Obstetric Emergencies

Teamwork and training

A team-based approach to obstetric emergencies is required, as multiple actions are often required simultaneously within a short time frame.

Simulation training can help prepare staff to manage rare, life-threatening emergencies. However, not all training is equal or effective. Local, multi-professional training in the clinical area (within the maternity unit) appears to be most effective and is more realistic than delivering training outside of the settings where care is delivered. Simulated scenarios enable teams to rehearse technical skills while testing the environment and systems in place in the maternity unit – for example, making sure that equipment is available and functional as well as ensuring that interactions with supporting systems (porters, laboratories and so on) are efficient.

Communication

Non-technical skills (communication, leadership and teamwork) in obstetric emergencies have consistently been identified as contributors to outcomes for mothers and babies. There is good evidence that training as a team improves these non-technical skills in real emergencies. Additional tools, such as checklists, may support effective communication. Emergency boxes or trolleys (e.g., for postpartum haemorrhage, eclampsia or sepsis), which contain all of the essential equipment required to manage an emergency in one place, enable teams to provide the correct care reliably and rapidly ( Fig. 35.1 ).

Team members should be aware that communication is often impaired under stress. It is important to declare the emergency to incoming colleagues to initiate the required actions, for example, ‘This is a shoulder dystocia’. Handing over of information in a succinct manner can be achieved using a structured format, such as SBAR ( S ituation, B ackground, A ssessment, R ecommendation), an example of which is shown in Box 35.1 .

General communication, such as the delegation of a task, should be clear, addressed to specific individuals, and acknowledged by the individual receiving the information – for example, ‘Jane, please fetch the postpartum hemorrhage (PPH) trolley’. When a team member completes a task, the individual should report back to the team leader so that the leader can maintain a ‘helicopter view’ of the emergency. Another useful tool can be ‘20 seconds to plan next 20 minutes’, in which the team members pause for 20 seconds to recap care and plan for the next 20 minutes of care.

Effective communication with the mother and her partner is essential. The psychological trauma of obstetric emergencies may lead to long-term psychiatric problems, including postnatal depression and post-traumatic stress disorder. Women are more likely to report a traumatic birth experience when they feel communication has been poor. Therefore, explanation of events as they are happening, appropriate consent, and debriefing after such experiences is vital. It may be appropriate for one of the team to be allocated the role of keeping the woman and her family up-to-date with events during the emergency; women want information similar to that shared amongst the team about their baby, their own safety and next steps. It may also be appropriate to offer an appointment for follow-up to the woman and her family some weeks after the event to discuss the events and answer any questions they may have (debriefing).

Risk assessment and preparation

Although many emergencies are difficult to predict, an appreciation of risk factors and continual risk assessment, both antenatally and intrapartum, can help with anticipation, preparation and prevention (if not of the emergency, then at least some of the consequences). For example, if a woman has had a previous SD, or other risk factors for SD such as diabetes, it is important to ensure that she has been offered an opportunity to discuss antenatally the risks, benefits and available options, including place or mode of birth. Furthermore, SD can complicate any vaginal birth; therefore, teams should be ready and able to manage it when it arises.

In obstetric emergencies, there are often two lives at stake. However, only the mother can be resuscitated directly. ‘Resuscitate the mother and you will resuscitate the fetus’ is a useful principle. A structured approach can be applied generically to the initial management of all obstetric emergencies associated with maternal compromise (e.g., maternal collapse, postpartum haemorrhage, sepsis), which is outlined in Box 35.2 .

Definition

SD is an impaction of the fetal shoulders at the maternal pelvis, occurring after the birth of the head. It is defined by the need for additional obstetric manoeuvres to assist the birth of the infant, when routine axial traction has failed to deliver the anterior shoulder. Routine axial traction is used to deliver an infant without SD. Most commonly, SD is caused by the anterior shoulder impacting behind the maternal symphysis pubis. However, it may also be caused by the posterior shoulder impacting on the sacral promontory. The incidence is in the range of 0.1% to 3% of vaginal births and is increasing.

Risk factors and prevention

A number of antenatal and intrapartum risk factors have been identified ( Box 35.3 ). However, these offer limited predictive value; 50% of SD occurs in normal-sized fetuses and 98% of large babies do not have SD. The most significant risk factor is SD with a previous birth, which increases the incidence to 12% to 17%. Therefore, all women with a previous SD should receive counselling about their birth options in the antenatal period, with discussion between caesarean or vaginal birth with the relevant risks and benefits; a Cochrane decision tool is available to guide the discussion. Induction of labour between 37 and 39 weeks for babies with an estimated fetal weight of >4 kg at term has been demonstrated to reduce the risk of SD by 40%, but with no improvement in clinical outcomes and a three-fold increase in severe perineal injury.

