‘If the feet of the child come foremost, you must take care to baptize them immediately …’
Paul Portal
The Compleat Practice of Men and Women Midwives. London: J. Johnson, 1763, p23
Over the past 30 years there has been a worldwide trend to deliver a greater proportion of breech presentations by caesarean section. In 2000 an international multicentre randomized-controlled trial of planned vaginal delivery versus planned elective caesarean section for uncomplicated term breech presentation confirmed that perinatal mortality and serious neonatal morbidity were significantly lower in the planned caesarean group. Further analysis of the Term Breech Trial showed that prelabour caesarean and caesarean during early labour were associated with the lowest adverse perinatal outcome due to labour or delivery and that vaginal delivery had the highest risk of adverse outcome. Furthermore, the widespread adoption of elective caesarean for breech delivery in the Netherlands was associated with an improvement in neonatal outcome. As a result, although the conclusions of this trial were disputed, where appropriate facilities existed caesarean section for the term breech become the standard of care in many hospitals and was supported by national guidelines.
Subsequently, secondary analysis by the Term Breech Trial group showed that the mortality and morbidity outcomes of the children at 2 years of age were similar. In addition, compared to vaginal delivery, maternal morbidity was increased in those women delivered by caesarean section in labour, but not higher in those delivered by elective caesarean without labour. With the availability of the secondary analysis, a number of publications appeared advocating selective vaginal breech delivery, supported by some institutional data. . As a result many national guidelines were modified to support those willing to provide selective vaginal breech delivery under strict selection and management criteria.
However, even before the Term Breech Trial results were published, most obstetricians had ‘voted with their scalpels’. The trial results and an increasingly critical medico-legal climate only served to consolidate this approach. Furthermore, the discussion involved in fully informed consent often hardens the resolve of the woman to choose elective caesarean delivery. Even in the large multi-institutional study from France and Belgium, which promoted breech vaginal delivery with strict selection and intrapartum management criteria, only 22% of all term breech presentations were delivered vaginally. In Dublin, where obstetric leaders wrote in favour of selective vaginal delivery of the term breech, the caesarean breech delivery rate rose from 77% to 90% respectively in the 8-year epochs before and after the Term Breech Trial.
For the preterm breech (24−32 weeks’ gestation) recent evidence suggests that caesarean delivery reduces perinatal death and morbidity compared to attempted vaginal delivery. Thus, the majority of obstetricians choose caesarean section for the viable preterm breech.
The above notwithstanding, there are still occasions when vaginal breech delivery will have to be undertaken, for the following reasons:
- 1.
Labour may proceed so rapidly that there is inadequate time to perform caesarean section. Even in the Term Breech Trial almost one in 10 of those assigned to delivery by caesarean section were delivered vaginally.
- 2.
Labour and delivery may occur in a setting where caesarean section is unavailable or carries greater risks than are justified by the perceived perinatal benefit.
- 3.
From erroneous observation or lack of opportunity the diagnosis of breech presentation may not be made until late in the second stage of labour, when it is too late to perform caesarean section.
- 4.
The woman, although informed of the increased perinatal risks, may still choose to proceed with labour and vaginal delivery.
In addition, while caesarean section may reduce the risks of fetal trauma, it is still necessary to know and perform the appropriate manoeuvres required to safely deliver the fetus through the uterine incision. This applies particularly to the after-coming head of the fetus, and these manoeuvres are similar to those required for atraumatic vaginal breech delivery. Thus, it remains essential for the accoucheur to acquire and retain the skills necessary to protect the fetus during vaginal delivery. Unfortunately, one of the side effects of an almost universal policy of caesarean section for breech delivery is that it becomes a self-fulfilling prophecy that obstetric trainees will have limited opportunities to acquire the skills necessary for safe vaginal breech delivery. As in other areas of our specialty, simulation and manikin training have to supplement on-the-job acquisition of experience. These skills may also be augmented by the routine and systematic rehearsal of all the manoeuvres during delivery of the breech through the uterine incision at every caesarean section for breech presentation.
