CHAPTER 28: Breech Delivery

Near term, the fetus typically has spontaneously assumed a cephalic presentation. Conversely, if the fetal buttocks or legs enter the pelvis before the head, the presentation is breech. This fetal lie is more common remote from term, as earlier in pregnancy each fetal pole has similar bulk. At term, breech presentation persists in approximately 3 to 5 percent of singleton deliveries (Cammu, 2014; Lyons, 2015; Macharey, 2017).

The categories of frank, complete, and incomplete breech presentations differ in their varying relations between the lower extremities and buttocks. With a frank breech, lower extremities are flexed at the hips and extended at the knees, and thus the feet lie close to the head (Fig. 28-1). With a complete breech, both hips are flexed, and one or both knees are also flexed (Fig. 28-2). With an incomplete breech, one or both hips are extended. As a result, one or both feet or knees lie below the breech, such that a foot or knee is lowermost in the birth canal (Fig. 28-3). A footling breech is an incomplete breech with one or both feet below the breech.

Of term breech fetuses, the neck may be extremely hyperextended in perhaps 5 percent, and the term stargazing fetus is used (Cimmino, 1975). With these, fetal or uterine anomalies may be more prevalent and are sought if not previously identified (Phelan, 1983). With this hyperextension, vaginal delivery can result in injury to the cervical spinal cord. Thus, if identified at term, this is an indication for cesarean delivery (Westgren, 1981). That said, flexion itself may be implicated, as cases of spinal cord injury have been reported following uneventful cesarean delivery of such fetuses (Hernandez-Marti, 1984). With transverse lie and similar hyperextension of the fetal neck, the term flying fetus is applied.

Risk Factors

Understanding the clinical settings that predispose to breech presentation can aid early recognition. Other than early gestational age, risk factors include extremes of amnionic fluid volume, multifetal gestation, hydrocephaly, anencephaly, structural uterine abnormalities, placenta previa, pelvic tumors, and prior breech delivery. One study found that following one breech delivery, the recurrence rate for a second breech presentation was 10 percent, and for a subsequent third breech it was 28 percent (Ford, 2010).

Examination

Leopold maneuvers to ascertain fetal presentation are discussed in Chapter 22 (Diagnosis). With the first maneuver, the hard, round fetal head occupies the fundus. The second maneuver identifies the back to be on one side of the abdomen and the small parts on the other. With the third maneuver, if not engaged, the softer breech is movable above the pelvic inlet. After engagement, the fourth maneuver shows the breech to be beneath the symphysis. The accuracy of this palpation varies (Lydon-Rochelle, 1993; Nassar, 2006). Thus, with suspected breech presentation—or any presentation other than cephalic—sonographic evaluation is indicated.

During cervical examination with a frank breech, no feet are appreciated, but the fetal ischial tuberosities, sacrum, and anus are usually palpable. After further fetal descent, the external genitalia may also be distinguished. When labor is prolonged, the fetal buttocks may become markedly swollen, rendering digital differentiation of a face and breech difficult. In some cases, the anus may be mistaken for the mouth and the ischial tuberosities for the malar eminences. With careful examination, however, the finger encounters muscular resistance with the anus, whereas the hard, less yielding jaws are felt through the mouth. The finger, upon removal from the anus, may be stained with meconium. The mouth and malar eminences form a triangular shape, whereas the ischial tuberosities and anus lie in a straight line. With a complete breech, the feet may be felt alongside the buttocks. In footling presentations, one or both feet are inferior to the buttocks.

The fetal sacrum and its spinous processes are palpated to establish position. As with cephalic presentations, fetal position is designated to reflect the relations of the fetal sacrum to the maternal pelvis. Positions include left sacrum anterior (LSA), right sacrum anterior (RSA), left sacrum posterior (LSP), right sacrum posterior (RSP), and sacrum transverse (ST).

Multiple factors aid determination of the best delivery route for a given mother-fetus pair. These include fetal characteristics, maternal pelvic dimensions, coexistent pregnancy complications, provider experience, patient preference, hospital capabilities, and gestational age.

Compared with their term counterparts, preterm breech fetuses have distinct complications related to their small size and immaturity. For example, rates of head entrapment, birth trauma, and perinatal mortality can be greater. Accordingly, separate discussions of term and preterm breech fetuses are more appropriate.

Term Breech Fetus

Current obstetrical thinking regarding vaginal delivery of the term breech fetus has been tremendously influenced by results of the Term Breech Trial (Hannah, 2000). This trial included 1041 women randomly assigned to planned cesarean and 1042 to planned vaginal delivery. In the planned vaginal delivery group, 57 percent were actually delivered vaginally. Planned cesarean delivery was associated with a lower risk of perinatal mortality compared with planned vaginal delivery—3 per 1000 versus 13 per 1000. Cesarean delivery was also associated with a lower risk of “serious” neonatal morbidity—1.4 versus 3.8 percent. Short-term maternal morbidity was similar between groups.

