Just more than 15 years have elapsed since the publication of the Term Breech Trial. This is the largest randomized trial to compare planned vaginal and planned cesarean delivery for women carrying breech fetuses at term (Hannah, 2000). This monumental effort involved 121 centers in 26 countries. Its results provide many of the core tenets that shape current delivery practices. The authors interpreted their findings to indicate that planned cesarean delivery was the safest method to minimize neonatal morbidity and mortality rates. A secondary conclusion showed no difference in maternal morbidity rates between the two delivery routes. Obviously, they did not consider an abdominal incision and hysterotomy to be a morbid outcome.

The intent of this chapter is not to heap criticism on the conduct or interpretation of the Term Breech Trial—indeed, this has been done by others (Glezerman, 2006; Hauth, 2002; Keirse, 2002; Kotaska, 2004). But still, not all breech-presenting fetuses warrant cesarean delivery. Highly satisfactory outcomes of vaginal breech delivery have been documented at several centers since the Term Breech Trial. That said, achieving an atraumatic vaginal breech delivery for the fetus and the mother, in appropriately selected cases, requires knowledge, skill, and judgment on the part of the attendant. In this chapter, we present a conservative protocol to assist in selecting candidates for vaginal delivery of the term breech fetus and to emphasize the technical aspects of delivery that should optimize outcome.

Most reports of vaginal breech delivery focus on selection criteria and outcomes. Very little, if any, discussion of technique is provided. A review of 100 years of obstetric manuscripts and textbooks yields disparate views on what constituted proper technique for vaginal breech delivery (Yeomans, 2012). The approach presented here reflects this academic review and many combined years of clinical practice. At the same time, however, there is room for disagreement at almost every point of technique.

Even if the reader does not plan to offer vaginal breech delivery in his or her practice, many technical descriptions are relevant for cesarean delivery of the breech-presenting fetus. Moreover, it is undeniable that some women with a breech fetus may present with labor so advanced that it precludes cesarean delivery (Gilstrap, 2002). Others may refuse cesarean delivery, and in some low-resource settings, the option of cesarean delivery may not be readily available. Thus, the ability to safely deliver the breech fetus is an essential obstetric skill.

For the breech-presenting fetus, maternal morbidity and mortality rates are lower with vaginal birth compared with cesarean delivery. The converse is true for the fetuses, who experience higher morbidity and mortality rates compared with their vertex counterparts. Two of the leading contributors to that increase are prematurity and congenital malformations. Therefore, the degree to which mode of delivery increases morbidity and mortality rates is a key question. As noted, not all breeches require cesarean delivery. A much stronger case can be made that not all breeches are candidates for vaginal delivery.

Thus, a balance between maternal and fetal outcomes must exist and is guided by evidence-based data and clinical expertise. Virtually every article that endorses vaginal breech delivery as a safe option similarly stresses the requirement that an experienced provider must be present as either the primary operator or the senior supervisor. Unfortunately, the pendulum has swung so far in the direction of planned cesarean delivery that currently most training programs provide insufficient caseloads to ensure that today’s graduates will ever be certified as “experienced providers.” As described in Chapter 6, simulation training may help teach the steps of emergency vaginal breech delivery. However, the ability of simulation to fulfill credentialing requirements is doubtful.

A single-author report by Graves and colleagues (1980) illustrates how that pendulum began to swing 20 years before publication of the Term Breech Trial. One four-person practice accumulated 141 singleton vaginal breech deliveries in 20 years. In the first 10 years, the cesarean delivery rate was 5 percent, but in the final 5 years, the rate had increased to 71 percent. Seven of eight perinatal deaths were in the 103 women undergoing vaginal delivery. Of these seven, three fetuses weighed <1000 g, three had congenital anomalies, and one footling breech weighed 1250 g. These results confirm the previous statement regarding the importance of prematurity and congenital malformations as causes of perinatal mortality. Every member of Dr. Graves’ group was well trained in vaginal breech delivery, but the impressive evolution in mode of delivery selection during the two decades merely foreshadowed national trends. By the time randomization for the Term Breech Trial was initiated, the cesarean delivery rate for breech presentation in the United States already exceeded 80 percent. This again echoes concerns regarding the availability of providers experienced in vaginal breech delivery.

