Version is a procedure in which the fetal presentation is altered by physical manipulation, either substituting one pole of a longitudinal presentation for the other, or converting an oblique or transverse lie into a longitudinal presentation. According to whether the head or breech is made the presenting part, the operation is designated cephalic or podalic version, respectively. In external version, the manipulations are performed exclusively through the abdominal wall. In internal version, they are accomplished inside the uterine cavity.
External Cephalic Version
In the United States, Van Dorsten and co-workers (1981) rekindled interest in this procedure, and the American College of Obstetricians and Gynecologists (2006) recommends that version should be offered and attempted whenever possible. The success rate for external version ranges from 35 to 86 percent, with an average of 58 percent (American College of Obstetricians and Gynecologists, 2000). In their review of 25 reports through 1991, Zhang and co-workers (1993) reported an average success rate of 65 percent. Moreover, they observed that after successful version, almost all fetuses remain cephalic.
Interestingly, several reports suggest that even after successful version, the risk of cesarean delivery does not completely revert to the institutional baseline for vertex presentations, and that dystocia, malpresentation, and nonreassuring fetal heart patterns may be more common after successful version (Chan and colleagues, 2004; Vézina and associates, 2004). Also, failure is not always absolute. Ben-Meir and colleagues (2007) reported a spontaneous version rate of 7 percent among 226 failed versions—2 percent among nulliparas and 13 percent among parous women.
In general, when a breech presentation is recognized prior to labor in a woman who has reached 36 weeks' gestation, external cephalic version should be considered. Before this time, there is a relatively high incidence of recurrence. After 36 weeks, however, the likelihood of spontaneous version is low (Hickok and colleagues, 1992; Westgren and co-workers, 1985). Moreover, if version results in the need for immediate delivery, complications of iatrogenic preterm delivery generally are not severe.
Version is contraindicated if vaginal delivery is not an option. Examples include placenta previa or nonreassuring fetal status. A prior uterine incision is a relative contraindication, although in small studies external version was not associated with uterine rupture in women who had previously undergone cesarean delivery (Abenhaim, 2009; Flamm, 1991; Sela, 2009, and all their associates). At the University of Alabama at Birmingham, decisions about version in women with a prior cesarean incision are individualized. At Parkland Hospital, external version is not attempted in these women. Obviously, larger studies are needed to better characterize risks versus benefits.
Factors Associated with Successful Version
A number of associated factors can improve or lessen the chances of a successful version attempt (Table 24-1). Increasing parity and increasing amnionic fluid index are consistent factors associated with success (Boucher, 2003; Hutton, 2008; Kok, 2008; Zhang, 1993, and all their co-workers). Kok and colleagues (2009) reported improved success also in those with a posterior placenta and complete breech position.
Table 24-1. Factors that May Modify the Success of External Cephalic Version |Favorite Table|Download (.pdf)
Table 24-1. Factors that May Modify the Success of External Cephalic Version
Ample amnionic fluid
Inability to palpate head
Fetal spine anterior or posterior
A number of factors are predictive of failed version. Lau and associates (1997) identified three: (1) an engaged presenting part, (2) difficult palpation of the fetal head, and (3) a uterus tense to palpation. When all three were present, there were no successes; with two, success was less than 20 percent; and if none was present, the success rate was 94 percent. In a secondary analysis of a randomized trial that included 178 women undergoing attempted version, Hutton and colleagues (2008) reported that an unengaged presenting part improved the success rate. They recommended consideration for attempted version before engagement, that is, earlier in pregnancy. Other reported determinants of failed version include maternal obesity, anterior placenta, cervical dilatation, and anterior or posterior positioning of the fetal spine (Fortunato and associates, 1988; Newman and colleagues, 1993).
Women with a transverse lie usually are excluded from analyses of breech version because the overall success rate approaches 90 percent (Newman and colleagues, 1993).
External cephalic version should be carried out in an area that has ready access to a facility equipped to perform emergency cesarean deliveries (American College of Obstetricians and Gynecologists, 2000). Sonographic examination is performed to confirm nonvertex presentation and adequacy of amnionic fluid volume, to exclude obvious fetal anomalies if not done previously, and to identify placental location. External monitoring is performed to assess fetal heart rate reactivity. Anti-D immune globulin is given if indicated.