Critics of the Term Breech Trial emphasize that fewer than 10 percent of candidates underwent radiological pelvimetry. Also, most of the outcomes included in the “serious” neonatal morbidity composite did not actually portend long-term infant disability (Whyte, 2004).

Since that trial, however, additional data favoring cesarean delivery has come from the World Health Organization (Lumbiganon, 2010). From their evaluation of more than 100,000 deliveries from nine participating Asian countries, they reported improved perinatal outcomes for the term breech fetus with planned cesarean compared with planned vaginal delivery. Other studies have evaluated neonatal outcome with cesarean delivery and also found lowered neonatal morbidity and mortality rates (Hartnack Tharin, 2011; Lyons, 2015; Rietberg, 2005; Vistad, 2015). From their metaanalysis, Berhan and Haileamlak (2016) calculate absolute risk of perinatal mortality to be 0.3 percent and of fetal birth trauma or neurological morbidity to be 0.7 percent.

In contrast, other studies support vaginal delivery as a suitable option at term (Hofmeyr, 2015a). The Presentation et Mode d’Accouchement—PREMODA study—which translates as presentation and mode of delivery—showed no differences in corrected neonatal mortality rates and neonatal outcomes according to delivery mode (Goffinet, 2006). This French prospective observational study involved more than 8000 women with term breech singletons. Strict criteria were used to select 2526 of these for planned vaginal delivery, and 71 percent of that group were delivered vaginally. Similarly, data from the Lille Breech Study Group in France showed no excessive morbidity in term breech singletons delivered vaginally provided strict fetal biometric and maternal pelvimetry parameters were applied (Michel, 2011). Other smaller studies support these findings as long as guidelines are part of the selection process (Alarab, 2004; Giuliani, 2002; Toivonen, 2012).

Long-term evidence in support of vaginal breech delivery comes from Eide and associates (2005). These investigators analyzed intelligence testing scores of more than 8000 men delivered breech and found no differences in intellectual performance in those undergoing vaginal or cesarean delivery. Also, a 2-year follow up from the Term Breech trial showed similar risks for death and for neurodevelopmental delay between delivery groups (Whyte, 2004).

Despite evidence on both sides of the debate, at least in the United States, rates of planned vaginal delivery attempts continue to decline. And as predicted, the number of skilled providers able to safely select and vaginally deliver breech fetuses continues to dwindle (Chinnock, 2007). Moreover, obvious medicolegal concerns make physician training in such deliveries difficult. In response, some institutions have developed birth simulators to improve resident competence in vaginal breech delivery (Deering, 2006; Maslovitz, 2007).

Preterm Breech Fetus

In contrast to the term breech fetus, there are no randomized trials regarding delivery of the preterm breech fetus. Moreover, study comparisons are often made difficult by lumping, splitting, or overlapping of preterm gestational age groups. All that said, it would appear that for the preterm breech fetus, planned cesarean delivery confers a survival advantage compared with planned vaginal delivery. Reddy and associates (2012) reported data from deliveries between 24 and 32 weeks’ gestation. For breech fetuses within these gestational ages, attempting vaginal delivery yielded a low success rate, and those completed were associated with higher neonatal mortality rates compared with planned cesarean delivery. Other investigations have reported similar findings (Bergenhenegouwen, 2014; Demirci, 2012; Muhuri, 2006).

For preterm fetuses in younger subgroups—23 to 28 weeks—the data are more conflicting, and some studies describe no improved survival rate with planned cesarean delivery (Bergenhenegouwen, 2015; Kayem, 2015; Thomas, 2016). For periviable fetuses, defined by them as 20 to 25^6/7 weeks, a consensus workshop of perinatal organizations concluded that “available data do not consistently support routine cesarean delivery to improve perinatal mortality or neurological outcomes for early preterm infants” (Raju, 2014). A subsequent joint statement by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine (2017) suggested consideration for cesarean delivery for periviable fetuses beginning at 23^0/7 weeks, with a recommendation for cesarean delivery at 25^0/7 weeks.

For more mature preterm breech fetuses, that is, between 32 and 37 weeks, again there are sparse data to guide delivery route selection. Bergenhenegouwen and coworkers (2015) studied more than 6800 breech deliveries in a subgroup between 32 and 37 weeks. With planned cesarean delivery, they found similar perinatal mortality rates but less composite mortality and severe morbidity. It appears in this subgroup that fetal weight rather than gestational age is likely more important. The Maternal-Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) states that vaginal breech delivery is reasonable when the estimated fetal weight is >2500 g (Kotaska, 2009). There are especial concerns for delivery of the second noncephalic-presenting twin fetus that are discussed in Chapter 45 (Evaluation of Fetal Presentation).

In the United States, all these findings shape practice, and cesarean delivery is almost uniformly favored for the preterm breech fetus for which resuscitation is planned.

