rupturing the membranes.
Patient risk for an amniotomy
Whenever something from outside the body is introduced to the inside, there is a risk for infection (in this case, chorioamnionitis).
Also, when the amniotic membrane ruptures and the fluid shifts (when the waters break), there is a change in pressure — the barrier has been broken between the outside and the inside. This can present a risk of cord prolapse, if the cord is partially sucked out when the pressure changes as the membranes are ruptured.
Nursing care for amniotomy
Make sure to monitor FHR before and immediately after amniotomy for bradycardia and variable decelerations.
It is also important to ensure that the presenting part of the fetus is engaged prior to the amniotomy. An amniotomy is not performed without full engagement.
Because of the risk for infection, it is important to check the patient's temperature every two hours, or per facility policy, looking for any signs of infection after the amniotomy.
What is oxytocin?
Oxytocin is a hormone created by the body naturally during labor that increases the strength, frequency, and length of uterine contractions. It is also used to control postpartum bleeding by firming up the uterus after delivery.
Oxytocin can also be administered in a synthetic form through an IV to augment or to induce labor.
Nursing care when administering oxytocin
When administering oxytocin, it is important to continuously assess the status of the baby by monitoring FHR and the patient's contractions.
One risk of using oxytocin to augment the contractions is overstimulating the uterus, which, as noted above, could lead to uterine tachysystole. In the event of uterine tachysystole, discontinue the oxytocin.
Additionally, discontinue oxytocin:
- If contractions occur more than every two minutes
- If contractions last longer than 90 seconds
- If contractions have an intensity greater than 90 millimeters of mercury using an intrauterine pressure catheter
- If, during a resting tone (meaning when the uterus is not contracting), that resting tone is greater than 20 mm millimeters of mercury between contractions
Essentially, discontinue oxytocin if the contractions are happening too frequently, if they're lasting too long, if their strength is too high, or if the resting tone is too high.
Another way to calm a hyperstimulated uterus is to administer terbutaline. Terbutaline is a tocolytic, which is used to help to relax the uterus.
Also notify the provider.
Hi. I'm Meris with Level Up RN. And in this video, I'm going to be talking to you about external cephalic versions, Bishop scoring, and labor induction and augmentation. I'm going to be following along with our maternity flashcards. These are available on our website, leveluprn.com. If you don't have a set for yourself, you can grab them there. And if you do have a set of your own, I would invite you to follow along with me. I'm starting in the labor and delivery section here, so be sure that you are in the right section.
Okay. So first up, let's talk about an external cephalic version. So let's just break down what does this even mean? These are a lot of words that I don't know what they mean. So let's talk about it. External, meaning from the outside of mom. This is not going to be an internal or invasive procedure; cephalic, referring to the baby's head; and inversion, meaning to to twist or rotate. So this is rotating baby's head from the outside of mom.
So really, what this is is when we have a patient who has baby in a breech position, meaning their head up, feet down, this is not the ideal position for labor. And it's possible to do an external cephalic version to turn the baby from that position into the vertex position, meaning head-down position. That is the optimal position for labor.
This is not without risk, though. So think about the idea that you are going to be manipulating the contents of mom's uterus. So specifically, the doctor, the provider, the midwife is going to be attempting to manipulate the baby. But there's other stuff in there, right, specifically, the umbilical cord and the placenta.
So when an external cephalic version is done, there are significant risks. And you will see here that we have bolded those risks for you because they're very important to understand. So there's a high risk of umbilical cord compression and placental abruption. We can fully abrupt that placenta from the uterine wall, meaning separate it from the wall because of this external manipulation. So this is very high risk, and that means that we should be doing this in a hospital.
Now, when I say we should be doing this, we as nurses are not doing this. I mean, more colloquially the use of the word we.
So this should be done in a hospital so that if something goes wrong, if we see this complication happen, or if mom were to go into preterm labor as a result of this, then we would be able to take care of mom and baby, right? We can imminently deliver right there. We can provide supportive care right there. Now, this should be done at 37 weeks gestation, give or take a little bit here and there. But we're not doing this preterm, right? We're not doing this before the pregnancy has come to full term because, first of all, there's still time for baby to move around and get in the optimal position. And secondly, we don't want to trigger preterm labor. That would be very bad.
Now, what are we going to do as nurses? We're going to continuously monitor fetal heart rate and the maternal vital signs, right? Make sure baby and mom are both doing okay. After this procedure is done, we need to give Rho-GAM to Rh-negative moms because there is that potential for blood mixing. So we need to make sure that mom does not develop those anti-Rh antibodies, right? That's very important.
And then also can give IV fluids and tocolytics, which are medications that relax the uterus, as ordered. That's just going to be per order. So just remember, we're doing this in a hospital because of the risk for complications.
Okay, moving on to Bishop scoring.
So the Bishop score is a score that helps us to determine the maternal readiness for labor induction, right?
So we're going to assess the cervix, and we have some components here. We have cervical consistency, cervical dilation, cervical effacement, cervical position, and the station of the presenting part. And each of these things are going to be given a score from 0 to 3, except for position and station, which are given a score of 0 to 2. This is less important. I'm just giving you kind of the background information. If you were to be a labor and delivery nurse, you would definitely need to know how to do Bishop scoring.
But for these purposes, we need to understand, what does it mean? So either the Bishop score can indicate that we are ready to have a baby, things look good, we are in optimal position to deliver, or not ready. So this is not a favorable cervix for labor induction.
Now, how do we know if you are in a good position or not? Well, it's going to be based on the score and the patient's personal history.
So a patient who is multiparous, meaning they have had babies before-- so multi, meaning more than one, right, and parous, referring to delivery or birth. So a multiparous patient is going to be marked as being ready for labor induction with a score of 8 or higher.