Intrapartum Fetal Risks
The main reasons for the poor outcome of the breech presentation, compared with the fetus in cephalic presentation, are prematurity and congenital anomalies. It is also possible that there are subtle neurological abnormalities that cause the fetus to lie in breech presentation and which may contribute to a poorer outcome irrespective of the method of delivery. During labour and delivery the fetus in breech presentation is subjected to the following risks:
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A higher incidence of cord entanglement or cord prolapse, especially in the footling breech, may lead to asphyxia. In addition, when the after-coming head of the breech enters the pelvic brim the associated cord compression can cause asphyxia if there is undue delay in descent and delivery of the head.
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The fetal buttocks and trunk have a smaller diameter than the head. This is particularly exaggerated in the preterm fetus. Thus, there is a danger that the buttocks and trunk will slip through an incompletely dilated cervix causing entrapment of the arms and/or the head, leading to trauma and asphyxia.
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Fracture or dislocation of limbs may occur and this is most likely with extended or nuchal displacement of the arms.
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Damage to intra-abdominal organs may be sustained, especially the liver and spleen, if the hands of the accoucheur are placed above the pelvis and encircle the abdomen during manipulations.
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Cervical spine dislocation or fracture due to excessive traction during delivery of the head, particularly if there is hyperextension of the neck because of undue elevation of the body of the fetus while the head is still in the pelvis.
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Brachial plexus injury due to inappropriate and excessive traction on the shoulders in an attempt to deliver the head.
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Traction on the fetal trunk while the head remains in the pelvis may tend to pull the base of the fetal skull away from the vault.
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As the fetal head descends across the pelvic floor and perineum there is compression and, if delivery of the fetal head is not carefully controlled, sudden decompression as the head delivers. This may cause a tentorial tear and intracranial haemorrhage, risks which are increased when there is concomitant hypoxia.
In essence, the job of the obstetrician is to protect the fetal brain during labour and delivery, and nowhere is this duty more critical than in breech delivery. The key is to apply a well-rehearsed sequence of manoeuvres and achieve the balance between excessive haste leading to traumatic delivery and undue delay with its risk of asphyxia. In most cases a minimal amount of interference is required but there should always be active control and protection of the fetal head at delivery.
Anaesthesia
For some women a combination of narcotic, inhalation and pudendal block will provide adequate analgesia and allow the most natural progression of the first and second stages of labour. Epidural block provides the best pain relief and also has the advantage of blunting the maternal bearing-down effort in the late first stage of labour. In the nulliparous woman epidural block may be required for adequate pain relief, but can prevent the desired maternal bearing-down effort in the second stage of labour. This may lead to uncertainty as to whether such failure of descent is due to impaired maternal propulsive effort or due to feto-pelvic disproportion. In carefully selected cases oxytocin augmentation may be used, but with extreme caution. On the other hand, the multiparous woman often receives adequate pain relief with narcotic, inhalation and pudendal block, but epidural analgesia has the benefit of blunting her bearing-down reflex, which may occur prematurely in the late first stage of labour. The ideal, therefore, is a selective epidural block that allows retention of motor activity, while providing a humane degree of sensory block. Ideally, an anaesthetist should be present at all breech deliveries, either to supervise the regional block or to provide rapid general anaesthesia and/or uterine relaxation if necessary.
First stage of Labour
In general, the frank and complete types of breech presentation fill the lower uterine segment and are well applied to the cervix. In contrast, the footling breech ( Fig 16-1 ) may not and there is a much higher incidence of cord prolapse. For this reason, and the propensity of the footling breech to slip through the incompletely dilated cervix, labour is best avoided with a footling breech presentation unless there is no alternative. The frank or complete breech at term, of reasonable size (2000–3800 g), is most likely to result in a safe vaginal delivery if the first stage of labour is smooth and progressive.
Oxytocin augmentation is permissible, particularly in the nulliparous breech, for similar indications to cephalic presentation. However, this would only be undertaken in cases where caesarean delivery is not a realistic alternative. In the Term Breech Trial the perinatal outcome was significantly worse in cases in which oxytocin augmentation was used. Amniotomy in labour is acceptable if the breech is well applied to the cervix. In general, however, one tries to leave the membranes intact as long as possible. X-ray pelvimetry is of no proven value for management of the breech in labour.
When the membranes rupture spontaneously during labour an immediate pelvic examination should be done to exclude cord prolapse.