Delivery Complications

Increased rates of maternal and perinatal morbidity can be anticipated with breech presentations. For the mother, with either cesarean or vaginal delivery, genital tract laceration can be problematic. With cesarean delivery, added stretching of the lower uterine segment by forceps or by a poorly molded fetal head can extend hysterotomy incisions. With vaginal delivery, especially with a thinned lower uterine segment, delivery of the aftercoming head through an incompletely dilated cervix or application of forceps may cause vaginal wall or cervical lacerations, and even uterine rupture. Manipulations may also extend an episiotomy, create deep perineal tears, and increase infection risks. Anesthesia sufficient to induce appreciable uterine relaxation during vaginal delivery may cause uterine atony and in turn postpartum hemorrhage. Maternal death is rare, but rates appear higher in those with planned cesarean delivery for breech presentation—a case fatality rate of 0.47 maternal deaths per 1000 births (Schutte, 2007). Last, the risks associated with vaginal breech delivery are balanced against general cesarean delivery risks described in Chapter 30 (Cesarean Delivery Risks). Long-term, cesarean risks include those associated with repeated hysterotomy or with vaginal birth after cesarean—VBAC—further described in Chapter 31 (Delivery Route Risks).

For the fetus, prematurity and its complications are frequently comorbid with breech presentation. Rates of congenital anomalies are also greater (Cammu, 2014; Mostello, 2014). Compared with cephalic presentation, umbilical cord prolapse is more frequent with breech fetuses (Behbehani, 2016; Obeidat, 2010). Birth trauma can include fractures of the humerus, clavicle, and femur (Canpolat, 2010; Matsubara, 2008). In some cases, traction may separate scapular, humeral, or femoral epiphyses (Lamrani, 2011). Trauma is more common with vaginal births, but fetal trauma is also seen with cesarean deliveries.

Rare traumatic injuries may involve soft tissues. Brachial plexus injury and paralysis is one example (Foad, 2008). The spinal cord may be injured or even severed, or vertebrae fractured, especially if great force is employed (Vialle, 2007). Hematomas of the sternocleidomastoid muscles occasionally develop after delivery but usually disappear spontaneously. Last, genital injury may follow breech delivery (Saroha, 2015).

Some perinatal outcomes may be inherent to the breech position rather than delivery. For example, development of hip dysplasia is more common in breech compared with cephalic presentation and is unaffected by delivery mode (de Hundt, 2012; Fox, 2010; Ortiz-Neira, 2012).

Imaging Techniques

In many fetuses—especially those that are preterm—the breech is smaller than the aftercoming head. Moreover, unlike cephalic presentations, the head of a breech-presenting fetus does not undergo appreciable molding during labor. Thus, if vaginal delivery is considered, fetal size, type of breech, and degree of neck flexion or extension are evaluated. In addition, pelvic dimensions are assessed to avoid head entrapment from cephalopelvic disproportion. Sonography and fetal pelvimetry are options.

Sonographic fetal evaluation will have been performed in most cases as part of prenatal care. If not, gross fetal abnormalities, such as hydrocephaly or anencephaly, can be rapidly ascertained with sonography. This will identify many fetuses not suitable for vaginal delivery. It will also help to ensure that a cesarean delivery is not performed under emergency conditions for an anomalous fetus with no chance of survival.

Head flexion can usually also be determined sonographically, and for vaginal delivery, the fetal head should not be extended (Fontenot, 1997; Rojansky, 1994). If imaging is uncertain, then simple two-view radiography of the maternal abdomen is useful to define fetal head inclination. Sonographic identification of a nuchal arm may warrant cesarean delivery to avoid neonatal harm (Sherer, 1989).

The accuracy of fetal weight estimation by sonography is not altered by breech presentation (McNamara, 2012). Although variable, many protocols use fetal weights >2500 g and <3800 to 4000 g or evidence of growth restriction as exclusion criteria for planned vaginal delivery (Azria, 2012; Kotaska, 2009). Similarly, a biparietal diameter (BPD) >90 to 100 mm is often considered exclusionary (Giuliani, 2002; Roman, 2008).

Pelvimetry assesses the maternal bony pelvis before vaginal delivery, and one-view computed tomography (CT), magnetic resonance (MR) imaging, or plain film radiography is suitable. Comparative data among these modalities for pelvimetry are lacking, but CT is favored due to its accuracy, low radiation dose, and widespread availability (Thomas, 1998). At Parkland Hospital, we use CT pelvimetry when possible to assess the critical dimensions of the pelvis (Chap. 2, Planes and Diameters of the Pelvis). Although variable, some suggest specific measurements to permit a planned vaginal delivery: inlet anteroposterior diameter ≥10.5 cm; inlet transverse diameter ≥12.0 cm; and midpelvic interspinous distance ≥10.0 cm (Azria, 2012; Vendittelli, 2006). Some have recommended maternal-fetal biometry correlation. Appropriate values include: the sum of the inlet obstetrical conjugate minus the fetal BPD is ≥15 mm; the inlet transverse diameter minus the BPD is ≥25 mm; and the midpelvis interspinous distance minus the BPD is ≥0 mm (Michel, 2011). With MR imaging, Hoffmann and colleagues (2016) found vaginal delivery success rates of 79 percent in selected candidates if the interspinous distance exceeded 11 cm.

