Breech Presentation

Breech presentation occurs in 3-4% of all deliveries. The occurrence of breech presentation decreases with advancing gestational age. Breech presentation occurs in 25% of births that occur before 28 weeks?gestation, in 7% of births that occur at 32 weeks, and 1-3% of births that occur at term.

Predisposing factors for breech presentation include prematurity, uterine abnormalities (eg, malformations, fibroids), fetal abnormalities (eg, CNS malformations, neck masses, aneuploidy), and multiple gestations. Abnormalities are observed in 17% of preterm deliveries that have breech presentation and in 9% of term gestations with breech presentation.

Perinatal mortality is increased 2- to 4-fold with breech presentation, regardless of the mode of delivery. Deaths most often are associated with malformations, prematurity, and intrauterine fetal demise.

Types of breeches

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• Frank breech (50-70%) - Hips flexed, knees extended ("pike")

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• Complete breech (5-10%) - Hips flexed, knees flexed ("cannonball")

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• Footling or incomplete (10-30%) - One or both hips extended, foot presenting

Historical considerations

Vaginal breech deliveries previously were the norm until 1959 when Wright proposed that all breech presentations should be delivered abdominally to reduce perinatal morbidity and mortality.

Vaginal breech delivery

Three types of vaginal breech deliveries are described, as follows:

Spontaneous breech delivery: No traction or manipulation of the infant is employed. This occurs predominantly in very preterm deliveries.

Assisted breech delivery: This is the most common type of vaginal breech delivery. The infant is allowed to spontaneously deliver up to the umbilicus, and then maneuvers are initiated to assist in the delivery of the remainder of the body, arms, and head.

The rate of cesarean delivery for breech presentation in the United States was 14% in 1970 and 86% in 1986. It currently is 90-95%. Breeches account for 10-15% of all cesarean deliveries. Green compared perinatal outcome for term breeches prior to 1975 (595 infants, cesarean delivery rate for breeches 22%) to 1978-1979 (164 infants, cesarean delivery rate 94%). Despite the increase in rates of cesarean delivery, no significant differences existed in rates of asphyxia, birth injury, or perinatal deaths.

Maneuvers for delivery are similar for vaginal breech delivery (eg, Pinard maneuver, ie, wrapping the hips with a towel for traction, head flexion during traction, rotation and sweeping out of arms; Mauriceau-Smellie-Veit maneuver).

An entrapped head still can occur during cesarean delivery if the uterus contracts down after delivery of the body, even with an adequate-appearing lower uterine segment. Entrapped heads occur more commonly with preterm breeches, especially with a low transverse uterine incision. Many authors advocate low vertical uterine incisions for the preterm breech. Low vertical incisions usually require extension into the corpus, resulting in cesarean delivery with all future deliveries.

Only 3 randomized studies have evaluated mode of delivery of the term breech. All other studies were nonrandomized or retrospective. Nonrandomized studies are subject to selection bias.

Collea et al randomized 208 laboring women with frank breech presentations at term to either attempted vaginal delivery after x-ray pelvimetry versus elective cesarean delivery. Oxytocin was allowed for dysfunctional labor. Of the 60 women with adequate pelves, 49 delivered vaginally. Two infants had transient brachial plexus injuries. Women randomized to elective cesarean delivery had higher postpartum morbidity rates (49.3% vs 6.7%).

Gimovsky et al randomized 105 laboring women with term nonfrank breech presentations to a trial of labor versus elective cesarean delivery. In this group of women, 47 had complete presentations, 16 had incomplete presentations (hips flexed, 1 knee extended/1 knee flexed), 32 had double-footling presentations, and 10 had single-footling presentations. Oxytocin was allowed for dysfunctional labor. Of the trial labor group, 44% had successful vaginal delivery. Most cesarean deliveries in the trial labor group were performed for inadequate x-ray pelvimetry. No difference in neonatal morbidity existed between infants delivered vaginally versus infants delivered by cesarean delivery, although a higher maternal morbidity rate occurred in the cesarean delivery group.

