There is a higher risk for perinatal morbidity and mortality with breech presentation, even when the risk is adjusted for preterm gestation. The factors that cause breech presentation are often more important than the presentation itself. For example, hydrocephalus and anencephaly predispose to breech presentation and significantly contribute to neonatal morbidity and mortality. Relative perinatal mortality rates (calculated from data for linked siblings from the Medical Birth Registry of Norway) confirm that breech presentation is a marker of perinatal risk, regardless of the mode of delivery. Even after successful external cephalic version (ECV), women are at increased risk for cesarean delivery because of dystocia or an abnormal fetal heart rate (FHR) tracing, compared with women with natural cephalic presentation.

Vaginal breech delivery entails a higher risk for maternal morbidity (e.g., infection, perineal trauma, hemorrhage) than vertex delivery. However, among women with breech presentation, maternal outcomes are similar between women who have a planned cesarean delivery and those who have a trial of labor. At 2 years postpartum, maternal morbidity assessed by questionnaire (917 responses for a 79% response rate) did not differ for urinary incontinence, breastfeeding, pain, depression, menstrual problems, fatigue, and distressing memories of the birth experience. In a single-center study of 846 singleton breech deliveries, Schiff et al. did not find a higher risk for maternal morbidity in women who had intrapartum cesarean delivery compared with women who had elective cesarean delivery.

The process of ECV converts a breech or shoulder presentation to a vertex presentation by the application of pressure to the maternal abdomen to reposition the fetus. The average success rate for this procedure is 58%, with a wide range reported in published studies. ECV is most likely to be successful if (1) the presenting part has not entered the pelvis, (2) amniotic fluid volume is normal, (3) the fetal back is not positioned posteriorly, (4) the patient is not obese, (5) the patient is parous, and (6) the presentation is either frank breech or transverse. Early labor does not preclude successful ECV, but ECV is rarely successful when the cervix is fully dilated or when the membranes have ruptured. Multivariable predictive models may allow clinicians to improve prediction of successful ECV, with published models showing moderate discrimination and good calibration.

ECV should ideally occur between 37 and 39 weeks’ gestation for multiple reasons. First, spontaneous version to vertex presentation most often occurs by 37 weeks’ gestation. Second, successful performance of ECV after 37 weeks’ gestation decreases the likelihood of spontaneous reversion from vertex to breech presentation. Third, if complications occur during ECV performed after 37 weeks’ gestation, emergency delivery will not result in delivery of a preterm infant.

Successful ECV helps reduce the risk for perinatal morbidity and mortality associated with breech delivery. The American College of Obstetricians and Gynecologists (ACOG) has suggested that “because the risk of an adverse event occurring as a result of ECV is small and the cesarean birth rate is significantly lower among women who have undergone successful ECV, all women who are near term with breech presentations should be offered an ECV attempt if there are no contraindications.” There is no general consensus on eligibility for ECV, and contraindications vary among published guidelines. Labor and vaginal delivery occur in the majority of patients who undergo successful ECV, but anesthesia providers should remain vigilant because of the increased risk for intrapartum cesarean delivery necessitated by dystocia or a nonreassuring FHR tracing.

ECV is associated with a low rate of morbidity in contemporary obstetric practice, although placental abruption and preterm labor are potential complications. Safe ECV requires FHR monitoring and access to cesarean delivery services. In a systematic review of 84 studies that included 12,955 women, complications included transient (6.14%) and persistent (0.22%) FHR abnormalities, vaginal bleeding (0.30%), placental abruption (0.08%), emergency cesarean delivery (0.35%), and stillbirth (0.09%). Fetal-maternal hemorrhage is another potential complication of ECV. In one study, 16 of 89 (18%) patients undergoing ECV had Kleihauer-Betke stains indicating fetal-maternal hemorrhage.