Recognition

There are a number of clinical signs that may precede an SD, which include:

• Slow or difficult birth of the face and chin

• Tight retraction of the head against the vulva

• Chin retraction (‘turtle-neck sign’)

• Lack of restitution of the fetal head.

However, a diagnosis cannot be made until there is failure of delivery of the anterior shoulder with routine axial traction.

Care of women with shoulder dystocia

A timely and systematic team approach is required to deliver the impacted fetal shoulder whilst also minimising the likelihood of fetal injury. Current international guidelines all recommend four basic manoeuvres, most commonly attempted in the following order, with the least invasive first:

• McRoberts position

• Suprapubic pressure

• Delivery of the posterior arm

• Internal rotation manoeuvres

These are outlined in more detail in Fig. 35.2 .

The first step is to call for help and clearly state the emergency of ‘shoulder dystocia’ to the team. It is important to document the time of delivery of the head and of subsequent management. Communicate what is happening to the parents and ask the mother to stop pushing, as further pushing increases the impaction. Lie the bed flat and bring the mother to the edge of the bed. After each manoeuvre, diagnostic traction (an attempt to deliver the shoulders) should be applied to the fetal head to see if the manoeuvres have successfully released the impaction. All traction should be in an axial direction (in line with the axis of the fetal spine) with the same amount of traction as for a routine vaginal birth without SD, to prevent brachial plexus injury ( Fig. 35.3 ).

The McRoberts position optimises the diameter of the pelvic inlet. It is the least invasive manoeuvre, with success rates of up to 50%. Therefore, it should routinely be attempted first. With the mother lying flat, an assistant on each side should hyperflex the mother’s legs against her abdomen. When the manoeuvre is executed correctly, the maternal buttocks should lift off the bed ( Fig. 35.4 ). All-fours McRoberts , positioning the mother in a flexed all-fours position with thighs against the abdomen, can also be attempted.

Suprapubic pressure (SPP) (1) can be applied with McRoberts and reduces the fetal shoulder-to-shoulder diameter with (2) rotation of the shoulders away from the narrowest, anteroposterior pelvic diameter. An additional assistant should apply pressure suprapubically, with outstretched arms and inter-clasped hands in a ‘CPR’ (cardiopulmonary resuscitation) position ( Fig. 35.5 ), ideally applied from the side of the fetal back. There is limited evidence as to whether rocking or continuous pressure is more effective.

Episiotomy will not relieve the bony obstruction of SD and can be difficult to perform after delivery of the head. Therefore, perform or extend an episiotomy only if there is not enough space to perform internal manoeuvres.

Internal manoeuvres include (1) delivery of the posterior arm to reduce the diameter of the shoulders and (2) internal rotation to move the shoulders away from the narrow anteroposterior pelvic diameter. Both are performed with the insertion of the accoucheur’s hand posteriorly into the sacral hollow at 6 o’clock, including the thumb, with the hand in the position of putting on a bangle ( Fig. 35.6 ). Once access has been gained, the most appropriate manoeuvre can be attempted first, depending on whether the fetal hand and forearm can be felt. If the forearm of the posterior fetal arm can be grasped, deliver the posterior arm. If not, move on to attempt internal rotation by applying pressure on the anterior aspect of the posterior shoulder, with SPP in the same rotational direction; internal rotation applies pressure to the front of the posterior shoulder and enhances the effect of SPP in rotating the anterior shoulder away from the anteroposterior pelvic diameter. If the initial round of manoeuvres fail to release the impacted shoulder, repeat the sequence.

Other manoeuvres – including (1) Symphysiotomy, division of the symphysial joint with scalpel to increase the pelvic diameter ( Fig. 35.7 ), and (2) the Zavanelli manoeuvre, replacing the fetal head in the uterus and then birth by caesarean – are ‘last-resort’ measures, associated with poor outcomes, and should be used only in extremis.

Complications

The umbilical cord can be occluded between the fetal trunk and the maternal pelvis, leading to rapid fetal hypoxia that may lead to brain injury and death. Studies have demonstrated low rates of hypoxic ischaemic encephalopathy (HIE; see Chapter 43) when the head-to-body interval is less than 5 minutes. However, it is not possible to recommend an absolute time limit for the management of SD. There are new data from the United States that neonatal fluid resuscitation may be useful for infants who are difficult to resuscitate post-SD, probably due to hypovolaemia post–cord occlusion.

Excessive traction, downward traction, and rapid application of force (jerking) are all associated with neonatal injury, particularly permanent injury to the anterior brachial plexus. Brachial plexus injury occurs in 2.3% to 16.0% of SD cases ( Fig. 35.8 ). Most are temporary, but 10% of will be permanent (>12 months), leading to life-long disability of the upper limb. Neonatal fractures of the humerus and clavicle may also occur as well as maternal complications, such as genital tract trauma and postpartum haemorrhage.