In 1993, Cheng and Hannah reviewed 24 studies comparing vaginal versus cesarean delivery for the term breech fetus.

Table 2. Vaginal Versus Cesarean Delivery for the Term Breech Fetus

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In 2000, Hannah and colleagues completed a multicenter randomized clinical trial involving 2088 term fetuses in frank or complete breech presentations at 121 institutions in 26 countries. The individuals were randomized into a planned cesarean delivery group or a planned vaginal birth group. Exclusion criteria were estimated fetal weight heavier than 4000 g, hyperextension of the fetal head, lethal fetal anomaly or anomaly that may result in difficulty with delivery, or contraindication to labor or vaginal delivery (eg, placenta previa).

Women randomized to a cesarean delivery were scheduled to be delivered after 38 weeks?gestation, unless the fetus had converted to cephalic presentation. Women randomized to a vaginal delivery were treated expectantly until labor ensued. Electronic fetal monitoring was either continuous or intermittent. Inductions allowed for standard obstetrical indications, such as postterm gestations. Augmentation with oxytocin was allowed in the absence of apparent fetopelvic disproportion. Epidural analgesia was permitted.

Adequate labor was defined as a cervical dilatation rate of 0.5 cm/h in the active phase of labor and descent of breech to the pelvic floor within 2 hours of achieving full dilatation. Vaginal delivery was spontaneous or assisted and was attended by an experienced obstetrician as determined by the department head. Cesarean deliveries were performed for inadequate progress of labor, nonreassuring fetal heart rate, or conversion to footling breech. Results were analyzed by intent-to-treat (ie, subjects were analyzed by randomization group, not by ultimate mode of delivery).

Of 1041 women in the cesarean delivery group, 941 (90.4%) underwent cesarean delivery. Vaginal delivery occurred for those with immanent vaginal birth (59), for those with a patient request (29), and for those with cephalic presentation (12). No reason was given for 5 of the vaginal deliveries who were first intended to be cesarean deliveries. Of 1042 women in the planned vaginal group, 591 had vaginal deliveries. Cesarean delivery was performed for those with fetopelvic disproportion or failure to progress in labor (226), nonreassuring fetal heart rate tracing (129), a footling breech (69), a patient request (61), obstetrical or medical indications (45), or cord prolapse (12). No reason was given for 8 of the cesarean deliveries who were first intended to be vaginal deliveries.

Combined measurement of perinatal mortality, neonatal mortality, or serious neonatal morbidity was significantly lower in the planned cesarean group versus the planned vaginal group (5% vs 1.6%, P <0.0001). Six of 16 neonatal deaths were associated with difficult vaginal deliveries, and 4 deaths were associated with fetal heart rate abnormalities. The reduction in risk in the cesarean group was even greater in those participating countries with overall low perinatal mortality rates as reported by the World Health Organization. The difference in perinatal outcome held after controlling for the experience level of the obstetrician. No significant difference was present between the 2 groups in maternal mortality or serious maternal morbidity within the first 6 weeks of delivery (3.9% vs 3.2%, P = 0.35).

Only one prospective randomized study has been performed on the preterm breech, a randomized clinical trial of 38 women with preterm labor (28-36 wk) with breech presentations. Of these women, 20 were randomized to attempted vaginal delivery and 18 were randomized to immediate cesarean delivery. Of the vaginal group, 25% of patients underwent cesarean delivery for nonreassuring fetal heart rate tracing. Five neonatal deaths occurred in the vaginal group, and 1 neonatal death occurred in the cesarean delivery group. Two infants died from fetal anomalies, 3 infants died from respiratory distress, and 1 infant died from sepsis.

No nonanomalous infants who died were acidotic at delivery or had birth trauma. No significant differences in Apgar scores existed, although a trend toward lower Apgar scores existed in the vaginal group. The small number of enrolled subjects made reaching any definitive conclusions regarding the safety of vaginal breech delivery for the preterm breech difficult.

