Chapter 9 – Breech Delivery




Abstract




Predisposing Factors





Chapter 9 Breech Delivery


Enaya Mirza and Edwin Chandraharan




Key Facts


Definition




  • Breech presentation refers to a situation in which the buttocks, feet or knee of the fetus are positioned in the pelvis to be delivered first.



  • The torso and head of the fetus in relation to the breech are in a longitudinal lie.


Incidence




  • At term the incidence of breech presentation is 3%–4% [1].



  • The incidence is higher in preterm gestations and can be up to 20% in extreme prematurity at 28 weeks’ gestation [2].



  • The incidence is higher in primiparous women, and recurrence rates in subsequent pregnancies are significant.


Types of Breech Presentation




  • Breech presentations can be classified as extended, flexed (both terms referring to the orientation of the knee) or footling (Figure 9.1).



  • Extended breech: The knees are both extended with the hips flexed and feet above the buttocks. This is the most common breech presentation, with an incidence of 65% [2].



  • Flexed breech: The knees are both flexed and above the buttocks.



  • Footling breech: One or both feet or knee is below the buttocks and presenting.





Figure 9.1 Types of breech. (a) Complete breech – flexion at hip and knee joints (elbows flexed too). (b) Extended breech – flexion at the hip but extension at the knee joint. (c) Footling breech – extension at both hip and knee joints. (d) Knee presentation.



Predisposing Factors




  • Factors that make a diagnosis of breech presentation more likely can be maternal or fetal (Table 9.1).




Table 9.1 Predisposing factors for breech presentation













Power




  • Uterine malformation (e.g. bicornuate or septate uterus)



  • Uterine fibroids



  • Lax uterus (grand multiparty)



  • Polyhydramnios (alters the pyriform shape of the uterus)


Passenger




  • Prematurity



  • Multiple pregnancy



  • Previous breech presentation



  • Fetal malformation (e.g. hydrocephalus, anencephaly)


Passage




  • Placenta previa or cornual placental position



  • Fibroids in the lower uterine segment



  • Pelvic masses (e.g. ovarian cysts, pelvic kidney)



  • Abnormalities in the bony pelvis (congenital and acquired)



Key Implications




  • Breech presentation at term is associated with worse neonatal outcomes when compared to cephalic presentation irrespective of the mode of delivery. This may reflect the fact that breech presentation is more likely in extreme prematurity and congenital malformation, both independently linked with worse neonatal outcomes.



  • Meta-analysis of retrospective observational studies suggests that elective caesarean section for breech reduced the perinatal morbidity and mortality two- to four-fold when compared with vaginal birth. This could reflect that caesarean section avoids labour and shortens the pregnancy, which otherwise may progress past term. Both labour and prolonged pregnancy are independent risks to perinatal mortality and morbidity. The excess risk of a breech presentation alone may be as small as 1 per 1000 [1].



  • The term breech trial published in 2000 led to a widespread reduction in attempted vaginal breech birth and an increase in the use of elective caesarean for breech delivery. This has over the years led to a reduction in operator experience in vaginal breech birth and therefore a reduction in skilled operators confident in performing an assisted vaginal breech birth. The presence of a skilled operator is essential for a safe and successful vaginal breech delivery.



  • A recent retrospective study of more than 15 000 women found no difference in long-term childhood outcomes including cerebral palsy, infant mortality and developmental delay later in childhood when comparing planned vaginal and planned caesarean breech birth [3].



  • The primary concern during a breech vaginal delivery is possible trauma and difficulty in delivering the after coming head, which tends to be the largest circumferential part of a baby. This may translate to mortality or morbidity for the baby.



Key Pointers




  • A thorough antenatal assessment should be performed to identify factors that may decrease the chance of a successful breech vaginal delivery and increase the risk. Contraindications to an attempted vaginal breech delivery are detailed in Table 9.2.



  • Based on the antenatal assessment women may be offered external cephalic version (ECV), elective caesarean section or a planned assisted vaginal breech delivery. There should be a documented discussion with the mother on the benefits and risks to her and the baby for each appropriate option. A summary of these can be found in Table 9.3.



  • Appropriate case selection, operator skill and correct intrapartum management are determinants of a safe vaginal breech delivery.



  • Mode of delivery for an undiagnosed breech attending in labour should be individualised. Dilatation, contraindications to normal vaginal delivery, presence of an operator skilled in vaginal breech delivery, signs of fetal compromise and maternal choice should all be considered before making a decision.



