Imminent Birth PDF

Imminent Birth By Gayle McLelland OVERVIEW In 2017 in Australia, 1974 women or 0.7% of all births were unplanned births before arrival (BBAs) at hospital, for which paramedics could potentially have been the initial primary health provider (Australian Institute of Health and Welfare 2019). While the number of BBAs remains low, since 1991 it has almost doubled in some areas (McLelland et al., 2011). Most of the births encountered by paramedics are normal vertex presentations and require minimal intervention (McLelland et al., 2013; McLelland et al., 2018). Close to two-thirds of BBAs happen prior to arrival of paramedics, with 66% of women identified to be in the second stage of labour delivering prior to arrival at hospital. Most were clinically uncomplicated (McLelland et al., 2018). Although rare, paramedics may encounter potentially life-threatening obstetric emergencies including breech birth, shoulder dystocia and cord prolapse (McLelland et al., 2013; McLelland et al., 2018). The most frequent maternal complication at an unplanned birth is postpartum haemorrhage occurring in 6.2–6.5% of all BBAs (McLelland et al., 2013). Admissions to special care units are 2 (Beeram et al., 1995) to 6.25 (Rodie et al., 2002) times greater for BBAs than for in-hospital births. Introduction Labour is the process that enables expulsion of the fetus, placenta and membranes through the birth canal. Normal labour is the spontaneous onset of contractions that occurs between 37 and 42 weeks’ gestation and is completed within 18 hours with the presentation of the baby in a head-ﬁrst or cephalic presentation. Labour, and the eventual birth of a baby, is a harmonious balance between correct anatomy, precise physiology and the mechanics of the baby travelling through the pelvis. Often referred to as the '5Ps’—passage, passenger, powers, psychology and problems (White et al., 2011)—a successful birth requires the right combination of all of these factors. Physiology Although labour is physiologically a continuous process, for educational and clinical purposes it is divided into three stages (Pairman et al., 2014). The ﬁrst stage involves the onset of painful contractions causing eﬀacement and dilation of the cervix; the second stage starts after the cervix has fully opened and lasts until the birth of the baby; and the third stage involves delivery of the placenta (Pairman et al., 2014; Rankin, 2017; see Tables 54.1 and 54.2). The factors that initiate labour are not fully understood but it is widely accepted that it commences due to a combination of fetal, placental and maternal factors (Coad & Dunstall, 2011; Fraser & Cooper, 2009; Rankin, 2017). Table 54.1 The three stages of labour Source: Coad & Dunstall (2011); Fraser & Cooper (2009); Pairman et al. (2014); and Rankin (2017). Table 54.2 Length of stage of labour Nulliparous (ﬁrst birth) Active ﬁrst stage Second stage Physiological third stage Active third stage Average 8 hours Up to 18 hours Within 2 hours Up to 1 hour Up to 30 minutes Parous (has previously given birth) Average 5 hours Up to 12 hours Within 1 hour Up to 1 hour Up to 30 minutes Source: National Institute for Health and Care Excellence (2017). The female pelvis or passageway The human pelvis consists of four bones. The posterior wall comprises the sacrum and the coccyx bone; and the lateral and anterior walls consist of three fused bones: the ilium, the ischium and the pubis. These bones join to form a border around an empty space, which in females allows the passage of the baby through the pelvis (Pairman et al., 2014; Rankin, 2017). This passage can be divided into three zones: the pelvic brim, the pelvic cavity and the pelvic outlet. The pelvic brim separates the upper ﬂare of the iliac fossa, or false pelvis, from the lower basin-shaped true pelvis. The pelvic cavity is the area of the pelvis between the pelvic brim and the outlet. It is bordered anteriorly by the symphysis pubis and pubic bones; laterally by the interior of ilium and the body of the ischium; and posteriorly by the sacrum. The obstetric pelvic outlet is the lower portion of the pelvis and is bordered by the lower edges of the symphysis pubis anteriorly, the sacrum posteriorly and the ischial tuberosities laterally. The female pelvis is generally wider and shallower than the male pelvis and is categorised into one of four diﬀerent shapes: gynaecoid, android, platypelloid and anthropoid (see Fig 54.1) (Rankin, 2017). While the gynaecoid pelvis is thought to be ideal for childbirth, a woman may have any one of the four shapes or a combination of two or more shapes (Coad & Dunstall, 2011). The dimensions of each type of pelvis vary greatly, but the gynaecoid pelvis is the widest (see Table 54.3). Table 54.3 Pelvic measurements of gynaecoid pelvis Source: Rankin (2017). FIGURE 