Decision-Making Summary

Currently, the American College of Obstetricians and Gynecologists (2016b) recommends that “the decision regarding the mode of delivery should depend on the experience of the health-care provider” and that “planned vaginal delivery of a term singleton breech fetus may be reasonable under hospital-specific protocol guidelines.” These guidelines have been echoed by other obstetrical organizations (Kotaska, 2009; Royal College of Obstetricians and Gynaecologists, 2006). Risks versus benefits are weighed and discussed with the patient. If possible, this is preferably done before admission. A diligent search is made for other complications, actual or anticipated, that might warrant cesarean delivery. Common circumstances are listed in Table 28-1. For a favorable outcome with any breech delivery, at the very minimum, the birth canal must be sufficiently large to allow passage of the fetus without trauma. The cervix must be fully dilated, and if not, then a cesarean delivery nearly always is the more appropriate method of delivery if suspected fetal compromise develops.

Vaginal Delivery Methods

The conduct of both labor and delivery differ between cephalic and breech presentations. First, breech labor in general proceeds more slowly, but steady cervical progress is a positive indicator of adequate pelvic proportions (Lennox, 1998). Vaginal breech delivery is accomplished by one of three methods. With spontaneous breech delivery, the fetus is expelled entirely without any traction or manipulation other than support of the newborn. With partial breech extraction, the fetus is delivered spontaneously as far as the umbilicus, but the remainder of the body is delivered by provider traction and assisted maneuvers, with or without maternal expulsive efforts. With total breech extraction, the entire fetal body is extracted by the provider.

Labor Induction and Augmentation

As with many other aspects of breech position, induction or augmentation of labor is controversial. Here again, data are limited and mostly retrospective. With labor induction, Burgos and coworkers (2017) reported equivalent vaginal delivery rates compared with spontaneous labor. With induction, however, they reported higher rates of neonatal intensive care unit admission. But, others have found similar perinatal outcome and cesarean delivery rates (Jarniat, 2017; Marzouk, 2011). Finally, others described greater cesarean delivery rates with induction but similar neonatal outcomes (Macharey, 2016).

In many studies, successful vaginal delivery is associated with orderly labor progression. Thus, some protocols avoid augmentation for the breech-presenting fetus, whereas others recommend it only for hypotonic contractions (Alarab, 2004; Kotaska, 2009). In women with a viable fetus, at Parkland Hospital, we attempt amniotomy induction but prefer cesarean delivery instead of pharmacological labor induction or augmentation.

Labor Management

On arrival to the labor unit, surveillance of fetal heart rate and uterine contractions begins, and immediate recruitment of necessary staff includes: (1) a provider skilled in the art of breech extraction, (2) an associate to assist with the delivery, (3) anesthesia personnel who can ensure adequate analgesia or anesthesia when needed, and (4) an individual trained in newborn resuscitation. For the mother, intravenous access is obtained. This allows, if needed, emergency induction of anesthesia or maternal resuscitation following hemorrhage from lacerations or from uterine atony.

At admission, the status of the membranes and progression of labor are assessed. Knowledge regarding cervical dilatation, cervical effacement, and presenting part station is essential for preparation. If labor is too far advanced, pelvimetry may be unsafe if fetal expulsion in the radiology department is a possibility. This alone, however, should not force the decision for cesarean delivery. As mentioned, stepwise labor progression itself is a good indicator of pelvic adequacy (Biswas, 1993). Sonographic assessment, described earlier, is completed. Ultimately, the choice of abdominal or vaginal delivery is based on factors discussed earlier and listed in Table 28-1.

During labor, one-on-one nursing is ideal because of cord prolapse risks, and physicians must be readily available for such emergencies. Guidelines for monitoring the high-risk fetus are applied (Chap. 24, Intrapartum Surveillance of Uterine Activity). For first-stage labor, while most clinicians prefer continuous electronic monitoring, the fetal heart rate is recorded at a minimum of every 15 minutes. A scalp electrode can be safely affixed to the buttock, but genitalia are avoided. If a nonreassuring fetal heart rate pattern develops, then a decision must be made regarding the necessity of cesarean delivery.

When membranes rupture, either spontaneously or artificially, the cord prolapse risk is appreciable and is increased when the fetus is small or when the breech is not frank. Therefore, vaginal examination is performed immediately following rupture, and special attention is directed to the fetal heart rate for the first 5 to 10 minutes thereafter.

