External Cephalic Version (ECV)

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Background / Intro

  • Breech presentation occurs in about 3-4% of term pregnancies, with a significant number of these patients delivery ultimately by cesarean. 

  • Previously on the podcast, we covered considerations for singleton breech vaginal delivery. While that was a fun one to talk through, as we mentioned then, breech delivery is NOT the standard of care. So how do we avoid cesarean?

  • External cephalic version is the answer! Essentially, using pressure on the pregnant person’s abdomen to achieve movement of the fetus to cephalic presentation. 

  • In order to offer this service, ACOG recommends an evaluation of presentation beginning at 36’0 weeks. Check out PB 221 for more reading.

Considerations prior to ECV

  • Patients who are good candidates for ECV are:

    • At least 37’0 and EFW > 2500g. 

      • Spontaneous version after this GA is less likely.

      • Risk of reversion to breech is significantly lower after this GA or lower than this EFW.

      • If complications arise, the infant is term and can be delivered emergently with less concern regarding sequelae of prematurity. 

    • Of higher parity

      • Multiple studies have reported positive associations between multiparity and success of ECV. 

    • In transverse or oblique presentations

      • While breech is not a contraindication by any means, traveling a little less far makes it easier!

    • With less cervical dilation, and of higher station

      • Babies lower in the pelvis are tough to turn!

  • Things you might think make a difference, but actually are less important:

    • Placental location

      • Studies are mixed in this regard; some authors have found improved success with posterior placentation, while others have found no association. 

    • Amniotic fluid volume

      • This was one I always heard about in residency!

      • While it makes intrinsic sense that higher levels of fluid would lower success rates, studies have not actually demonstrated this conclusively. 

    • Maternal obesity

      • Another controversial topic where studies have been mixed in terms of predictors of success. 

    • Obesity

      • Some authors 

    • TOLAC candidates

      • The most recent interaction of the ECV bulletin addressed this question, noting there’s limited evidence for women with a preexisting uterine scar on ECV. However, in four trials, no cases of uterine rupture from ECV were reported, so it’s reasonable to offer. 

    • Ongoing labor

      • There is also limited evidence that ECV can be successful during early labor, lowering cesarean delivery rates and reducing hospital length of stay. 

Counseling for a procedure - risks and benefits

  • Benefits

    • Certainly one benefit is the option of avoiding cesarean delivery! There is a significant reduction in cesarean birth rate for women who have successful ECV in randomized studies. 

      • Interestingly, the risk is still higher for cesarean in the ECV population compared to those who present with a fetus in cephalic presentation.

    • This also comes with the benefits of greater likelihood of vaginal delivery - most notably, fewer hospital days and lower odds of endometritis and sepsis. 

    • The success rate of ECV in trials is about 60% -- so a little better than 50/50. 

  • Risks

    • Discomfort certainly is the biggest consideration -- we’re going to mash on your abdomen now! Pain medications parenterally or the use of epidurals can help reduce this element. There even is evidence that epidural anesthesia may increase success rates.

      • This should particularly be considered for women who have an unsuccessful ECV at 37 weeks, but wish to retry at 39 weeks. A placement of an epidural, followed by ECV attempt, which if unsuccessful provides anesthesia for cesarean delivery. 

    • Fetal heart rate abnormalities - fortunately, these are often transient decelerations that resolve with a pause or cessation in the procedure. 

    • Additional serious risks - placental abruption, umbilical cord prolapse, membrane rupture, stillbirth, and fetal-maternal hemorrhage have all been reported after ECV; however, all occur at rates of less than 1%. 

    • Need for emergent delivery - because of the rare risks above, women should be counseled that there is the very rare possibility of emergent delivery when ECV is attempted. ECV should only be performed in places where cesarean is readily available. 

After consenting your patient, prepare yourself for a procedure!

  • Step 1: get an NST!

    • Certainly a non-reactive or suspicious NST pre-procedure would be a reason to re-consider doing something that might cause the fetus to react poorly. 

  • Step 2: consider a cervical exam

    • If your patient has advanced cervical dilation, and you end up in the sticky situation of causing membrane rupture, it’s good to know if that 3cm cervix might drop a cord! 

    • Additionally, if you’re doing an ECV at 39+ weeks, this will let you consider what to use for induction subsequently. 

  • Step 3: ultrasound

    • Do a quick survey. Take a look at a number of things, including:

      • True presentation: frank vs complete breech, transverse, oblique. 

        • What are frank and complete breech?

          • Frank we remember this as “Frank smells his feet.” This is the “pike” presentation where the fetus is maximally extended legs and flexed at the hips.

          • Complete this is the classic cross-legged sitting position.

      • Fluid volume

      • Placental location

  • Step 4: orders!

    • Medications for ECV:

      • Pain medications -- as we mentioned above, can be considered in the form of parenteral meds or epidural anesthesia. If IV meds are given, be aware of the consequences on fetal heart rate of the med you’re giving. 

      • Tocolytics -- classically terbutaline, the B2-agonist. With relaxing the uterus, a randomized trial found that terbutaline doubled the chances of a successful ECV. 

        • There’s not much data regarding other uterine relaxants, but be aware that the beta-agonist effect of terbutaline often causes tachycardia -- so avoid in patients where that is contraindicated!

      • RhoGam -- we’re essentially inflicting trauma on the uterus. Check a type-and-screen beforehand. If delivery won’t be performed in the next 72 hours, a dose should be given.

  • Step 5: procedure time!

    • The procedure can be accomplished with one or two people.

    • Use LOTS of gel on the maternal abdomen to prevent trauma to the skin and facilitate easy ultrasound access for fetal heart rate checks. 

    • Classically, the procedure involves lifting the breech out of the pelvis with one hand, and then using pressure on the fetal head to facilitate a forward or backward roll. 

      • The procedure is successful when cephalic presentation is accomplished.

      • The procedure should be abandoned if there is prolonged bradycardia, extreme maternal discomfort, or if a few attempts have been unsuccessful. There’s no “right or wrong” number but having attempted many of these, you get a sense of whether they’ll roll or not. 

      • A great video of technique can be seen at https://www.youtube.com/watch?v=aWTmxPV15DI

    • Usually, institutions will have a monitoring protocol post-ECV attempt -- ACOG recommends at least 30 minutes of continuous monitoring, regardless of success.