Complications relating to SD are one of the biggest areas of litigation in obstetrics. Training, accurate documentation, a systematic approach to the manoeuvres and avoidance of excessive traction have been associated with significant reduction of fetal injury, particularly permanent brachial plexus injury.

Definition

‘Cord presentation’ is defined as the presence of the cord between the presenting part of the baby and the membranes prior to membrane rupture. ‘Cord prolapse’ refers to the same situation after membrane rupture, in which the cord descends through the cervix. The cord can remain alongside the presenting part (occult prolapse) or can pass the presenting part (overt prolapse), when it will be palpable in the vagina or visible at the introitus ( Fig. 35.9 ). Cord prolapse is a time-critical obstetric emergency due to the high chance of complete occlusion of blood flow to the baby before birth.

Epidemiology

The incidence is related to fetal presentation ( Table 35.1 ). Antenatal risk factors include high presenting part, multiparity, breech presentation, unstable lie, polyhydramnios, fetal congenital abnormalities, external cephalic version and a small (e.g., small-for-gestational-age or pre-term) fetus. Intrapartum risk factors include amniotomy, internal podalic version and disimpaction of the fetal head during rotational assisted vaginal birth.

Clinical features/investigation

Early diagnosis is crucial. There are two potential insults during a cord prolapse, both of which may lead to cessation of fetal blood flow and fetal death. First, there is direct cord compression by the fetal head or body against the maternal pelvis. Second, there can be cord vasospasm from exposure to the cool external atmosphere and/or excessive handling of the cord.

Cardiotocography (CTG) usually indicates fetal compromise in the form of deep variable decelerations or a fetal bradycardia ( Fig. 35.10 ).

The cord may be clearly visible, protruding through the vagina (‘overt’ cord prolapse), or may be identified at a vaginal examination carried out in response to a CTG abnormality (‘occult’ cord prolapse). It is important to routinely exclude cord prolapse during every vaginal examination but especially following artificial rupture of the membranes or when there is a sudden change in fetal heart rate, for example, bradycardia.

Care of women with cord prolapse

Duration is critical; there is significant correlation between bradycardia-to-delivery interval and cord arterial pH in umbilical cord prolapse with fetal bradycardia. Structured management and training have been associated with improved neonatal outcomes by reducing the duration of the hypoxic insult of the cord prolapse.

First, declare the emergency and call for help. Then, relieve pressure on the cord by manually elevating the presenting part. This can be done by:

• Digital elevation of the presenting part

• Maternal positioning through exaggerated lateral recumbent or the knee–chest position ( Fig. 35.11 )

  

• Bladder filling with a catheter

Bladder filling is a useful approach when transferring a woman from a setting where immediate birth is not possible, for example, from a primary birthing centre to a hospital with facilities for operative birth. Bladder filling can be achieved by inserting a Foley catheter and filling the maternal bladder with 500 mL of fluid – tubing from a ‘blood-giving set’ can be used for this. The catheter can be clamped, which can relieve the pressure on the cord, with the filled bladder displacing the fetal presenting part upwards. If loops of cord are outside the vagina, a gentle attempt can be made to replace them within the vagina to reduce vasospasm. A dry pad can be used to keep the cord inside the vagina, without further handling the cord.

It is important to plan for immediate birth or transfer. Continuous monitoring of the fetal heart rate should be undertaken if in hospital and intravenous (IV) access should be secured. A tocolytic (e.g., terbutaline 250 μg subcutaneously) can be considered to minimise uterine contractions and related pressure on the cord.

Birth should be achieved by the quickest safe means, dependent on the fetal heart rate and gestational age. If the cervix is fully dilated, preparation can be made to expedite the birth by forceps or ventouse; if not fully dilated, preparation should be made for immediate (i.e., ‘category 1’) caesarean section. Regional anaesthesia can be considered depending on the fetal and maternal condition. A neonatologist should be called to attend. Post-birth, it is important to take paired umbilical cord gases, ensure clear documentation and debrief the mother and birth partner.

When declaring a cord prolapse, it is important to establish the fetal heart rate. The absence of palpable cord pulsation does not necessarily indicate fetal death, particularly if the prolapse is acute. Where there is doubt, particularly after a transfer, the fetal heart rate should be visualized directly by ultrasound before proceeding to caesarean. If fetal death has occurred, sadly there is no longer an urgent need to expedite birth, and aiming for a vaginal birth can be considered.

Outcomes

Despite increased access to operative birth and improvement in neonatal intensive care, the fetal mortality related to cord prolapse remains around 10%.