The success of ECV is improved with the administration of a tocolytic agent (e.g., terbutaline or nitroglycerin) prior to the procedure. A randomized placebo-controlled trial found that the success rate of ECV doubled with use of terbutaline compared with placebo. A randomized controlled trial of intravenous nitroglycerin for tocolysis (100 to 300 µg bolus doses, up to a maximum total dose of 1000 µg) demonstrated a success rate of 24% in nulliparous women receiving nitroglycerin versus 8% in those receiving placebo. In parous women, the success rate was higher (43%) compared with nulliparous women and there was no difference between the nitroglycerin and placebo groups. Of interest, the rates of hypotension were similar between groups. A Cochrane review found that tocolysis with a beta-adrenergic receptor agonist prior to ECV increased the number of women with a cephalic presentation at the onset of labor (relative risk [RR], 1.68; 95% confidence interval [CI], 1.14 to 2.48) and reduced the number of cesarean deliveries (RR, 0.77; 95% CI, 0.67 to 0.88). Women with a prior cesarean delivery are also candidates for ECV, with studies showing similar rates of successful version compared with women without a prior cesarean delivery.

Another potential method to improve the success of ECV is neuraxial analgesia or anesthesia, likely via reducing maternal discomfort and relaxing abdominal wall musculature. Maternal discomfort can be significant during ECV, and greater pain during the procedure is associated with a lower chance of success. While historically some worried that anesthesia would facilitate the use of excessive force during the procedure and increase adverse perinatal events, these concerns are not supported by published evidence. In fact, spinal anesthesia reduces the force required for successful version.

Numerous studies now support the use of neuraxial analgesia for ECV. For example, Weiniger et al. randomly assigned 70 nulliparous women undergoing ECV to receive either spinal anesthesia with bupivacaine 7.5 mg or no anesthesia. The success rate was 67% in those who received spinal anesthesia, 32% in those without analgesia, and 42% in those who did not consent to enroll in the study; multivariable logistic regression modeling showed that the odds of successful ECV were 4.0-fold higher with spinal analgesia. A similar study in parous women by the same investigators also found an increased success rate with spinal anesthesia (87% versus 58%). A metaanalysis of nine trials that included 934 women found that, compared with control, neuraxial anesthesia increased the ECV success rate, increased the occurrence of cephalic presentation in labor, increased the vaginal delivery rate, decreased the cesarean delivery rate, and decreased maternal discomfort. There were no differences in the incidences of emergency cesarean delivery, transient fetal bradycardia, nonreassuring fetal testing, or placental abruption.

Additionally, several investigators have reported successful outcomes with neuraxial analgesia for ECV in women in whom a first attempt at ECV without neuraxial analgesia had been unsuccessful. Weiniger et al. found that failure of ECV was attributable to pain in 15 women in their control group, 11 of whom (73%) subsequently underwent successful ECV with spinal analgesia.

The optimal dose of intrathecal local anesthetic for ECV remains controversial. A metaanalysis of seven studies using neuraxial blockade to facilitate ECV concluded that administration of an anesthetic dose of local anesthetic doubles the success rate of ECV (RR, 1.95; 95% CI, 1.46 to 2.60), whereas an analgesic dose does not have any effect (RR, 1.18; 95% CI, 0.94 to 1.49). A subsequent prospective, randomized, blinded trial addressed the question of optimal intrathecal bupivacaine dose to facilitate ECV success. Patients were randomized to receive intrathecal bupivacaine doses of 2.5, 5, 7.5, or 10 mg with fentanyl 15 µg as part of a combined spinal-epidural (CSE) technique. Overall ECV success rate was 51.5% with no difference in success rates or cesarean delivery rates between the groups, demonstrating that intrathecal bupivacaine doses > 2.5 mg are not necessary and may only increase the incidence of hypotension. The obstetricians in that study did not perceive a difference in abdominal wall relaxation between the groups, even though pain scores were higher in the 2.5 mg bupivacaine group (median visual analog scale pain score 12 mm versus 4 to 5 mm in the other groups [scale 0 to 100 mm]). Patient satisfaction was high and not different between groups. Overall, optimal spinal local anesthetic dose likely varies according to the clinical situation. If the goal is timely discharge whether or not the ECV is successful, a lower spinal dose allows faster resolution of the block. If the patient will be admitted for delivery regardless of whether the version is successful, a higher dose will not affect the length of stay and could facilitate emergency cesarean delivery should that become necessary.