54.1 The four types of female pelvis. Source: Pairman et al. (2014). The fetal head or passenger Equally important in the passage of the baby through the pelvis is the size, shape and position of the baby's head. Due to the large brain, the fetal head is comparatively large for the human pelvis but with the skull ﬂexed on the neck the smallest diameter presents to the pelvis (Rankin, 2017). The passage is optimised further by the pliable nature of the baby's skull. While the facial and base of skull regions are almost completely ossiﬁed by birth, the cranium bones are not completely joined. The ﬁve large bones (two frontal, two parietal and one occipital) and two smaller bones (two temporal) that form the cranium (or vault) are connected with membranous sutures with fontanels where two or more bones meet (Rankin, 2017). The sutures and fontanels facilitate small movements between the bones, which enable them to overlap: the change in the shape of the skull assists with the baby's journey through the pelvis (Coad & Dunstall, 2011). Labour First stage The release of prostaglandins and the hormone oestradiol allows the cervix to soften and stretch, or dilate. The cervix will eventually form part of the birth canal. As the cervix changes, there are also changes in the muscle of the uterus, the myometrium. The tone of the myometrium changes to allow the coordinated contractions from the top, or fundus, increasing uterine pressure (Coad & Dunstall, 2011; Rankin, 2017). Once labour is initiated, a positive feedback loop known as Ferguson's reﬂex commences and will not ﬁnish until the birth of the baby (see Fig 54.2). Ferguson's reﬂex describes the increase in the production of oxytocins caused by the pressure of the presenting part of the baby on the cervix. This increase in oxytocins stimulates the myometrium to contract more strongly, longer and with more frequency, which in turn causes thinning and dilation of the cervix (see Fig 54.3). FIGURE 54.2 Positive feedback loop during labour. ACTH = adrenocorticotrophic hormone; CRH = corticotrophinreleasing hormone; DHEA-S = dehydroepiandrosterone sulfate; PGs = prostaglandins. Source: McLean & Smith (2001). FIGURE 54.3 Friedman's curve, a typical graph depicting the progress of labour where cervical dilation is plotted against time. The curve is divided into latent and active phases, with the active phase further divided into acceleration, maximum slope and deceleration. Source: Pairman et al. (2014). The upper and lower segments of the uterus work together during contractions. With each contraction the myometrium constricts, causing the upper segment of the uterus to descend as the baby moves through the birth canal, further strengthening Ferguson's reﬂex. During the ﬁrst stage contractions occur somewhat irregularly up to 20 minutes apart, becoming more frequent until they are 3 minutes apart. The duration of contractions is typically brief at the start (10–15 seconds) but will increase up to 1 minute by the end of this stage (Coad & Dunstall, 2011; Rankin, 2017). As the labour progresses the lower segment of the uterus stretches and the cervix continues to thin or eﬀace until there is full dilation. During the stretching of the lower segment, a membrane (the chorion) separating the baby from the mother detaches from the surface of the uterus and traps a small sack of amniotic ﬂuid between the baby's head and the cervix. This is called the forewaters. The hindwaters is the remainder of the ﬂuid behind the baby. As the cervix dilates, the pressure in the forewaters increases until they burst into the birth canal. While the membranes can rupture at any time during or even before labour, the physiological moment is when the cervix is fully dilated and entering the second stage. Towards the end of the ﬁrst stage, as the cervix dilates g g g quickly, the woman may have a bloody mucosal vaginal loss or a 'show’. During pregnancy the cervix forms a mucus plug called the operculum, which assists in protecting the uterus from ascending infection (Rankin, 2017). Expulsion of the operculum at the end of pregnancy is known as a 'show’ and often signiﬁes changes to the cervix. The mucus plug or 'show’ often continues to be expelled during labour as the cervix is dilating. Unfortunately, a 'show’ is not a reliable indicator of time to birth, as a woman can have a 'show’ at any stage during or prior to labour. Although the woman's body is preparing for labour in the ﬁnal weeks of pregnancy and she may experience some discomfort, the actual deﬁnition of labour is the onset of painful regular contractions until full dilation of the cervix. The process of eﬀacement is illustrated in Figure 54.4 and the cervix usually eﬀaces and dilates faster in women who have previously had a baby. FIGURE 54.4 Cervical dilation for