Retrospective analyses showed higher mortality in vaginal breech infants weighing 750-1500 g (26-32 wk), but less certain benefit was shown with cesarean delivery if the fetal weight was heavier than 1500 g (approximately 32 wk). This small subgroup (26-32 wk) may benefit from cesarean delivery, although this recommendation is based on retrospective data that is likely flawed by selection bias.

External cephalic version (ECV) is the transabdominal manual manipulation of the fetus into a cephalic presentation.

Historical considerations

Initially popular in the 1960s and 1970s, ECV virtually disappeared after reports of fetal deaths following the procedure. Reintroduced to the United States in the 1980s, it became increasingly popular in the 1990s.

Improved outcome may be related to the use of nonstress tests both before and after ECV, improved selection of low-risk fetuses, and Rh-immune globulin to prevent isoimmunization.

Procedure

Prepare for the possibility of cesarean delivery. Type and screen the blood of the patient, and obtain a consultation with an anesthesiologist. The night before the procedure, the patient should have nothing by mouth after midnight. Perform an ultrasound to confirm breech, to check growth and amniotic fluid volume, and to rule out anomalies associated with breech.

Perform a nonstress test (biophysical profile as back-up) prior to ECV to confirm fetal well-being.

Perform ECV in or near a delivery suite in the unlikely event of fetal compromise during or following the procedure.

ECV can be performed with 1 or 2 operators. An assistant may help turn the fetus or elevate the breech out of the pelvis or monitor the ultrasound position of the baby.

ECV is accomplished by judicious manipulation of the fetal head toward the pelvis while the breech is brought up toward the fundus. Attempt a forward roll first and a backward roll if the initial attempt is unsuccessful. No consensus exists on how many ECV attempts are appropriate at one time.

Following an ECV attempt, whether successful or not, repeat the nonstress test (biophysical profile if needed) prior to discharge. Also, administer Rh-immune globulin to women who are Rh negative. Be prepared for an unsuccessful ECV. Do not be ashamed if the ECV is unsuccessful. Some physicians induce labors following successful ECV, while others discharge and await spontaneous labor.

Success rate

Success rates vary widely but range from 35-86% (average 58%). Improved success rates occur with multiparity, earlier gestational age, frank breech, transverse lie, and in African American patients. Disagreement over influence of maternal weight, placental position, and amniotic fluid volume exist with regards to success rates.

Newman developed a Bishop-like score to predict ECV success.

Table 3. Scores to Predict External Cephalic Version Success

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The success rate was 0% with a score of less than 2 and 100% with a score of greater than 9. Significant overlap in scores between the successful and unsuccessful ECVs render the scoring system clinically less useful.

Zhang reviewed 25 studies of ECV in the United States, Europe, Africa, and Israel. The average success rate in the United States was 65%. Of ECVs, 2.5% reverted to breech (other estimates range from 3-5%) and 2% spontaneously verted to cephalic prior to labor (other estimates range from 12-26%). Spontaneous version rates depend on the gestational age when the breech is discovered, with the earlier breeches more likely to vert spontaneously.

ECV attempts to decrease the cesarean delivery rate for breech by 50% (83.2% to 36.7%). Because breech presentations complicate only 3-5% of all deliveries, decreasing the cesarean delivery rate for breeches by 50% has minimal impact on the overall cesarean delivery rate.

Hofmeyr from the Cochrane Database reviewed 6 randomized clinical trials of ECV versus no ECV at term. ECV was associated with significant reduction in breech presentations (relative risk [RR] 0.42, 95% CI 0.35-0.5) and reduction in cesarean delivery for breech (RR 0.52, 95% CI 0.39-0.71).