It is essential to be sure that the cervix is fully dilated and not palpable before encouraging maternal bearing-down effort. Because the breech is usually smaller than the after-coming head it is possible, even at term, for the breech to appear at the introitus before the cervix is fully dilated. The early appearance of male external genitalia can also be misleading. It is therefore a cardinal rule that one must check for full cervical dilatation before proceeding with delivery.
Conduct of Breech Delivery
Delivery of the Breech and Legs
With uterine contractions and maternal effort the breech should be allowed to descend to the perineum. The woman can then be placed in the lithotomy position and, if epidural analgesia has not already been established, a pudendal block is performed along with local anaesthetic infiltration of the perineum. The guiding principle at this time is ‘keep your hands off the breech’, be patient, and await the appearance of critical anatomical landmarks ( Fig 16-2 ). The most helpful manoeuvres involve flexion and rotation but not traction. The following sequence should be observed:
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As the breech descends it meets the obstruction of the perineum. With further maternal effort the anterior buttock of the fetus ‘climbs up’ the perineum until the fetal anus is visible over the fourchette – usually manifest by a bead of meconium. The breech does not recede in between contractions. At this point the combination of descent and lateral flexion of the fetus has reached its maximum and further progress will only occur when the obstruction of the perineum is removed. This, therefore, is the point at which episiotomy is performed, with special care to avoid injury to the fetal genitalia. The comparable timing for a footling breech presentation is when the fetal buttocks reach the perineum.
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A combination of the above observations and testing the distension of the perineum with a finger will guide the precise timing of episiotomy, with particular care taken to avoid cutting fetal soft tissues. Wait until the beginning of a contraction and then perform the episiotomy, which ensures maternal effort throughout the entire uterine contraction to help deliver the buttocks and legs. With a complete breech, maternal effort alone will usually deliver the legs and lower trunk.
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With a frank breech presentation the extended legs often require assistance in the form of slight abduction at the hip and flexion of the knee for delivery. One hip is usually anterolateral and two or three fingers should be placed along the fetal thigh above the knee to slightly abduct and flex the hip, followed by flexion of the knee on the fetal body. The more ‘splinting’ fingers that can be placed along the thigh to conduct this manoeuvre the greater the distribution of force, which lessens the chance of fracture of the femur. This principle applies to all manoeuvres involving the limbs. Once the anterior leg has been flexed and delivered the breech should be gently rotated so that the other hip is anterolateral and the same procedure repeated on the other side ( Fig 16-3 ).
FIGURE 16-3
Assisted delivery of extended legs. The fingers splint the femur, slightly abduct the thigh and then flex the hip and knee.
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The remainder of the abdomen and lower thorax will usually deliver with maternal effort alone. At this point gently bring down a loop of umbilical cord so it is not under tension for the remainder of the delivery.
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Throughout delivery of the legs, abdomen and lower thorax there should be minimal or no traction, which is likely to cause extension of the arms and fetal head – both undesirable. Other than assisting the delivery of extended legs with flexion and ensuring that the fetal back remains anterior, one should rely on maternal effort alone.
Delivery of the Shoulders and Arms
A critical stage of the delivery has now been reached. As the fetal trunk delivers and descends the fetal head will enter the pelvic brim, causing compression of the umbilical cord. Ideally, the rest of the delivery should be accomplished within 2–3 minutes, to avoid asphyxia. On the other hand, one must not panic and employ undue haste, potentially leading to trauma of the arms, brachial plexus, cervical spine and brain. Although it may not seem so, 2–3 minutes is ample time to systematically and carefully go through the manoeuvres to effect safe delivery:
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With maternal effort alone the lower border of the more anterior scapula will become visible under the pubic arch. Provided no undue traction has been applied the arms are usually flexed across the fetal chest. Using two fingers pass them over the fetal shoulder and down along the humerus, splinting and sweeping it across the chest to deliver the elbow and forearm. The fetus is then rotated 90° to bring the other scapula into view and the same procedure is repeated.
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When rotating the fetus for this and other purposes it is important to avoid gripping the fetal abdomen. The obstetrician’s hands should grasp the thighs with the thumbs over the sacrum and the index fingers around the iliac crest. In this way the intra-abdominal contents will not be traumatized. The use of a small sterilized towel will assist the correct placement and help maintain the grip ( Fig 16-4 ).