primigravida and multigravida. Source: Pairman et al. (2014). The ﬁrst stage of labour can be divided into three phases: latent (early), active and transitional. The latent phase is the period from the commencement of cervical eﬀacement (thinning) and dilation until it is 3 cm dilated. The contractions commence irregularly at 15–20 minutes apart and may last up to 30 seconds but they become more coordinated and closer together. Once the cervix is more than 3 cm dilated, the active phase starts and continues until the cervix is 8–9 cm dilated. Dilation is much more rapid in the active phase, with the cervix dilating at an average of 1.5 cm per hour (Rankin, 2017). In addition, the contractions become more regular: three occurring in 10 minutes and lasting up to 60 seconds. When the cervix is 8–9 cm dilated, the woman enters the transitional phase. During this period the rate of dilation often slows and there may be a brief lull in uterine activity (Fraser & Cooper, 2009). During transition the woman often experiences restlessness and may become distressed, demanding pain relief. Second stage The second stage of labour is much shorter than the ﬁrst; it begins at full dilation of the cervix and lasts until the birth of the baby. It can last up to 2 hours in a primigravida and 1 hour in a multigravida but can be as short as 5 minutes (Rankin, 2017). Since the length of this stage varies between women the best practice is to allow each woman to follow her own urges. The woman may have short 5–6-second pushes during one contraction or she may have the desire to bear down for longer (Coad & Dunstall, 2011; Rankin, 2017). Forcing her to push without the desire or stopping her from pushing when she needs to may cause hypoxia to the baby or exhaustion in the mother (Coad & Dunstall, 2011; Rankin, 2017). At the commencement of the second stage the contractions become less intense as the mother experiences a quiet period or lull as the baby's head descends into the vagina. This can last between 10 and 30 minutes. During this important period there is no need to force the mother to push until she has the desire to do so herself (Rankin, 2017). As the baby descends further and the head becomes visible, the second stage progresses to an active period when the woman has an increasing urge to push or possibly defecate (Rankin, 2017). With each contraction the woman will bear down and the baby moves forwards and rotates in accordance with the pelvic ﬂoor. When the contractions subside it is possible that the baby may retreat back up the vagina until the next contraction (Coad & Dunstall, 2011). As the baby descends further, the perineum starts to stretch to allow passage of the baby's head (refer to the mechanism of labour below). When the widest part of the baby's head stretches the vulva to its maximum, the head often remains stationary or is said to be crowning. At this point the severity of the pain can cause the woman instinctively to stop pushing as she takes a quick breath or pants. This natural reﬂex prevents rapid delivery of the head, which could cause trauma to the perineum (Coad & Dunstall, 2011). The baby is born facing the maternal anus but will rotate as its head realigns with the rest of the body in the pelvis (restitution). After restitution, the baby continues to turn a complete 90° until its head is perpendicular with the maternal midline as the anterior shoulder rotates in the pelvis. Rotation of the anterior shoulder continues as it follows the curve of the pelvis until it exits the vagina and the posterior shoulder immediately follows. With the birth of the comparatively large head and shoulders, the baby's body is instantly born with a gush of the amniotic ﬂuid of the hindwaters (Coad & Dunstall, 2011). Mechanism of labour The journey of the baby into and through the pelvis is often referred to as the mechanism of labour. The successful completion of the mechanism of labour relies on two independent factors: the shape and the size of the presenting part of the fetus (Pairman et al., 2014; Rankin, 2017). Regardless of the orientation of the fetus in the uterus prior to delivery, there are three common principles to the mechanism: 1. the fetus will descend; 2. the leading part of the fetus will meet resistance against the pelvis ﬂoor and then rotate forwards; and 3. the last emerging part of the fetus will rotate around the pubic bone. Normal labour requires that the baby is in a longitudinal lie and that the a itude is one of good ﬂexion so that the occiput is the presenting part, as detailed in Figure 54.5. FIGURE 54.5 Mechanism of labour. Source: Pairman et al. (2014). The stages of delivery are outlined below and in Figure 54.6. FIGURE 54.6 The stages of delivery. Descent Often the descent of the fetal head into the inlet of the pelvis occurs in the ﬁnal