For women in labor with a breech presentation, continuous epidural analgesia is advocated by some. This may increase the need for labor augmentation and prolong second-stage labor (Chadha, 1992; Confino, 1985). These potential disadvantages are weighed against the advantages of better pain relief and increased pelvic relaxation should extensive manipulation be required. Analgesia must be sufficient for episiotomy, for breech extraction, and for Piper forceps application. Nitrous oxide plus oxygen inhalation can provide further relief from pain. If general anesthesia is required, it must be induced quickly.

Spontaneous Breech Delivery

Similar to vertex delivery, spontaneous expulsion of a breech fetus entails sequential cardinal movements. First, engagement and descent of the breech usually take place with the bitrochanteric diameter in one of the oblique pelvic diameters. The anterior hip usually descends more rapidly than the posterior hip, and when the resistance of the pelvic floor is met, internal rotation of 45 degrees usually follows, bringing the anterior hip toward the pubic arch and allowing the bitrochanteric diameter to occupy the anteroposterior diameter of the pelvic outlet. If the posterior extremity is prolapsed, however, it, rather than the anterior hip, rotates to the symphysis pubis.

After rotation, descent continues until the perineum is distended by the advancing breech, and the anterior hip appears at the vulva. By lateral flexion of the fetal body, the posterior hip then is forced over the perineum, which retracts over the fetal buttocks, thus allowing the fetus to straighten out when the anterior hip is born (Fig. 28-4). The legs and feet follow the breech and may be born spontaneously or require aid.

After the birth of the breech, there is slight external rotation, with the back turning anteriorly as the shoulders are brought into relation with one of the oblique diameters of the pelvis. The shoulders then descend rapidly and undergo internal rotation, with the bisacromial diameter occupying the anteroposterior plane. Immediately following the shoulders, the head, which is normally sharply flexed on the thorax, enters the pelvis in one of the oblique diameters and then rotates to bring the posterior portion of the neck under the symphysis pubis. The head is then born in flexion.

The breech may engage in the transverse diameter of the pelvis, with the sacrum directed anteriorly or posteriorly. The mechanism of labor in the transverse position differs only in that internal rotation is through an arc of 90 rather than 45 degrees. Infrequently, rotation renders the back of the fetus to lie posteriorly instead of anteriorly. Such rotation is prevented if possible. Although the head can be delivered by allowing the chin and face to pass beneath the symphysis, the slightest traction on the body may cause extension of the head, which increases the diameter of the head that must pass through the pelvis.

Partial Breech Extraction

With breech delivery, successively larger and less compressible parts are born. Thus, spontaneous expulsion is the exception, and vaginal delivery typically requires skilled provider participation for the fetus to navigate the birth canal. Noteworthy clinical pearls are provided by Yeomans (2017) in the third edition of Cunningham and Gilstrap’s Operative Obstetrics.

First, with all breech deliveries, unless the perineum is considerably lax, an episiotomy is made and is an important adjunct to delivery. As discussed in Chapter 27 (Episiotomy), mediolateral episiotomy may be preferred for its lower associated risk of anal sphincter lacerations. Ideally, the breech is allowed to deliver spontaneously to the umbilicus. Delivery of the breech draws the umbilicus and attached cord into the pelvis. Therefore, once the breech has passed beyond the vaginal introitus, the abdomen, thorax, arms, and head must be delivered promptly either spontaneously or assisted.

The posterior hip will deliver, usually from the 6 o’clock position, and often with sufficient pressure to evoke passage of thick meconium (see Fig. 28-4). The anterior hip then delivers, followed by external rotation to a sacrum anterior position. The mother is encouraged to continue to push as the fetus descends until the legs are accessible. The legs are sequentially delivered by splinting the femur with the operator’s fingers positioned parallel to the long axis of the femur, and by exerting pressure upward and laterally to sweep each leg away from the midline (Fig. 28-5).

Following delivery of the legs, the fetal bony pelvis is grasped with both hands. The fingers should rest on the anterior superior iliac crests and the thumbs on the sacrum. This minimizes the chance of fetal abdominal soft-tissue injury (Fig. 28-6). Maternal expulsive efforts are again used in conjunction with downward traction to affect delivery.

A cardinal rule in successful breech extraction is to employ steady, gentle, downward traction until the lower halves of the scapulas are delivered, making no attempt at delivery of the shoulders and arms until one axilla becomes visible. It makes little difference which shoulder is delivered first, and two methods are suitable for their delivery. In the first method, with the scapulas visible, the trunk is rotated either clockwise or counterclockwise to bring the anterior shoulder and arm into view (Fig. 28-7). During delivery of the arm, fingers and hand are aligned parallel to the humerus and act to splint and prevent humeral fracture. The body of the fetus is then rotated 180 degrees in the reverse direction to bring the other shoulder and arm into position for delivery.

