Persistent OP position can be considered to be a high-risk labor in that the likelihood of cesarean delivery or instrumental delivery is greater than the normal OA position. In fact, while they make up 5.5% of all laboring women, they account for 12% of all cesarean deliveries undertaken for dystocia (6). Persistent posterior positions are also associated with an increased incidence of premature rupture of the membranes, augmentation, episiotomies, vaginal lacerations, hemorrhage, and third or fourth degree tears (2,6). Traditionally, obstetricians attempted to rotate the fetus to an OA position prior to delivery, either manually or using forceps. This technique has become increasingly unpopular as it has been associated with increased maternal and fetal trauma, and more junior obstetricians have less experience and confidence in the use of high rotational forceps (e.g., Kielland’s). Instead, the obstetrician now is more likely to allow the labor to progress and deliver the baby in the OP position if rotation to OA does not occur naturally. Spontaneous vaginal delivery in this manner has been shown to be successful in up to a third of nulliparous women and 55% of multiparas (6).

Owing to the often prolonged and exaggerated pain that women undergo and despite the debate noted above, the OP position remains a common indication for regional analgesia in labor. As has previously been noted, low back pain is a particular problem and care should be taken that the block covers the sacral roots. This requires a careful assessment of the dermatomal spread although it should be noted that it may take several top-ups if using an intermittent maintenance technique or several hours if using a continuous infusion. It is generally accepted that the use of a CSE technique results in a faster onset of analgesia than the normal extradural approach and may also give an earlier sacral block. Despite a recent Cochrane review concluding that there was no overall benefit to offering CSE over normal low dose epidurals in labor (8), it might be suggested that its use would be suitable for labor analgesia in OP pregnancies. However, as yet there is no randomized controlled trial to support this view. Some women never gain full relief from the sacral ache and low back pain of the OP position with the usual low dose epidural mixtures of local anesthetic and opioid despite an apparently good sensory block, and these women may need stronger concentrations of local anesthetic agents.

The widespread use of low dose local anesthetic solutions has reduced the amount of motor block seen with modern labor epidurals (9). If the position of the vertex is initially OP, profound relaxation of the pelvic floor muscles and perineum may prevent spontaneous rotation to a normal OA position or allow malrotation of an initially OA fetus to the OP position. However, during an instrumental delivery it may be necessary to assist the obstetrician by intentionally relaxing the pelvic floor to allow for easier placement of forceps or ventouse cup, reducing the risk of vaginal injury (and trauma to the fetal head). This can be achieved by increasing the density of the block with a strong solution of local anesthetic such as 2% or 3% 2-chloroprocaine, 2% lidocaine (with or without adjuvants), 0.5% bupivacaine or levobupivacaine, or 0.75% ropivacaine depending on the urgency and individual preference.

ECV involves the manipulation of the fetus through the maternal abdominal wall in order to rotate it from a breech to a vertex presentation. The success rate of ECV is between 30% and 85% (25,26,27,28) but there are many factors that influence the outcome. These include race, parity, uterine tone, amniotic fluid volume, engagement of the breech and whether
the head is palpable, and the use of tocolysis (27,28,29,30). Tocolytics used include terbutaline, ritodrine, and salbutamol.

The aim of ECV is to reduce the adverse outcomes associated with breech delivery. A Cochrane review on ECV at term showed that there was a statistically significant reduction in non-cephalic birth (five trials, 433 women; relative risk (RR) 0.38, 95% confidence interval (CI): 0.18–0.80) and cesarean delivery (five trials, 433 women; RR 0.55, 95% CI: 0.33–0.91) when ECV was attempted (31). The timing of ECV is also a potential factor in outcome. It has been suggested that ECV before term (34 to 35 weeks’ gestation) may be associated with a greater reduction in non-cephalic births when compared to ECV at term (32). This was investigated in the Early ECV 2 Trial (33) which determined that while there was an increased reduction in non-cephalic presentation at birth when compared to ECV at term, there was no reduction in the rate of cesarean delivery and that there may be an increase in preterm births (this association did not reach statistical significance).

ECV is a safe procedure with a very low complication rate (34,35). However, there are case reports of placental abruption, uterine rupture and feto-maternal hemorrhage. The incidence of immediate emergency cesarean delivery is estimated at around 0.5% (34,35).