Breech Fetus Rates

The frequency of breech presentation at term is 3 to 4 percent. Of these fetuses, approximately 65 percent are frank, 5 percent are complete, and 30 percent are incomplete (Graves, 1980). Breech presentation is more common in preterm fetuses and is roughly inversely proportional to gestational age. In preterm fetuses, the proportions of frank and incomplete are reversed (Seeds, 1982). Older studies found a 5-percent incidence of hyperextended head among term breech fetuses. Because of their appearance on radiographs, the colloquial terms flying fetus or stargazing fetus were coined. This finding warrants cesarean delivery because of a significant risk for cervical spine injury with vaginal birth (Caterini, 1975).

Neonatal Morbidity

More than 45 years ago, at a time when many vaginal breech deliveries were still being performed, a group of investigators at the University of Michigan reported on the frequency and mechanisms of fetal trauma during vaginal breech delivery (Tank, 1971). They concluded that certain injuries resulted from manipulations used to aid delivery. In order of frequency from highest to lowest, the organs injured were brain, spinal cord, liver, adrenal glands, and spleen. Other injuries involved are shown in Table 21-1. Important lessons regarding technique of vaginal breech delivery can be learned from this list and are highlighted in the section on technique (p. 339). Of note, the composite outcome for neonatal morbidity used in the Term Breech Trial included several outcomes not directly related to trauma or technique (Table 21-2). Some of these morbidities are likely transient and not indicative of long-term outcome. In fact, in the 2-year follow-up study of infants from the Term Breech Trial, planned vaginal delivery was not associated with a greater risk of infant death or neurodevelopmental delay compared with planned cesarean delivery (Whyte, 2004). In each group of this trial, there was only one death beyond 28 days of life. There were 13 children with neurodevelopmental delay from the planned cesarean delivery group compared with only seven from the planned vaginal delivery group.

Maternal Morbidity

Following publication of the Term Breech Trial, the cesarean delivery rate in The Netherlands for term singleton breeches increased from 57 percent in 2000 to 81 percent in 2001 (Schutte, 2007). Four mothers died after elective cesarean delivery for breech presentation between 2000 and 2002. This yields a case fatality rate of 0.47 per 1000 operations. Two women died from pulmonary embolism, which more commonly follows cesarean delivery than vaginal birth. Two other women died of sepsis, also seen more often after cesarean delivery. Moreover, for the 547 nulliparas who underwent planned cesarean delivery in the Term Breech Trial, the likelihood that their subsequent deliveries would be repeat cesarean was greater (Hannah, 2000). As a correlate and described in Chapter 25 (p. 415), the rates of adjacent organ injury, placenta previa, placenta accreta, and cesarean hysterectomy all rise with the number of repeat cesarean deliveries. Clearly, maternal outcome deserves consideration in selecting the route of delivery for breech fetuses at term.

Selection Overview

For clinicians who offer women the opportunity for planned vaginal breech delivery, many published protocols assist in choosing appropriate candidates. These protocols all share the same two objectives, namely, maximize the likelihood of vaginal delivery and minimize fetal risk. One elaborate template is provided by the Society of Obstetricians and Gynecologists of Canada (Kotaska, 2009). On close examination, their approach is conservative for some recommendations and liberal for others. As a conservative example, induction of labor, even in an otherwise qualified candidate, is not recommended. But more liberally, radiologic pelvimetry is not considered necessary for a safe trial of labor. Table 21-3 has some prerequisites that many find reasonable. Notably, each criterion has acceptable alternatives, which allow practice to be individualized for a given clinical setting.