While most studies of ECV have taken place in university hospitals, ECV also has been shown to be effective in the private practice setting (Cook, 1993). Of 65 breeches at term, 60 were offered ECV. Successful ECV occurred in 32 of 60 (53%) patients, with vaginal delivery in 23 of 32 patients (72%) of successful ECVs. Of the 10 candidates for vaginal breech delivery, 8 (80%) had successful vaginal delivery. The overall vaginal delivery rate was 48% (31 of 65 patients), with no significant morbidity.

Cost analysis

In 1995, Gifford performed a cost analysis of 4 options for breech presentations at term: (1) ECV attempt on all breeches with attempted vaginal breech delivery for selected persistent breeches, (2) ECV on all breeches with cesarean delivery for persistent breech, (3) trial of labor for selected breeches with scheduled cesarean delivery for all others, and (4) scheduled cesarean delivery for all breeches prior to labor.

ECV attempt on all breeches with attempted vaginal breech on selected persistent breeches was associated with the lowest cesarean delivery rate and was the least costly approach. The second most cost-effective approach was ECV attempt on all breeches with cesarean delivery for persistent breeches.

Risks of external cephalic version

Uncommon risks of ECV include fractured bones, ruptured viscera, labor or premature rupture of membranes, abruptio placentae, fetomaternal hemorrhage (0-5%), and cord entanglement (<1.5%). A common risk of ECV is transient slowing of the fetal heart rate (as many as 40% of patients). This risk is believed to be a vagal response to head compression with ECV. It usually resolves once ECV is discontinued and has no adverse sequelae to the fetus.

Candidates

Women with breech presentation at term with reassuring fetal heart rate tracing and no contraindications to vaginal delivery are candidates. ECV usually is not performed on preterm breeches because they are more likely to spontaneously vert to cephalic presentation and are more likely to revert to breech after successful ECV (approximately 50%).

No difference exists in rates of breech presentations at term or in overall cesarean delivery rates after preterm ECV.

If complications arise with ECV, a term infant can be delivered with a presumably better outcome than a preterm infant.

Contraindications

Absolute contraindications include multiple gestations with breech presenting, existence of contraindications to vaginal delivery (herpes simplex virus, previa), and those with nonreassuring fetal heart rate tracing.

Relative contraindications include polyhydramnios or oligohydramnios, fetal growth restriction, uterine malformation, and fetal anomaly.

Controversial candidates

Prior uterine incision: Scant data are available. In 1991, Flamm attempted ECV on 56 women with 1 or more prior low-transverse cesarean deliveries. The success rate of ECV was 82%, with successful vaginal births after cesarean in 65% of the successful ECVs. No uterine ruptures occurred during attempted ECV or subsequent labor, and no significant fetal complications occurred.

Labor: In 1985, Ferguson reported on 15 laboring women with term breeches and intact membranes. Four patients were dilated greater than 5 cm (2 women were 8 cm dilated). Ritodrine was used for acute tocolysis, and intrapartum ECV was attempted. ECV was successful in 11 of 15 cases, with 10 of 11 subsequent vaginal deliveries. No adverse effects were noted. Further studies are needed to evaluate the safety and efficacy of intrapartum ECV.

Tocolytics

Conflicting data exist regarding the benefit of intravenous or subcutaneous beta-mimetics in improving ECV rates.

In 1996, Marquette performed a prospective randomized double-blind study on 283 women with breech presentations between 36 and 41 weeks?gestation. Subjects received either intravenous ritodrine or placebo. The success rate of ECV was 52% in the ritodrine group versus 42% in the placebo group (P = 0.35). When only nulliparous women were analyzed, significant differences were observed in the success of ECV (43% vs 25%, P <0.03). Success rates were significantly higher in parous versus nulliparous women (61% vs 34%, P <0.0001), with no additional improvement with ritodrine.

In 1999, Hofmeyr, from the Cochrane Database, reviewed 6 trials of tocolysis prior to ECV and concluded that routine tocolysis resulted in fewer failures of ECV (RR 0.77, 95% CI 0.64-0.92).