Pain and discomfort can be considerable during ECV and is associated with a lower chance of success (36). However, it has also been considered a marker for potential complications and thus there has been reluctance amongst obstetricians for regional anesthesia to be undertaken for fear of masking warning signs that a complication has occurred. More recently though, there has been increased interest in the use of regional analgesia or anesthesia in order to facilitate ECV. Schorr et al. assigned 35 women to receive an epidural (2% lidocaine with epinephrine) and 34 to no epidural prior to ECV (37). They demonstrated a better success rate in the epidural group (67% vs. 32%, RR 2.1, CI: 1.2–3.6). Mancuso et al. also assigned 108 women equally between epidural (2% lidocaine with fentanyl) and control groups (38). They reported a higher success rate in the epidural group (59% vs. 33%, RR 1.8, CI: 1.2–2.8). In 2010, Weiniger et al. (39) replicated the findings of their own previous study. They demonstrated a higher success rate for regional anesthesia when they assigned 64 women equally between spinal anesthesia (7.5 mg bupivacaine) and control groups (87% vs. 57.5%, P = 0.009; 95% CI: 0.075–0.48). It is interesting to note the relatively high success rate in the control group as this had been a criticism of previous studies, i.e., that a success rate in the control group of 30% to 35% did not adequately reflect normal practice. A number of other studies have also demonstrated that in those women who have previously undergone unsuccessful ECV, the subsequent use of neuraxial anesthesia can result in a successful outcome with success rates ranging from 39.7% to 89% (40,41,42).

As the published evidence is conflicted with respect to benefit from using neuraxial block for ECV (43,44,45), a meta-analysis was published in 2010 to review the evidence to date (46). The authors demonstrated that the main difference between the studies was in dose and not technique. They found that if an anesthetic dose was used in the study group the outcome was a statistically significant endorsement of neuraxial block but if an analgesic dose was used then no benefit was found. They also found that apart from maternal hypotension, the incidence of serious adverse events during ECV was unaffected by neuraxial block. It should be noted, however, that given the relatively low incidence of serious adverse events, none of the studies individually were adequately powered to detect statistically significant differences in complication rates.

Currently, there is something of a transatlantic divide in opinion about the use of regional techniques for ECV, being much more common in North America than in the United Kingdom, where neuraxial block is not routinely offered for ECV. However, the increasing body of evidence to support its use suggests another area in which the anesthesiologist may have a role in improving the experience and outcome for women with breech presentations.

Probably one of the most contentious areas in the obstetric management of breech presentation is the mode of delivery. In 2000, the TERM breech trial was published in the Lancet (47). A large, multicentre, randomized controlled trial, it compared maternal and fetal outcomes of vaginal breech delivery versus planned cesarean delivery and included data from 2,083 women in 26 countries. The most significant finding was an incidence of neonatal mortality or serious morbidity of 1.6% in the planned cesarean group compared to 5% in the planned vaginal delivery group. This difference was even more marked among countries with a low perinatal mortality rate (UK, USA, Canada). There was no difference in maternal outcomes between the two groups. Following the publication of this study, the rate of cesarean delivery for breech presentation, which had already been rising, increased dramatically. In the United States, the cesarean delivery rate for breech was 11.6% (24) in 1970; by 2001 this had risen to 86.2% (48). A study from the Netherlands directly examined the impact that the TERM breech trial had on the national cesarean delivery rate for breech presentation and found an increase from 50% to 80% in just 2 months following the publication date (49). The American College of Obstetricians and Gynecologists (ACOG) were so moved by the data that in 2001 they amended their recommendation on mode of delivery saying “Patients with a persistent breech presentation at term in a singleton gestation should undergo a planned cesarean delivery” (50).

However, as is common for headline studies, the acclaim was not universal. Many observers felt that flaws in the study, particularly with regard to selection criteria and the conduct of labor, led to a misleading result and that vaginal delivery for breech presentation was still a valid option for a defined group of women (19,51,52). Risk factors for adverse outcomes in vaginal breech delivery include hyperextension of the fetal neck, prolonged labor, the lack of an experienced clinician at delivery and extremes of fetal weight at term (<2,500 g and >4,000 g) (19). Those who favor vaginal delivery believe that by excluding the women who fall into these categories, it is possible to identify patients who are more likely to have a successful outcome and avoid the potential complications of cesarean delivery. It should be noted, however, that clinicians who are experienced in vaginal breech delivery are becoming increasingly rare as training opportunities become more limited in an obstetric climate that favors planned cesarean delivery for these women. Further support for the role of vaginal delivery comes from a 2-year follow-up study of the TERM breech trial. The investigators found that there was no difference in risk of death or neurodevelopmental abnormality at 2 years of age regardless of mode of delivery (53). Potentially this demonstrates that the increased risk of serious morbidity found in the vaginal delivery group in the original study does not lead to any long-term complications.