weeks of pregnancy, especially for a primigravida. It is possible that the head will not descend until after the commencement of labour for a multigravida. As labour progresses the fetal head descends into the pelvis in transverse diameter but ease of entering the pelvis is largely reliant on the a itude or ﬂexion of the fetal head (Pairman et al., 2014; Rankin, 2017). Flexion The force of the contractions on the fetal spine forces ﬂexion of the fetal head as it enters the pelvis. This facilitates the presentation of the least possible diameter of the fetal head (Pairman et al., 2014; Rankin, 2017). Internal rotation Due to the force of the contractions and the shape of the pelvis, including the ischial spines, once the fetal head has completely entered it rotates so that it lines up with the anteroposterior diameter of the pelvic outlet. The occiput has now moved forwards and is lying under the symphysis pubis. The position of the neck is slightly changed so that the head is no longer aligned with the shoulders (Pairman et al., 2014; Rankin, 2017). Extension of the head As the head moves under the pelvic arch it swivels on the pubic bone and pushes through the vagina, causing it to extend upwards. The forehead, face and chin then pass across the perineum (Pairman et al., 2014; Rankin, 2017), as illustrated in Figure 54.7. FIGURE 54.7 The head rotating and descending in the second stage. Source: Marshall & Raynor (2014). Restitution With the birth of the head, the shoulders enter the pelvis. The head appears to turn slightly externally as it realigns itself with the shoulders. External rotation (shoulders) As the shoulders continue to enter the pelvis, they align themselves with the anteroposterior diameter. The anterior shoulder hits the pelvic ﬂoor and moves under the symphysis pubis. This causes the head to continue to rotate so that the baby faces either the woman's left thigh or her right thigh. After the birth of the anterior shoulder, the posterior follows as it passes the perineum. Third stage The birth of the baby marks the commencement of the third stage. The contractions change and the rate slows (Pairman et al., 2014; Rankin, 2017). This stage can last between 5 and 60 minutes and is a vulnerable time for the mother as she has an increased risk of haemorrhage during this period (Coad & Dunstall, 2011). After the birth of the baby the uterus contracts down upon itself; this reduction in size reduces the surface area of the placental site. The veins become more congested and rupture, causing the ﬁrm placenta to buckle and detach from the more ﬂexible myometrium. The continuing contraction of the uterus causes the oblique muscle ﬁbres to constrict around the blood vessels supplying the placenta, preventing drainage of blood back into the maternal system (see Fig 54.8). The increasingly congested placenta usually detaches from a central point and its escalating weight forces the separation of the edges followed by the membranes (Coad & Dunstall, 2011; Pairman et al., 2014; Rankin, 2017S. Thus with the continuous contraction of the uterus and the weight of the placenta, the membranes are stripped from the uterine wall. Signs that the placenta is about to deliver are a small gush of blood (separation) and the appearance of the cord lengthening (descent). FIGURE 54.8 The third stage of labour commences after delivery, A. The uterus contracts and the placenta separates, B, and eventually passes down the birth canal, C. Source: Marshall & Raynor (2014). With the separation of the placenta, there is an increased risk of bleeding as blood continues to ﬂow to the placental site. Three mechanisms assist with the control of blood loss at this stage: 1. the 'living ligatures’ or muscle ﬁbres constrict around the blood vessels that previously connected the uterus to the placenta; 2. vigorous contraction of the upper segment of the uterus eﬀectively applies pressure to the placental site; and 3. temporary changes in the clo ing factors allow a ﬁbrin mesh to form over the damaged veins and then quickly form over the placental site (Rankin, 2017). Management of the third stage can be either physiological (allowing the process to occur naturally) or active (administering medications and therapy). It has generally been thought that active management helps prevent postpartum haemorrhage (Fraser & Cooper, 2009; Rankin, 2017) but recent research has questioned this belief (Pairman et al., 2014). At present, physiological management is recommended only for low-risk births but this presents a challenge in the pre-hospital se ing as—purely by deﬁnition—out-of-hospital births are considered high risk in that they always occur in an unplanned se ing, without the expected continuity of care, and often are precipitated births. However, most births that occur in the