Shoulder dystocia: Is it time to think differently?

Abstract

In the article published in this issue's edition of ANZJOG a case has been made for the procedure known as ‘axillary traction’.1 It is a procedure which has probably been used inadvertently by many clinicians when they have been unable to reach the extended posterior arm2 but also described using a plastic sling.3 The authors in the current article justifiably suggest it as an alternative procedure to internal rotation or delivery of the posterior arm. Whether or not it is proven to be better and should be advised as the primary procedure is still open to debate. The article does highlight though the issues that need to be addressed if there is to be further improvement in the management of shoulder dystocia (SD). In particular, the article emphasises the lack of consistency in the definition and diagnosis of SD and the bigger problem of lack of quality information. The authors go as far as stating that ‘even when a proforma was introduced in 2010 to capture the order of the manoeuvres used and the length of time each manoeuvre was attempted it was often not completed and the methods of management were extracted from the written clinical notes.’ This statement could have been written from any labour and delivery ward (LDW) in the world. SD occurs in approximately 1% of vaginal deliveries. It may result in significant injuries for babies and mothers4 and a traumatic experience for the woman, her partner and the staff involved. The lack of a universally accepted definition of SD has hampered knowing the true incidence of SD and made appropriate management options difficult to assess. SD is difficult to predict and therefore difficult to prevent unless all women are delivered by caesarean section. Antenatal and intrapartum risk factors all have a low positive predictive value, and although SD is related to fetal birthweight, this is of limited value because fetal size is difficult to determine accurately antenatally. Most babies over 4.5 kg deliver without SD and some cases of SD occur in babies < 4 kg. If we cannot predict and prevent SD then we need to be better prepared to manage it when it occurs. Much effort has been made to improve training for all staff to be able to react appropriately as a labour ward team when SD occurs. Great progress has been made in establishing appropriate training programs and communicating how important they are in order to prepare clinicians for the emergency. It is essential that these are present in each LDW in order to improve the physical outcome for mother and baby, but also to recognise and improve the psychological impact it may have on the woman, her partner and the staff involved.5 Simulation training is helpful, but it is not always the manipulative techniques that are crucial in SD. It is the calmness and logical decision‐making process, individually and as a team, required during the time following delivery of the fetal head, that are crucial. Those skills are difficult to teach and develop, and often only obtained by being present at actual SD deliveries. The fact remains though that in most LDWs, certainly from the medical point of view, it is the less experienced staff who most frequently have to deal with SD.5 This needs to be recognised and taken into account when trying to improve SD outcomes. SD is an acute and unpredictable event. It has a timeline hopefully of less than five minutes6 and unless you are physically present in the labour ward you might not be able to either contribute or even observe the event. Experienced obstetricians are rarely constantly present on labour wards, and therefore, no one clinician has enough experience of SD in numbers to opine conclusively on the subject. The number of SDs that each clinician is involved in is directly related to the number of hours they spend physically present in the LDW. Midwives are always present in the LDW so it is more logical that they become the primary clinicians who deal with SD when it occurs. However, because of the medicolegal implications of SD, it is important that this is translated into appropriate training and also formal recognition of their role in dealing with SD.5 The definition of SD is important to standardise in each delivery unit. It needs to be as objective as possible in order to consistently record the incidence of SD, but it also has to support clinical practice and be prospective not retrospective. The most common definitions used are as diverse as: after the first failed attempt at routine axial traction (RAT) needing additional obstetrical manoeuvres, a head‐body delivery interval longer than one minute, or as some have suggested, the failure of the mother to deliver the shoulders with her own maternal effort during the next contraction after the contraction that delivered the head.7 These definitions are influenced by different ‘standard practices’ during a normal delivery. In particular, whether the body is delivered immediately after the head or whether the body is delivered on the second contraction having waited for restitution of the baby's head.8 In order to influence clinical practice the definition and diagnosis of SD needs to come into effect early in the SD timeline to make sure assistance is available early; therefore, the most practical definition is when there has been one failed attempt at RAT.9 The problem becomes what is meant by ‘routine axial traction’9 and could any degree of traction in a vulnerable baby cause a brachial plexus injury (BPI) even if successful delivery ensues?7 On the other hand, if RAT is used and unsuccessful, then the same Aust N Z J Obstet Gynaecol 2019; 59: 605–607