Factors that support a successful vaginal breech delivery should be enumerated. One equation for this calls attention to the difference between selection criteria and the conduct of labor and delivery (Yeomans, 2012):

With this, the attempted vaginal breech delivery (VBD) rate is highly variable, as shown in Table 21-4, and it is near zero in many centers in the United States. In centers that evaluate breech presentations for possible planned vaginal delivery, the attempted VBD rate will depend on the liberalness or restrictiveness of their selection criteria. The successful vaginal breech delivery rate shows less variability. It is affected to a greater degree by labor management, interpretation of fetal heart rate tracings, conduct of second-stage labor, and willingness to perform maneuvers such as traction in the groin, Pinard maneuver, and total breech extraction. Note that in Table 21-4, not all single-center studies clarify whether the category of cesarean delivery before labor applied to both indicated and purely elective cesarean deliveries. That is, it is unclear whether women assigned to the planned cesarean delivery group were suitable candidates for vaginal delivery but chose not to attempt vaginal birth or whether cesarean delivery was performed for recognized indications. Some of the latter include prior cesarean delivery, incomplete breech presentation, or suspected macrosomia, to name a few. This question of elective or indicated was eliminated by the randomized design of the Term Breech Trial.

Specific Criteria

Many of the prerequisites listed in Table 21-3 can be debated. Of these, the practice of obtaining adequate pelvic measurements by radiographic pelvimetry is the most contested. Some rely solely on clinical pelvimetry, supplemented by the observation of good progress in labor. In a study from France, one of the few remaining countries still advocating vaginal breech delivery, more than 80 percent of women selected for vaginal delivery had radiographic pelvimetry (Goffinet, 2006). In contrast, Canadian guidelines state that radiographic pelvimetry is not necessary (Kotaska, 2009).

If radiographic pelvimetry is employed, computed tomography (CT) is the preferred technique. From a study by Collea and coworkers (1980), minimum measurements are an anteroposterior (AP) inlet of 11 cm; transverse inlet of 11.5 cm; AP midplane of 11.5 cm; and transverse midplane of 10 cm. A review of these planes is found in Chapter 3 (p. 45). Other investigators have used slightly different thresholds or have combined pelvimetry with sonographic measurements of the biparietal diameter (Azria, 2012; Christian, 1990; Michel, 2011). For a more complete discussion of clinical pelvimetry, the reader is referred to Yeomans (2006).

If the pelvis is clinically adequate and the fetus is appropriately sized, some women will still develop dystocia due to inadequate contraction force. In this circumstance, labor augmentation with oxytocin is considered acceptable by some. In other obstetric units in the United States, oxytocin is not employed for this indication.

The lower and upper limits of estimated fetal weight are also controversial. Collea and coworkers (1980) used a lower limit of 2500 g. Albrechtsen and associates (1997) used an upper threshold of 4500 g. The lower limit strives to exclude growth-restricted and preterm fetuses. The upper threshold aims to avert fetopelvic disproportion (Kotaska, 2009). Our suggested limits are listed in Table 21-3.

Almost all protocols for planned vaginal breech delivery mandate that the breech configuration be either frank or complete. An exception is the report by Borbolla Foster and colleagues (2014) in which footling breech delivery was considered acceptable. The main concern with an incomplete or with a footling breech is the greater risk of associated cord prolapse in labor. However, in some cases, a woman will present at complete dilation with membranes either intact or ruptured and with feet in the vagina or outside the introitus. Vaginal delivery may be appropriate in this circumstance and may require total breech extraction.

The last two criteria from Table 21-3, experienced operator and patient consent, may ultimately exclude more planned vaginal breech deliveries than all the rest combined. Chinnock and Robson (2007) presented data from a survey showing that only 11 percent of final-year trainees in Australia planned to offer vaginal breech delivery to their patients. As for patient consent, decision making depends in large part on the manner in which evidence-based information is presented. It is appropriate to stress the negative maternal consequences that a first cesarean delivery poses to the maternal reproductive future. For women who meet selection criteria, this allows decisions to be based on both potential maternal and neonatal outcomes.

Once a candidate for vaginal breech delivery has been selected, then spontaneous labor is usually awaited, however, in some centers labor is induced. External version is another option to address breech presentation and is discussed on page 347. During the course of a trial of labor for a breech-presenting term fetus, indicated cesarean delivery is ultimately necessary in 20 to 50 percent of cases. This broad range illustrates that elements of skilled labor management must be considered. Namely, the two leading reasons that lead to intrapartum cesarean delivery of a well-selected breech are fetal distress and dystocia.