out-of-hospital se ing are in fact normal vertex presentations and require li le or no intervention (McLelland et al., 2018; Moscovi et al., 2000; Verdile et al., 1995). As such, paramedics should be conﬁdent that physiological management should be adequate in most cases. In fact, in practical terms there are no in-ﬁeld options for management of the third stage except allowing the placenta to separate and deliver naturally. The gush of blood that accompanies this may seem dramatic but if palpation reveals a ﬁrm uterus (a li le bigger than a cricket ball), paramedics can be reassured that there should be no further bleeding from the placental bed. PRACTICE TIP For the paramedic who may occasionally be involved with obstetrics, the key point in the physiology of normal delivery is that it all occurs automatically without any need for intervention. Maternal physiological adaptation during labour Cardiovascular system A progressive rise in cardiac output with each contraction adds 300–500 mL of blood to the circulating volume and increases the woman's heart rate (Coad & Dunstall, 2011; Pairman et al., 2014; Rankin, 2017). There are also increases in diastolic and systolic blood pressure: increasing 5 seconds before a contraction and returning to baseline after the contraction. In the ﬁrst stage, there may be a rise of 35 mmHg systolic and 25 mmHg diastolic; and in the second stage the diastolic can rise up to 55 mmHg and the systolic can rise higher than in the ﬁrst stage (Coad & Dunstall, 2011; Pairman et al., 2014; Rankin, 2017). With the delivery of third-stage dramatic haematological changes occur and parameters return to pre-labour levels (Coad & Dunstall, 2011; Pairman et al., 2014; Rankin, 2017). Supine hypotension remains a risk during labour, with the pregnant uterus pressing on the inferior vena cava and causing a reduction in cardiac return (Coad & Dunstall, 2011; Pairman et al., 2014; Rankin, 2017; see Fig 54.9). As a guiding principle, paramedics should avoid allowing a pregnant woman to lie supine. In transit this means using either the left lateral position or a wedge under the right hip to tilt the pregnant uterus away from the vena cava. Unfortunately, most ambulances have a stretcher mounted on the right side of the vehicle so the paramedics have to turn the patient away from them, making observations that much harder. Loading the woman feet ﬁrst is a possible solution but it removes the paramedic's ability to sit at her head and manage her airway or to secure her using the appropriate safety restraints. FIGURE 54.9 Supine hypotension. The weight of the gravid uterus can compress the inferior vena cava when the patient is supine, A. This can be managed by tilting the patient at least 30° to the left, B, or manually displacing the uterus to the left, C. Source: Pairman et al. (2014). Haematological system To keep blood loss during delivery to a minimum, changes occur in the haematological system, including a state of increased coagulation (this precedes and follows delivery by several weeks) and physiological anaemia as a result of the increase in blood volume (increased plasma volume) but not in the amount of red blood cells. During labour, however, haemoconcentration can occur as a result of dehydration from exertion. Stress and muscular activity can also precipitate an increase in the formation of red blood cells (erythropoiesis). During labour and immediately postpartum, there is an increase in neutrophils and the white cell count may increase up to 25–30 × 109/L (Coad & Dunstall, 2011; Pairman et al., 2014; Rankin, 2017). Respiratory system In active labour, hyperventilation from pain or anxiety can lead to a temporary respiratory alkalosis with the typical signs of hyperventilation (peripheral paraesthesia). A respiratory acidosis can occur if contractions are too close together (unlikely in spontaneous-onset labour) or if the woman holds her breath too long when pushing during the second stage (Coad & Dunstall, 2011; Rankin, 2017). Both conditions are generally self-resolving and do not require any intervention. However, both may indicate inadequate pain relief. Renal system Increased aldosterone secretion stimulates an increase in sodium loss (and potassium retention). There is a chance of dehydration so ﬂuid intake should be maintained, particularly in prolonged labour or in labour occurring in hot conditions (Coad & Dunstall, 2011; Rankin, 2017). CASE STUDY 1 Case 10923, 1036 hrs. Dispatch details: A 37-year-old woman, 39 weeks’ gestation; membranes have ruptured; in labour. Initial presentation: On arrival at the scene the paramedics ﬁnd the patient leaning over the couch in her lounge room. She is able to answer questions in between contractions. Her neighbour is in a endance as they are unable to contact the patient's husband, who has