External Cephalic Version

CHAPTER 167 External Cephalic Version



Andrew S. Coco


In about 4% of term pregnancies, the fetus is in the breech position. Because the risk of complications with vaginal breech delivery is generally considered high, almost 90% of these fetuses are delivered by cesarean section without a trial of labor. Practiced since the time of Aristotle, external cephalic version (ECV) is a procedure that externally rotates the fetus from a breech presentation to a vertex presentation. Trials of ECV conducted over the past 25 years demonstrate an extremely strong safety record, a success rate of about 60%, and factors predictive of success and failure (Box 167-1). As a result of these studies, as well as the widespread availability of ultrasonography, electronic fetal monitoring, and effective tocolytic agents, ECV has made a resurgence. In addition to reducing cost and being safe and effective, the manual skills to perform ECV are easily acquired. Despite these favorable features, ECV is still underused. In fact, breech presentation is the third most frequent indication for cesarean section (after labor dystocia and repeat cesarean), and it accounts for 12% of the cesarean sections in the United States. Routine use of ECV could substantially reduce the rate of cesarean section, even in patients undergoing vaginal birth after cesarean (VBAC; however, see section on Relative Contraindications). ECV can be performed in basically any setting that has an ultrasonography machine and an experienced clinician (comfortable with ultrasonography and ECV). Clinicians must also be equipped and prepared for cesarean section if the need for an immediate delivery arises.



Box 167-1 Factors Predictive of Successful and Failed External Cephalic Version



Factors Predictive of Successful Version



Increasing parity (most consistent factor in studies)

Normal amount of amniotic fluid (may be linear correlation between success rate of ECV and AFI, i.e., higher success rate with increasing AFI)

Fetal presentation (success rate with transverse lie approaches 90%)

Unengaged fetal part

Earlier attempts at ECV (increase success rate, but also increase risk of spontaneous reversion to breech)


Factors Predictive of Failed Version



Engaged fetal presenting part*

Difficulty palpating the fetal head*

Uterus tense to palpation*

Maternal obesity

Cervical dilation

Anterior placenta

Anterior or posterior positioning of fetal spine

Descent of breech into pelvis

Decreased AFI

AFI, amniotic fluid index; ECV, external cephalic version.



* The success rate is >90% if none of the factors marked by an asterisk is present and <20% if two of these factors are present. There have been no successful ECVs when all three factors are present.



Indications



• Low-risk gestation at 36 weeks or more, by good dating criteria (at 36 weeks, likelihood of spontaneous version is low; alternatively, at 36 weeks, complications of immediate, iatrogenic, even preterm delivery are not severe).

• The type of breech (e.g., frank, complete, footling) is not a factor in determining suitability. Women with a fetus in transverse lie are also excellent candidates, as are those who are attempting VBAC (however, see section on Relative Contraindications).

NOTE: To perform ECV, it is preferable that the diagnosis of breech be made before the patient is in active labor! The further the breech is engaged in the pelvis, the more difficult the ECV; therefore the clinician should screen for breech, at least with Leopold’s maneuvers, in every pregnancy near term.



Contraindications



Absolute



• Indications for cesarean delivery aside from fetal presentation (e.g., placenta previa)

• Major uterine or fetal anomaly

• Nonreassuring fetal monitoring pattern

• Multiple gestation

• Abruptio placentae

• Ruptured membranes


Relative



• Suspected intrauterine growth restriction

• Decreased amniotic fluid volume

• Maternal cardiac disease

• Maternal hypertension

• Previous cesarean delivery (in small studies, ECV was not associated with uterine rupture in patients with previous cesarean or VBAC; however, repeat cesarean is generally a safe operation)

• Maternal obesity


Equipment and Supplies



• Intravenous catheter with heparin lock

• Blood-drawing equipment for a complete blood count and blood type and screen

• Syringe with 0.25 mg of terbutaline (Brethine)

• Fetal heart rate monitor

• Examination table with Trendelenburg’s position

• Ultrasonography machine

• Ultrasonic gel

• Towels

• Sterile gloves and lubricant (if vaginal examination is required)

• Syringe of Rh0 (D) immune globulin (RhoGAM) for Rh-negative patients


Preprocedure Patient Education


Usually the patient is examined and counseled in one clinic visit about risks, benefits, and alternatives to ECV (see the sample patient education form online at www.expertconsult.com) and returns for ECV at another visit. This delineation allows time for both the patient and her partner to make an informed decision about ECV. At the ECV visit, the patient should bring a signed consent form (see the sample patient education form online at www.expertconsult.com). The procedure should be scheduled as close to (but not before) 36 weeks’ gestational age as possible to maximize the chances of success while, it is hoped, avoiding a preterm birth. Before 36 weeks, although there is a high success rate for ECV, fetuses are more likely to spontaneously revert to breech. The patient should be instructed not to eat a heavy meal during the 3 hours before ECV. The clinician should also reassure the patient that ECV causes only minimal discomfort. The results of studies are mixed regarding use of conduction analgesia. Some studies show an increased success rate with epidural analgesia, whereas other studies showed no benefit with use of spinal analgesia. This has led the American College of Obstetricians and Gynecologists (2000) to conclude that there is insignificant evidence to recommend routine use of conduction analgesia with ECV.

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May 14, 2017 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on External Cephalic Version

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