But a nulliparous patient, null meaning zero, parous meaning birth, so nulliparous, meaning no prior deliveries, is going to require a score of 10 or higher to be considered ready for labor induction.
So we have a nice Cool Chicken hint down here at the bottom that helps you remember what the Bishop score is for. It's I wish my Bishop score would be high enough to induce labor. There's a lot of scores and different kind of metrics in maternity nursing, so it can be difficult to remember which one is for which thing.
Now, moving on to the actual discussion of labor induction and augmentation, we're going to talk about two methods here.
First, we're talking about cervical ripening. So kind of a weird term, not my most favorite term in the world. It makes me think of fruit, but that is the point, right? Is the cervix ready for induction? So we can ripen the cervix, meaning get it more ready for labor.
And this is typically done with chemical agents like prostaglandins, the big one here being misoprostol. Brand name, I think, is Cytotec. You'll hear that frequently. That is a medication that is going to soften the cervix and help it to dilate and efface a little bit more.
And then there are also mechanical methods, which would include balloon catheters, where-- you know how there's a balloon on the end of a Foley catheter? Same idea here. It's going to be passed through the cervix, and then that balloon is going to be slowly inflated to put pressure on the cervix from the middle and try and open it up, right, to help it dilate. And then there's also cervical dilators and membrane stripping.
Now, the biggest thing that we need to be worried about when we use prostaglandins, in particular, it's going to be something called uterine tachysystole or uterine hyperstimulation.
Hyperstimulation is a really good way to talk about it. So the uterus is overexcited, right? It is doing the most. So those contractions are either too strong or happening too frequently. It's really scary and can put the patient at risk for things like uterine rupture. So if we suspected that the patient was experiencing uterine tachysystole, we would want to remove those prostaglandins if they were still in there. That would be the number one thing to do there.
Now, another way that we can talk about labor induction and augmentation would be something called an amniotomy. So remember, any sort of otomy is going to be a puncturing or a laceration of some sort. And this is going to be of the amnion. So this is going to be using a sharp instrument to poke a hole in the amniotic sac, essentially, right? So we're rupturing those membranes.
Essentially, we are artificially causing the water to break is what an amniotomy is.
Now, when I introduce something from the outside to the inside, I have an increased risk for what? Infection, right? I have an increased risk for infection. But also, when the water breaks, when that amniotic membrane ruptures and all that fluid shifts, there is now a difference in pressure, right? We had a difference in pressure from the outside and the inside. And now we have torn that membrane open, and things are moving. We have a risk for cord prolapse. Remember that the cord could get kind of sucked out when that pressure changes as the membranes are ruptured.
So we need to make sure that we are assessing the fetal heart rate throughout this whole process to make sure that it's staying stable.
Also, as far as nursing care goes, we need to make sure that the presenting part of the fetus is engaged prior to the amniotomy. We're not doing this without full engagement here. And then, like I said, we're going to be monitoring that fetal heart rate the whole time.
And because of the risk for infection, I'm going to be checking mom's temperature every two hours, or per facility policy, because I want to check and see if we have any signs of infection after that amniotomy.
Now, moving on to this last card that we're going to cover here, we're talking about oxytocin.
Now, oxytocin is a hormone created by the body naturally during labor. So we can actually administer a synthetic form of it through the IV to augment or to induce labor. So same idea as the natural stuff produced in my brain, but this is going to be the artificial version of it. This is going to increase the strength, frequency, and length of uterine contractions.
So all of that's going to help us move in a forward direction when it comes to delivering that baby. But oxytocin is really great because it can also be used to control postpartum bleeding. It can be used to help firm up the uterus after delivery. So this is a medication that if you work labor and delivery or postpartum, you're going to see it a lot.
Now, what do I need to know when I have a patient receiving oxytocin? Well, again, I want to know about the status of baby, right? I want to constantly be monitoring fetal heart rate and also contractions.
Because again, a risk of using oxytocin to augment the contractions is we can overstimulate the uterus and end up with uterine tachysystole.
So if we have uterine tachysystole, we need to discontinue the oxytocin. We have it here for you in big, bold, red letters that stand out very strongly on this card.
You need to discontinue the oxytocin if contractions occur more than every two minutes, if they last longer than 90 seconds, if they have an intensity greater than 90 millimeters of mercury using an intrauterine pressure catheter, or a resting tone, meaning when the uterus is not contracting, that resting tone is greater than 20 mm millimeters of mercury between contractions. So a lot of thing that I just told you there. But if the contractions are happening too frequently, if they're lasting too long, if the strength is too high, or the resting tone is too high, all of those things mean I got to turn that oxytocin off right now.
That's your big nursing consideration in that instance. And then I can notify the provider and do all of those other great things. But my primary action is going to be stopping this so we don't make it any worse. Also on this card, we say that you can administer terbutaline to decrease uterine activity if needed.
Terbutaline is a tocolytic, so it is going to help to relax the uterus. So this can be given-- if we do have that hyperstimulation, we can help to kind of calm things down.
Okay. I hope that review was helpful for you. And to see if it was or not, I'm going to ask you some quick quiz questions to test your knowledge of the key facts that I just gave you. So get your thinking caps on.
Okay. So first up, I want you to name a complication of an external cephalic version. So I gave you a couple, so just name one. What is the Bishop score that indicates maternal readiness for labor? And remember, there are two different scores, so think about that one. Name a complication of amniotomy. I gave you two, so name one of them. I want you to imagine that you are caring for a patient who has been receiving oxytocin. You are assessing their monitoring, and you see that contractions are happening every two and a half minutes. They last for 60 seconds. And you are going to use your smart nursing judgment here, and you're going to think about should the oxytocin be continued or should it be discontinued, based just on those two pieces of information?
Thanks so much and happy studying.
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