In contrast to neuraxial analgesia or anesthesia, the benefit of intravenous analgesia for ECV remains unclear. Khaw et al. randomized women with breech presentations to receive either spinal anesthesia with hyperbaric bupivacaine 9 mg plus fentanyl 15 µg, intravenous remifentanil infusion 0.1 µg/kg/min, or control (no anesthetic or analgesic intervention) before attempted ECV. On the first attempt, success rates were 83% in the spinal anesthesia group, 64% in the remifentanil group, and 64% in the control group. Cases in the control group who failed were rerandomized to spinal anesthesia or remifentanil for a second attempt, which resulted in success rates of 78% with spinal anesthesia versus 0% with remifentanil. There was no significant difference in the occurrence of fetal bradycardia requiring cesarean delivery. A recent systematic review of remifentanil’s effectiveness for ECV demonstrated a 43% increased chance of success compared with placebo (RR, 1.43; 95% CI, 1.14 to 1.78).

Overall, evidence suggests that neuraxial anesthesia helps to facilitate successful ECV and vaginal delivery and should therefore be used routinely. Intrathecal administration of 2.5 mg bupivacaine combined with fentanyl provides sufficient analgesia and abdominal wall relaxation while avoiding side effects such as hypotension associated with higher doses. Higher local anesthetic doses may be appropriate on a case-by-case basis.

Most parturients with a breech presentation now undergo cesarean delivery since the publication of the Term Breech Trial in 2000. In this trial, 2088 women with a singleton fetus in frank or complete breech presentation were enrolled from 26 countries and were randomly to undergo planned cesarean or planned vaginal delivery. While the study did not demonstrate any significant differences in maternal morbidity or mortality between groups during the delivery admission or the first 6 postpartum weeks, the finding of considerable differences in neonatal outcomes prompted important changes to contemporary obstetric practice, with nearly all planned breech deliveries now occurring via cesarean delivery. Using intention-to-treat analysis, the investigators demonstrated a lower rate of perinatal mortality, neonatal mortality, and serious neonatal morbidity in the planned cesarean delivery group (1.6% versus 5.0%, RR, 0.33 [95% CI, 0.19 to 0.56]). This difference was greatest in the 16 countries with a low perinatal mortality rate. The lowest risk for adverse perinatal outcomes occurred with prelabor cesarean delivery performed at term. The risk for adverse perinatal outcomes progressively increased with cesarean delivery performed during early labor, cesarean delivery performed during active labor, and vaginal birth. Labor augmentation and longer second stage of labor were associated with an increased risk for adverse perinatal outcomes, whereas the presence of an experienced clinician at delivery was associated with a reduced risk. A subsequent metaanalysis of 27 studies including 258,953 deliveries confirmed higher perinatal morbidity and mortality with planned vaginal breech delivery compared with planned cesarean delivery, although absolute risks were relatively low in both groups.

Despite the results of the Term Breech Trial, multicenter data from 2003 to 2011 showed an increase in vaginal delivery in Canadian women with breech presentation of nonanomalous singleton infants at term. The vaginal breech delivery rate increased from 2.7% to 3.9% over the studied time period, and the rate of cesarean breech delivery in labor increased from 8.7% to 9.8%. Composite neonatal morbidity and mortality rates, however, were significantly higher after vaginal delivery compared with cesarean delivery without labor, with an adjusted rate ratio of 3.6 (95% CI, 2.50 to 5.15). This difference was even more pronounced among women with a gestational age greater than 40 weeks (adjusted rate ratio 5.39; 95% CI, 2.68 to 10.80). Thus, the Canadian data support the results of the Term Breech Trial.

In many regions of the world, the number of planned vaginal breech deliveries has decreased because of the Term Breech Trial. For example, in Denmark, the proportion of singleton term breech infants delivered vaginally decreased abruptly from 20% before 1999 to 6% after 2001. At the same time, intrapartum or early neonatal mortality among all term breech infants decreased from 0.13% to 0.05% (RR, 0.38; 95% CI, 0.15 to 0.98). The downward trend in rates of vaginal breech delivery is likely to continue. As the number of practitioners with experience in performing vaginal breech delivery has decreased, the number of vaginal breech deliveries available to teach obstetric residents may no longer be adequate. Unintended results of this practice change include a generation of obstetricians who have lost the skills to practice vaginal breech deliveries and medicolegal concerns that now discourage the practice of vaginal breech delivery.