The second method is employed if trunk rotation is unsuccessful. With this maneuver, the posterior shoulder is delivered first. For this, the feet are grasped in one hand and drawn upward over the inner thigh of the mother (Fig. 28-8). The hand enters over the shoulder, fingers are aligned parallel to the long axis of the humerus, and the fetal arm is swept upward. The posterior shoulder slides out over the perineal margin and is usually followed by the arm and hand. Then, by depressing the body of the fetus, the anterior shoulder emerges beneath the pubic arch, and the arm and hand usually follow spontaneously. After both shoulders are delivered, the back of the fetus tends to rotate spontaneously to the symphysis. Delivery of the head may then be accomplished.

Nuchal Arm

During delivery, one or both fetal arms occasionally may lie across the back of the neck and become impacted at the pelvic inlet. With such a nuchal arm, delivery is more difficult and can be aided by rotating the fetus through a half circle in such a direction that the friction exerted by the birth canal will draw the elbow toward the face (Fig. 28-9). With a right nuchal arm, the body should be rotated counterclockwise, which rotates the fetal back toward the maternal right. With a left nuchal arm, the rotation is clockwise. If rotation fails to free the nuchal arm, it may be necessary to push the fetus upward to a roomier part of the pelvis. If the rotation is still unsuccessful, the nuchal arm often is extracted by hooking a finger(s) over it and forcing the arm over the shoulder, and down the ventral surface for delivery of the arm. In this event, fracture of the humerus or clavicle is common.

Delivery of the Aftercoming Head

Mauriceau Maneuver

The fetal head is normally extracted with forceps or by one of several maneuvers. With any of these techniques, hyperextension of the fetal neck is avoided.

With the Mauriceau maneuver, the index and middle finger of one hand are applied over the maxilla, to flex the head, while the fetal body rests on the palm of the same hand and forearm (Fig. 28-10). Fetal legs straddle the forearm. Two fingers of the other hand then are hooked over the fetal neck and grasp the shoulders. Downward traction is concurrently applied until the suboccipital region appears under the symphysis. Gentle suprapubic pressure simultaneously applied by an assistant helps keep the head flexed. The body then is slightly elevated toward the maternal abdomen, and the mouth, nose, brow, and eventually the occiput emerge successively over the perineum. With this maneuver, the provider uses both hands simultaneously to exert continuous downward gentle traction while balancing forces between the fetal neck and maxilla to avoid neck hyperextension.

Forceps

Specialized forceps can be used to deliver the aftercoming head. Piper forceps, shown in Figure 28-11, or Laufe-Piper forceps may be applied electively or when the Mauriceau maneuver cannot be accomplished easily. The blades of the forceps are not applied to the aftercoming head until it has been brought into the pelvis by gentle traction, combined with suprapubic pressure, and is engaged. Suspension of the body of the fetus in a towel effectively holds the fetus up and helps keep the arms and cord out of the way as the forceps blades are applied.

Because the forceps blades are directed upward from the level of the perineum, some choose to apply them from a one-knee kneeling position. Piper forceps have a downward arch in the shank to accommodate the fetal body and lack a pelvic curve. This shape permits direct application of the cephalic curve of the blade along the length of the maternal vagina and fetal parietal bone. The blade to be placed on the maternal left is held in the provider’s left hand. The right hand slides between the fetal head and left maternal vaginal sidewall to guide the blade inward and around the parietal bone. The opposite blade mirrors this application.

Once in place, the blades are articulated, and the fetal body rests across the shanks. The head is delivered by pulling gently outward and slightly raising the handle simultaneously. This rolls the face over the perineum, while the occiput remains beneath the symphysis until after the brow delivers. Ideally, the head and body move in unison to minimize neck hyperextension.

Modified Prague Maneuver

Rarely, the back of the fetus fails to rotate to the symphysis. The fetus still may be delivered using the modified Prague maneuver. With this, two fingers of one hand grasp the shoulders of the back-down fetus from below while the other hand draws the feet up and over the maternal abdomen (Fig. 28-12).

Head Entrapment

This emergency reflects either an incompletely dilated cervix or cephalopelvic disproportion. First, especially with a small preterm fetus, an incompletely dilated cervix can constrict around the neck and impede delivery of the aftercoming head. At this point, significant cord compression must be assumed, and time management is essential. With gentle traction on the fetal body, the cervix, at times, may be manually slipped over the occiput. If unsuccessful, then Dührssen incisions may be necessary (Fig. 28-13). General anesthesia with halogenated agents or intravenous nitroglycerin is another option to aid lower uterine segment relaxation. As an extreme measure, replacement of the fetus higher into the vagina and uterus, followed by cesarean delivery, can rescue an entrapped breech fetus. This Zavanelli maneuver is classically performed to relieve intractable shoulder dystocia (Sandberg, 1988). However, case reports also have described its use for an entrapped aftercoming head (Sandberg, 1999; Steyn, 1994).