  • Oxytocin may be used in the first stage if contractions are inadequate and there are no signs otherwise of a feto-pelvic disproportion. The decision to start Syntocinon should be made by a senior clinician. If progress is still slow despite a short trial of Syntocinon, then a caesarean section is recommended.



  • Oxytocin should be used with extreme caution in the second stage and only if contractions are genuinely suboptimal (fewer than 3–4 every 10 minutes, or short lasting) with no evidence of a mechanical cause. If the breech has not descended within 2 hours of a passive phase while the contractions have been adequate, then a caesarean section should be considered.




Table 9.2 Options for management of breech presentation











  • External cephalic version



  • Spontaneous breech delivery



  • Assisted vaginal breech delivery



  • Total breech extraction



  • Elective caesarean section




Table 9.3 Contraindications to assisted vaginal breech delivery











  • Any pre-existing contraindications to vaginal birth (e.g. placenta praevia, compromised fetal condition, uterine malformations)



  • Inadequate pelvis (on clinical examination or prior radiological evidence, e.g. road traffic accident with pelvic fractures)



  • Footling or kneeling breech presentation (Figure 9.1c, d)



  • Large baby (usually defined as larger than 3800 g)



  • Growth-restricted baby (usually defined as smaller than 2000 g)



  • ‘Star-gazing’ appearance – hyperextended fetal neck in labour (diagnosed with ultrasound or X-ray where ultrasound is not available)



  • Unavailability of a clinician trained in vaginal breech delivery, at the time of birth



  • Previous caesarean section (relative contraindication)



Key Actions



General Principles for an Assisted Breech Delivery




  • A skilled multidisciplinary team should be available. This includes a senior obstetrician, senior midwives who have the skill and expertise in assisted vaginal breech birth, as well as an anaesthetist and the neonatal team.



  • Confirm type and position of the breech, preferably using ultrasound. Identify the position of the descending sacrum as anterior or posterior and note the laterality. Although it may be possible to deliver the breech in a sacro-lateral position, assisted breech delivery should aim to keep the sacrum anterior to avoid the risks of deflexion and entrapment of the ‘after-coming’ fetal head.



  • The delivery itself should be in a centre with skilled and experienced staff. It is not essential to conduct the delivery in operating theatres, though some clinicians may prefer this in case an emergency caesarean is required.



  • Active pushing should not be commenced until the breech becomes visible at the perineum.



  • The use of episiotomy during the delivery should be selective and based on how distensible the perineum is for the delivery. Routine use of episiotomy may not be required, for example, in a multiparous woman or a preterm baby.



  • Continuous fetal monitoring should be employed throughout a breech labour as well as during delivery.



Conducting the Assisted Vaginal Breech Delivery


The technique for delivering in this circumstance can be considered in three stages:




  • Delivery of legs and buttocks



  • Delivery of the trunk, arms and shoulders



  • Delivery of the ‘after-coming’ head



Delivery of the Legs and Buttocks

Early, unnecessary intervention leads to poorer outcomes, and therefore lithotomy position should be avoided until the breech is clearly visible at the perineum without any retraction in between contractions [4]. The delivery of the buttocks and legs should occur as a result of good contractions and maternal effort with little or no hands on assistance required. The circumstance under which manual assistance will be needed is to keep the sacrum anterior, to help deliver the legs in the case of an extended breech or to perform an episiotomy if required. It is obvious that in cases of abnormalities noted on the fetal heart rate, an urgent action is needed to expedite birth. To minimise trauma the baby should be handled only over its bony parts (at the hip joint), and pressure or handling of the fetal abdomen should be avoided. To keep the sacrum anterior the hips can gently be held at the bony prominences of the iliac crests and the breech guided clockwise or anti-clockwise to bring the sacrum anteriorly (Figure 9.2). In the case of an extended breech, once the baby has been delivered up to the point of the umbilicus, the Pinard’s manoeuvre can be employed to safely deliver the legs. It should be noted that the knee joints are usually just at the introitus or just above when this manoeuvre would become appropriate to attempt safely, and the sacrum is kept anterior throughout. The Pinard’s manoeuvre uses one or two fingers to apply gentle pressure at the popliteal fossae in order to flex the knee, and then deliver the leg by abduction of the hip (Figure 9.3). Once the legs are delivered it is important to try and keep tactile stimulation of the baby or cord to a minimum and consider placing a towel over the baby to avoid cold stimulation. Any stimulation of the baby may result in a reflex extension of the head, which could later make the delivery of the after coming head more difficult. In addition, excessive stimulation of the skin by cold air may precipitate an in utero gasping reflex.


May 9, 2021 | Posted by in OBSTETRICS | Comments Off on Chapter 9 – Breech Delivery
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