Nevertheless, obstetric providers in some regions of the world retain a strong tradition of offering vaginal breech delivery for selected patients. Published in 2006, the PREMODA (PREsentation et MODe d’Accouchement: presentation and mode of delivery) study described birth outcomes for all term breech deliveries in 12-month periods during 2001 to 2002 in 174 centers in France and Belgium. The study included 2526 women who planned vaginal breech delivery, of whom 1794 delivered vaginally, and 5579 women who planned cesarean breech delivery. The primary outcome captured a composite of fetal and neonatal mortality and serious morbidity and was not statistically different between women who planned to undergo vaginal delivery (1.60%; 95% CI, 1.14 to 2.17) and women who planned to undergo cesarean delivery (1.45%; 95% CI, 1.16 to 1.81), with odds ratio (OR) 1.10 (95% CI, 0.75 to 1.61). The authors suggested that rigorous adherence to protocols for patient selection, intrapartum fetal surveillance, and management of the second stage of labor contributed to improved outcomes for women attempting vaginal breech delivery.

Acknowledging the potential for acceptable patient outcomes with vaginal breech delivery in the setting of appropriate provider training and hospital resources, the ACOG makes the following recommendations about mode of singleton breech delivery at term :

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  “The decision regarding the mode of delivery should consider patient wishes and the experience of the healthcare provider.”

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  “Obstetrician-gynecologists and other obstetric care providers should offer ECV as an alternative to planned cesarean for a woman who has a term singleton breech fetus, desires a planned vaginal delivery of a vertex-presenting fetus, and has no contraindications. ECV should be attempted only in settings in which cesarean delivery services are readily available.”

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  “Planned vaginal delivery of a term singleton breech fetus may be reasonable under hospital-specific protocol guidelines for eligibility and labor management.”

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  “If a vaginal breech delivery is planned, a detailed informed consent should be documented—including risks that perinatal or neonatal mortality or short-term serious neonatal morbidity may be higher than if a cesarean delivery is planned.”

Owing to the concerns regarding adverse perinatal outcomes, planned vaginal breech delivery occurs uncommonly in most hospitals in North America and the United Kingdom ; however, vaginal breech delivery does occur, rarely, when patients present in advanced labor. In cases where vaginal breech delivery is considered, criteria listed in Box 34.2 may be used to determine appropriate patient eligibility. Personnel experienced in obstetric anesthesia and neonatal resuscitation are prerequisites for a trial of breech labor. Hyperextension of the fetal head remains an absolute contraindication to a trial of labor in the patient with a breech presentation. Many obstetric providers delay maternal expulsive efforts for 30 minutes after full cervical dilation. Others delay expulsive efforts until the breech is at the perineum.

There are three techniques for vaginal breech delivery. Spontaneous breech delivery avoids any traction or manipulation other than support of the infant’s body. With assisted breech delivery (also known as partial breech extraction), the infant is delivered spontaneously as far as the umbilicus; at that time, the obstetric provider assists delivery of the chest and the aftercoming head. With total breech extraction , the obstetric provider applies traction on the feet and ankles to deliver the entire body of the infant. Except for vaginal delivery of a second twin, obstetric providers almost never perform total breech extraction. Total breech extraction increases the likelihood of difficult, traumatic delivery, including entrapment of the fetal head. During assisted breech delivery or total breech extraction, the obstetric provider attempts to maintain flexion of the cervical spine during delivery of the head. This may be accomplished manually or by the application of Piper forceps ( Figs. 34.3 to 34.5 ). The obstetric provider commonly performs a generous episiotomy to prevent perineal obstruction of the aftercoming head.

Vaginal Breech Delivery. The black arrow indicates the direction of pressure from two fingers of the operator’s right hand on the fetal maxilla (not the mandible). This maneuver assists in maintaining appropriate flexion of the fetal vertex (direction of blue arrow) , as does moderate suprapubic pressure from an assistant. Delivery of the head may be accomplished with continued maternal expulsive forces and gentle downward traction.