In cases with cephalopelvic disproportion and arrest of aftercoming head, the Zavanelli maneuver or symphysiotomy are options (Sunday-Adeoye, 2004; Wery, 2013). Using local analgesia, symphysiotomy surgically divides the intervening symphyseal cartilage and much of its ligamentous support to widen the symphysis pubis up to 2.5 cm (Basak, 2011). Lack of provider training and potentially serious maternal pelvic or urinary tract injury explain its rare use in the United States. That said, if cesarean delivery is not possible, symphysiotomy may be lifesaving for both mother and baby (Hofmeyr, 2012).

Total Breech Extraction

Complete or Incomplete Breech

At times, total extraction of a complete or incomplete breech may be required. A hand is introduced through the vagina, and both fetal feet are grasped. The ankles are held with the middle finger lying between them. With gentle traction, the feet are brought through the introitus (Fig. 28-14). As the legs begin to emerge through the vulva, downward gentle traction is continued. As the legs emerge, successively higher portions are grasped, first the calves and then the thighs. When the breech appears at the vaginal outlet, gentle traction is applied until the hips are delivered. The thumbs are then placed over the sacrum and the fingers over the iliac crests. Breech extraction is then completed, as described for partial breech extraction (Partial Breech Extraction).

If only one foot can be grasped, it can be brought down into the vagina and held with the appropriate hand, right hand for right foot and left hand for left foot (Yeomans, 2017). With the first foot secure, the opposite hand is introduced, passed upward along the leg, and guided to locate the other foot. If the remaining hip is extended, the second foot is usually easily grasped and brought down. If the hip is flexed and knee extended, a finger is hooked into that groin, and traction will bring the lower half of the fetus down until the leg can be reached. For cesarean delivery, these total breech extraction maneuvers can be used to deliver a complete, incomplete, or footling breech through the hysterotomy incision.

Frank Breech

During complete extraction of a frank breech, moderate traction is exerted by a finger in each groin and aided by a generous episiotomy. Once the breech is pulled through the introitus, the steps described for partial breech extraction are then completed (Partial Breech Extraction). These maneuvers are also used during cesarean delivery of a frank breech through a hysterotomy incision.

Rarely during vaginal delivery, a frank breech will require decomposition inside the uterine cavity. Attributed to Pinard (1889), this procedure converts a frank breech into a footling breech. It is accomplished more readily if the membranes have ruptured only recently. It becomes extremely difficult if amnionic fluid is scant and the uterus is tightly contracted around the fetus. Pharmacological relaxation by general anesthesia or intravenous magnesium sulfate, nitroglycerin, or a betamimetic agent may be required. To begin, two fingers are carried up along one leg to externally rotate the hip by pressing on the medial side of the thigh parallel to the femur. Simultaneously, pressure in the popliteal fossa should prompt spontaneous knee flexion, which brings the corresponding foot into contact with the back of the provider’s hand. The fetal foot then may be grasped and brought down.

With version, fetal presentation is altered by physically substituting one pole of a longitudinal presentation for the other, or converting an oblique or transverse lie into a longitudinal presentation. Manipulations performed through the abdominal wall that yield a cephalic presentation are termed external cephalic version. Manipulations accomplished inside the uterine cavity that yield a breech presentation are designated internal podalic version. This latter procedure is reserved for delivery of a second twin and described in Chapter 45 (Vaginal Birth after Cesarean Delivery).

Indications

External cephalic version (ECV) reduces the rate of noncephalic presentation at birth (Hofmeyr, 2015b). For breech fetuses near term, the American College of Obstetricians and Gynecologists (2016a,b) recommends that version be offered and attempted whenever possible. Its success rate averages about 60 percent (de Hundt, 2014). For women with a transverse lie, the overall success rate is significantly higher.

In general, ECV is attempted before labor in a woman who has reached 37 weeks’ gestation. Before this time, breech presentation still has a high likelihood of correcting spontaneously. And, if ECV is performed too early, time may allow a reversion back to breech (Bogner, 2012). Last, if attempts at version cause a need for immediate delivery, complications of iatrogenic late-preterm delivery generally are not severe.

Absolute contraindications to external version are few. It is contraindicated if vaginal delivery is not an option, such as with placenta previa. Another is multifetal gestation. Relative contraindications are early labor, oligohydramnios or rupture of membranes, known nuchal cord, structural uterine abnormalities, fetal-growth restriction, and prior abruption or its risks (Rosman, 2013). While many consider a prior cesarean delivery a contraindication, a few small studies found ECV was not associated with uterine rupture (Burgos, 2014; Keepanasseril, 2017; Weill, 2017). At Parkland Hospital, we do not attempt version in these women. More data from clinical studies are needed.