A forward roll of the fetus usually is attempted first. As shown in Figure 24-18, each hand grasps one of the fetal poles, and the buttocks are elevated from the maternal pelvis and displaced laterally. The buttocks are then gently guided toward the fundus, while the head is directed toward the pelvis. If the forward roll is unsuccessful, then a backward flip is attempted. Version attempts are discontinued for excessive discomfort, persistently abnormal fetal heart rate, or after multiple failed attempts. The nonstress test is repeated after version until a normal test result is obtained.
External cephalic version. A. Clockwise pressure is exerted against the fetal poles. B. Successful completion is noted by feeling the head above the symphysis during Leopold examination.
Although many clinicians recommend uterine relaxation with a tocolytic agent, their impact on success is controversial. For example, Robertson and associates (1987) used ritodrine, Tan and colleagues (1989) used salbutamol, and Yanny and associates (2000) used glyceryl trinitrate, but none observed apparent benefits. Indeed, Bujold and colleagues (2003) conducted a placebo-controlled trial of 99 women and reported that sublingual nitroglycerin was associated with a lower version success rate than placebo—48 versus 63 percent. In another randomized trial, however, Fernandez and co-workers (1996) reported that the success rate with subcutaneous terbutaline-52 percent-was significantly higher than without—27 percent. Our policies at the University of Alabama at Birmingham and at Parkland Hospital are to administer 250 μg of terbutaline subcutaneously to most women prior to attempted version. When maternal tachycardia—a known side effect of terbutaline—is noted, then the version attempt is begun.
Epidural analgesia has been reported to increase the success of version. In a randomized trial, Schorr and co-workers (1997) found that epidural analgesia given with terbutaline tocolysis resulted in a 60-percent success rate compared with 30 percent of women given only terbutaline. In another randomized trial of 108 women, Mancuso and associates (2000) reported a success rate of 59 percent with epidural analgesia versus 33 percent without.
Spinal analgesia has also been used for external version. Weiniger and associates (2007) reported in a small trial of 70 women that spinal analgesia increased the success rate of version. In the trials of Dugoff (2001) and Delisle (2001) and their colleagues, it was not of benefit. According to the American College of Obstetricians and Gynecologists (2000), there is not enough consistent evidence to recommend conduction analgesia routinely for external version.
There are some unconventional interventions that have been used to help effect version. Cardini and Weixen (1998) performed a randomized trial to evaluate moxibustion. This involves burning the herbal preparation moxa to generate heat to stimulate acupuncture point BL67—to promote spontaneous breech version. Women in the intervention group experienced significantly increased fetal movements and more often had a cephalic presentation at delivery. These astounding results were not replicated in a follow-up study by Cardini and co-workers (2005). Mehl (1994) found hypnosis with suggestions for relaxation to be effective. Finally, Crawford (2005) described a case report of successful use of an old folk remedy—application of ice to the abdomen—to cause version.
Risks of external version include placental abruption, uterine rupture, fetomaternal hemorrhage, isoimmunization, preterm labor, fetal compromise, and even death. Most worrisome is the report by Stine and co-workers (1985) of a maternal death due to amnionic fluid embolism. That said, fetal deaths are rare (Zhang and colleagues, 1993).
With the exception of rare severe complications, based on a comprehensive review, Collaris and Oei (2004) concluded that external cephalic version is safe. One caveat was that complications were more common when conduction analgesia was used. Use of nitrous oxide or conduction analgesia was associated with twice as many abnormal fetal heart rate tracings. Moreover, vaginal bleeding and procedure-related emergency cesarean deliveries were increased tenfold. These reviewers concluded that diminished pain in these women likely encouraged overzealous application of force during the version attempts, which led to complications. More recently, Collins and associates (2007) report very low complication rates and an emergency cesarean rate of only 0.5 percent in 805 consecutive external cephalic version attempts at the John Radcliffe Hospital in Oxford, England.
This maneuver is used only for delivery of a second twin. It consists of the insertion of a hand into the uterine cavity to turn the fetus manually. The operator seizes one or both feet and draws them through the fully dilated cervix while using the other hand transabdominally to push the upper portion of the fetal body in the opposite direction as shown in Chapter 39, Internal Podalic Version. This is followed by breech extraction.