From Barth WH. Malpresentations. In: Landon MB, Galan HL, Jauniaux ERM, et al., eds. Gabbe’s Obstetrics: Normal and Problem Pregnancies . 8th ed. Elsevier; 2021:319–342.

Vaginal Breech Delivery. Demonstration of incorrect assistance during the application of Piper forceps; the assistant hyperextends the fetal neck. Such positioning increases the risk for neurologic injury.

From Barth WH. Malpresentations. In: Landon MB, Galan HL, Jauniaux ERM, et al., eds. Gabbe’s Obstetrics: Normal and Problem Pregnancies . 8th ed. Elsevier; 2021:319–342.

Vaginal Breech Delivery. Once the Piper forceps are applied, the fetal trunk is supported by one hand, and gentle traction on the forceps (arrow) in the direction of the pelvic axis results in a controlled delivery.

From Barth WH. Malpresentations. In: Landon MB, Galan HL, Jauniaux ERM, et al., eds. Gabbe’s Obstetrics: Normal and Problem Pregnancies . 8th ed. Elsevier; 2021:319–342.

For patients with persistent breech presentation at term, elective cesarean delivery should be offered between 39 and 41 weeks’ gestation. Cesarean delivery at or near 39 weeks’ gestation reduces perinatal mortality not only through avoiding the risks of vaginal breech birth, but also by avoiding stillbirth after 39 weeks’ gestation and intrapartum risks should labor begin spontaneously before scheduled cesarean delivery. Obstetric providers should confirm breech presentation via ultrasonographic examination immediately prior to surgery to ensure spontaneous version has not occurred. Generous skin and uterine incisions should be made based on estimated fetal size, to minimize the likelihood of traumatic delivery. In preterm deliveries, a vertical uterine incision may need to be performed if the lower uterine segment is poorly developed. When such incisions extend to the body of the uterus (classical uterine incision), this confers a 1% to 12% risk for uterine rupture in subsequent pregnancies (see Chapter 20 ).

Benefits of neuraxial analgesia during breech labor include (1) pain relief, (2) inhibition of early pushing by blocking the perineal reflex, (3) ability of the parturient to push during the second stage and spontaneously deliver the infant to the level of the umbilicus, (4) a relaxed pelvic floor and perineum at delivery, and (5) the option to extend analgesia to surgical anesthesia for emergency cesarean delivery if needed.

Emergency cesarean delivery may be required at any time during a trial of labor. Both epidural and CSE analgesia are excellent choices during a trial of labor in patients with a breech presentation. These patients often have earlier complaints of rectal pressure than patients with a vertex presentation. It is important to provide sufficient sacral analgesia to inhibit pushing during the first stage of labor, which could result in expulsion of a fetal lower extremity through the partially dilated cervix, leading to umbilical cord prolapse or fetal head entrapment. A bolus dose of local anesthetic solution that includes a lipid-soluble opioid (e.g., fentanyl, sufentanil) may be required to block the sacral segments and the reflex urge to push during the late first stage of labor. Use of a local anesthetic alone to eliminate low back and perineal discomfort may result in extensive motor blockade, which may decrease the effectiveness of maternal expulsive efforts during the second stage.

Spinal, epidural, or general anesthesia can be administered for breech cesarean delivery. Because breech delivery can be more challenging than delivery of a vertex fetus, even during cesarean birth, uterine relaxation may be required. Certain fetal malformations, such as sacral teratoma or hydrocephalus, can present additional challenges to fetal extraction. When general anesthesia is used, the anesthesia provider can increase the concentration of volatile halogenated agent to facilitate uterine relaxation. When neuraxial anesthesia is used, intravenous or sublingual administration of nitroglycerin or intravenous administration of a beta-2-adrenergic receptor agonist such as terbutaline typically provides adequate uterine relaxation. It is rarely necessary to perform intraoperative induction of general anesthesia followed by administration of a high concentration of a volatile halogenated agent to facilitate delivery.

Regardless of the route of delivery, newborn infants with a breech presentation are typically born more depressed than infants with a vertex presentation. An individual skilled in neonatal resuscitation should be immediately available.