Several factors can improve the chances of a successful attempt. These include multiparity, unengaged presenting part, nonanterior placenta, nonobese patient, and abundant amnionic fluid (Kok, 2009, 2011; Velzel, 2015). To augment the last parameter, Burgos and coworkers (2014) administered a preprocedural 2-L intravenous fluid bolus. While this improved amnionic fluid volume, it did not increase version success rates.

Complications

Patient counseling includes a discussion regarding small but real risks for placental abruption, preterm labor, and fetal compromise. Rarely, uterine rupture, fetomaternal hemorrhage, alloimmunization, amnionic fluid embolism, and even death may also complicate attempts at external version. That said, fetal deaths are rare, serious complication rates are typically very low, and emergent cesarean rates are 0.5 percent or less (Grootscholten, 2008; Rodgers, 2017). And even after successful ECV, several reports suggest that the cesarean delivery rate does not completely revert to the baseline for vertex presentations. Specifically, dystocia, malpresentation, and nonreassuring fetal heart patterns may be more common in these fetuses completing successful version (Chan, 2004; de Hundt, 2014; Vézina, 2004).

Technique

ECV should be carried out in an area that has ready access to a facility equipped to perform emergency cesarean delivery (American College of Obstetricians and Gynecologists, 2016a). Because of the risk for surgical intervention, intravenous access is obtained, and patients abstain from eating for 6 or more hours. Sonographic examination is performed to confirm nonvertex presentation, document amnionic fluid volume adequacy, exclude obvious fetal anomalies if not done previously, and identify placental location and fetal spine orientation. Preprocedural external monitoring is performed to assess fetal heart rate reactivity. Anti-D immune globulin is given to Rh-D negative women. Tocolysis and regional analgesia may be elected, and rationale for these is provided in subsequent sections.

The woman is placed in left lateral tilt to aid uteroplacental perfusion, and Trendelenburg positioning helps during elevation of the breech. During the procedure, we prefer to monitor fetal heart motion sonographically. An abundant abdominal coating of ultrasound gel permits this and also minimizes painful skin friction (Vallikkannu, 2014).

A forward roll of the fetus usually is attempted first. One or two providers may participate, and one hand grasps the head. The fetal buttocks are then elevated from the maternal pelvis and displaced laterally (Fig. 28-15). The buttocks are then gently guided toward the fundus, while the head is simultaneously directed toward the pelvis. If the forward roll is unsuccessful, a backward flip is attempted. ECV attempts are discontinued for excessive discomfort, persistently abnormal fetal heart rate, or after multiple failed attempts. 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 multiparas.

If ECV is successful, a nonstress test is repeated until a normal test result is obtained. If version is completed before 39 weeks’ gestation, then awaiting spontaneous labor and fetal maturity is preferred. In some studies, immediate labor induction is linked to higher cesarean delivery rates (Burgos, 2015; Kuppens, 2013).

Tocolysis

To relax the uterus prior to an ECV attempt, existing evidence supports the use of tocolysis (American College of Obstetricians and Gynecologists, 2016a). Most data support the use of the beta-mimetics terbutaline and ritodrine (Cluver, 2015). In one such trial, Fernandez and coworkers (1996) reported that the success rate with subcutaneous terbutaline—52 percent—was significantly higher than without—27 percent. Our policy at Parkland Hospital is to administer 250 μg of terbutaline subcutaneously to most women before attempted ECV. When maternal tachycardia—a known side effect of terbutaline—is noted, the attempt is begun. Data are limited and, in some cases nonsupportive, for alternate agents that include calcium-channel blockers, such as nifedipine; nitric oxide donors, such as nitroglycerin; the oxytocin-receptor antagonist atosiban; and another betamimetic salbutamol (Burgos, 2010; Hilton, 2009; Kok, 2008; Vani, 2009; Velzel, 2017; Wilcox, 2011).

Conduction Analgesia

Epidural analgesia coupled with tocolysis has been reported to increase version success rates compared with tocolysis alone (Goetzinger, 2011; Magro-Malosso, 2016). Moreover, rates of complications that include fetal heart rate aberrations, emergency cesarean delivery, or placental abruption were not greater with regional analgesia. Of randomized trials, spinal and epidural have both shown success (Khaw, 2015; Weiniger, 2010). Currently, the superior technique and best drugs to administer are unclear. In contrast, from limited data, intravenous sedation does not appear to improve success rates (Burgos, 2016; Khaw, 2015).

Moxibustion

This is a traditional Chinese medicine technique that burns a cigarette-shaped stick of ground Artemisia vulgaris—which is also known as mugwort or in Japanese as moxa. At the BL 67 acupuncture point, the stick is directly placed against the skin or indirectly heats an acupuncture needle at the site to increase fetal movement and promote spontaneous breech version (Ewies, 2002). It is performed usually between 33 and 36 weeks’ gestation to permit a trial of ECV if not successful. Results from randomized controlled studies are conflicting (Bue, 2016; Coulon, 2014; Coyle, 2012; Sananes, 2016; Vas, 2013).