Regarding the first instance, electronic fetal monitoring is recommended throughout labor. Importantly, many category II tracings can be tolerated without immediate operative intervention, provided that moderate beat-to-beat variability is maintained.

In the second instance, and discussed earlier, in the absence of dystocia, oxytocin augmentation is acceptable (Kotaska, 2009). Prohibiting oxytocin use for either induction or augmentation will limit the rate of successful vaginal breech delivery (Alarab, 2004).

Intrapartum consultation with anesthesia staff is recommended. Epidural analgesia has advantages, especially during the manipulation needed for delivery of the fetal legs, arms, and head. Early epidural placement is reasonable to accommodate possible rapid labor progression or urgent cesarean delivery.

With a vertex presentation, engagement is defined by passage of the fetal biparietal diameter through the pelvic inlet. With a breech presentation, engagement takes place as the bitrochanteric diameter passes through the inlet. Measured along the long axis of the fetus, the distance from the buttocks to fetal bitrochanteric diameter is shorter than the distance from the vertex to the biparietal diameter in cephalic presenting fetuses. For this reason, engagement of the breech can be confidently assumed when the buttocks are palpated at the level of the ischial spines. At or beyond this time, prolapse of the umbilical cord is distinctly uncommon with frank or complete breeches.

This is a period that requires both vigilance and experience as the breech descends deep into the pelvis. Both Kotaska (2009) and Goffinet (2006) and their colleagues recommend a passive second stage of labor with no active pushing once a completely dilated cervix is identified. They allow this passive phase to last for 60 to 90 minutes. Once active pushing begins, its duration is limited to no more than 60 minutes, unless delivery is imminent.

Vaginal breech delivery should be performed in an operating room with equipment and personnel ready for immediate cesarean delivery should the need arise. One method is to use candy-cane stirrups attached to a metal operating table for vaginal breech delivery. Compared with booted support stirrups, these often abduct the thighs to a greater degree to provided needed vaginal access and manipulation space. Typically, epidural analgesia is already in place, but anesthesia personnel should be present, as should an experienced neonatal resuscitation team.

During the normal cardinal movements for vaginal breech delivery, internal rotation will align the fetal bitrochanteric diameter with the anteroposterior diameter of the maternal pelvis. In this position, the fetal back faces left or right. The corresponding positions would be designated left or right sacrum transverse (LST or RST), respectively.

With continued fetal descent, the anterior hip will appear first, but the posterior hip will deliver first, barring any operator interference. With normal cardinal movements, the dorsum will rotate anteriorly. If this does not occur spontaneously, the operator should intervene to complete this rotation.

Partial Breech Extraction

Of all breeches that are selected for planned vaginal delivery, those that have hips flexed and legs extended, that is, frank breeches, are by far the most common. Although still a remote possibility, cord prolapse is unlikely because the breech occludes the pelvis almost as effectively as the vertex.

By the time most frank breeches have descended to the pelvic floor, the bituberous diameter is either anteroposterior or in a left- or right-oblique relationship to the maternal pelvis. Some recommend episiotomy as an important adjunct to any vaginal breech delivery (Cunningham, 2014). However, vaginally parous women with a relaxed introitus and a small-to-average sized fetus are unlikely to benefit from an episiotomy. Thus, some reserve episiotomy for certain situations that include nulliparity, a tight introitus, or a relatively large fetus (Table 21-5). The largest diameter of the breech can be permitted to nearly fill the introitus with maternal expulsive effort before the decision is made for performing an episiotomy. Right-handed operators should almost always opt for a right mediolateral episiotomy. Merits to mediolateral versus midline episiotomy are outlined in Chapter 20 (p. 323). A sufficient incision depth of more than 1 inch allows for spontaneous delivery of the buttocks with just a few pushes. Importantly, blood loss can be appreciable if the episiotomy is cut too soon (Moir, 1971).