Whether tocolysis should be used routinely or selectively is still unclear.

Regional anesthesia

Epidural or spinal analgesia requires analgesic levels comparable to those for cesarean delivery.

Advantages of epidural or spinal analgesia are that it allows relaxation of the anterior abdominal wall, making palpation and manipulation of the fetal head easier. Epidural or spinal analgesia eliminates pain that may cause bearing down and tensing of rectus muscles. If ECV is successful, patients can be induced with epidural in place or the epidural can be removed and the patient is sent home to await spontaneous labor. If ECV is unsuccessful, one can proceed to cesarean delivery under epidural anesthesia.

Disadvantages are the risks of regional anesthesia. Lack of maternal pain potentially results in excessive force being applied to the fetus without the knowledge of the operator. Induction after successful ECV might increase cesarean delivery risk for failed induction. Cesarean delivery following unsuccessful ECV might result in iatrogenic respiratory distress syndrome or deprive the fetus the opportunity to spontaneously vert to cephalic presentation.

In 1994, Carlan retrospectively analyzed 61 women who were at more than 36 weeks?gestation having ECV with or without epidural. The success rate of ECV was 59% in the epidural group and 24% in the no epidural group (P <0.05). In 7 of 8 women with unsuccessful ECV without epidural, repeat ECV attempt with epidural was successful. Of the epidural group, 86% had obstetrical intervention (induction or cesarean delivery) immediately after the ECV. No adverse effects on maternal or perinatal morbidity/mortality occurred.

In 1997, Schorr randomized 69 women who were at more than 37 weeks?gestation to either epidural or control prior to attempted ECV. Those in whom ECV failed underwent cesarean delivery. The success rate of ECV was 69% in the epidural group and 32% in the control group (RR 2.12, 95% CI 1.24-3.62). The cesarean delivery rate was 79% in the control group and 34% in the epidural group (P = 0.001). No complications of epidural anesthesia and no adverse fetal effects occurred.

In 1999, Dugoff randomized 102 women who were more than at 36 weeks?gestation with breech presentations to either spinal or no spinal anesthesia. All women received 0.25 mg SQ terbutaline. The success rate of ECV was 44% in the spinal group and 42% in the nonspinal group, which is not statistically significant.

Acoustic stimulation

Johnson and Elliott performed a randomized blinded crossover trial on 23 women comparing acoustic stimulation prior to ECV to a control group when the fetal spine was in the midline (directly back up or back down). Twelve of 12 fetuses shifted to a spine-lateral position after acoustic stimulation, and 11 (91%) underwent successful ECV, compared to 0 of 11 shifts and 1 (9%) successful ECV (P <0.0001) in the placebo group. After crossover to the alternate modality, of the 10 fetuses in whom ECV initially failed after no acoustic stimulation, all 10 shifted to spine-lateral following acoustic stimulation and 80% of these had successful ECV, compared to 0 of 1 ECV successes in the acoustic stimulation to placebo crossover.

Vaginal delivery rates after successful version

The rate of cesarean delivery ranges from 0-31% after successful ECV.

In 1994, a retrospective study by Egge of 76 successful ECVs matched with cephalic controls by delivery date, parity, and gestational age failed to note any significant difference in the cesarean delivery rate (8% in ECV group, 6% in control group).

Vaginal breech delivery can be performed for select cases of breech presentation after 32 weeks?gestation, although a recent randomized clinical trial suggests an increased rate of perinatal mortality and serious perinatal morbidity.

Patients must be informed of potential risks and benefits to the mother and baby of both vaginal breech delivery and cesarean delivery. The likelihood is high that the trend will continue toward 100% cesarean delivery for breeches and that vaginal breech deliveries will become a lost art.

ECV is a safe alternative to vaginal breech delivery or cesarean delivery, reducing the cesarean delivery rate for breech by 50%.

Consider adjuncts such as tocolysis, regional anesthesia, and acoustic stimulation to improve ECV success rates.