gone to a country town for work. He is out on site, so is unreachable at the moment. The woman's 3-year-old daughter is also present. ASSESS Patient history On questioning the patient tells the crew that her membranes ruptured an hour ago and the amniotic ﬂuid was clear. She is having contractions every 6–8 minutes but at this stage can breathe through them. She does not report an urge to push. This is her ﬁfth pregnancy: three of her children are at school and one is with her. In order to prepare a treatment plan the crew need to know: the history of this labour the history of this pregnancy the history of previous pregnancies and births a general medical history. This labour When did the contractions start? How often are they coming? It is possible in this situation that a woman may be so distressed that she may state she is feeling contractions long after they ﬁnish, so the paramedics should try to feel the contractions if they can (see Fig 54.10). FIGURE 54.10 Feeling for a contraction. Source: Pairman et al. (2014). Have the membranes ruptured? The membranes can rupture at any point before or during labour, even when the head is crowning. If the membranes are still intact when the head delivers, they need to be ruptured manually by tearing them. The membranes must not be ruptured manually if they cannot be visualised. Once the membranes have ruptured, the amniotic ﬂuid should be clear to slightly pink in colour. Any other colour is signiﬁcant: green to brown could indicate a distressed baby and any shade of red could indicate bleeding. Is there any other vaginal discharge? Mucus mixed with a small amount of blood, or a 'show’, indicates normal detachment of the membranes as the cervix is dilated. If the mucus becomes more heavily blood-stained, it may indicate that the cervix is nearing full dilation. Any amount of frank bleeding should be considered abnormal. When did the mother feel the baby move last? Paramedics have no ability to monitor the baby's wellbeing or health and asking about movements provides only an indication about the baby's health. Babies do not continually move in utero and often have 'sleep periods’ where they are very quiet, so a lack of movement does not necessarily indicate a problem. If the mother has had a trouble-free pregnancy and is at term, and the labour is spontaneous and trouble-free, there is no reason to think there is a problem. Are there any signs of the second stage or imminent delivery? For example, uncontrollable urge to push, anal pouting, perineal bulging or presenting part on view. When did the mother last void? It is important to ask when the woman last urinated to assess ﬂuid status, as dehydration can slow the progress of labour and a full bladder can become an obstruction during the second stage of labour (Pairman et al., 2014). This pregnancy What is the mother's gravida and parity? Generally, if a woman is a nullipara, the labour will take longer than if she is a multigravida (Pairman et al., 2014). However, there are exceptions to any rule so paramedics should always assess the woman's physical and clinical signs. What is the gestation in weeks? Rather than asking the baby's due date, it is be er to ask the gestation in weeks. Determining the gestation of the baby allows the paramedics to assess the risk associated with a premature infant (see Ch 55). Have there been any obstetric complications during the pregnancy? Complications such as pre-eclampsia, gestational diabetes or antepartum haemorrhage can assist in gauging the risk of associated intrapartum or postpartum complications (Coad & Dunstall, 2011; Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017). Previous pregnancies and births Has the mother had any previous pregnancies and births? Were there any complications? Women who have pregnancy and birth complications may be at greater risk of similar complications with subsequent pregnancies. Paramedics should assess the potential risk for this birth by obtaining a thorough history of previous births and pregnancies, such as shoulder dystocia, breech presentation and postpartum haemorrhage. Past or present medical history Does the woman have any chronic medical conditions? For example, asthma, cardiac conditions. Is there any acute exacerbation of chronic medical conditions? Has the patient had any recent acute medical conditions? For example, upper respiratory tract infection, urinary tract infection. Does the patient have any allergies? Initial assessment summary! Problem Conscious state Position Heart rate Blood pressure Skin appearance Speech pa ern Respiratory rate Respiratory rhythm Chest auscultation Pulse oximetry Temperature Pain History Physical assessment Labour GCS = 15 Standing 92 bpm 125/70 mmHg Pink, warm, dry Normal between contractions 18 bpm, becomes more erratic during contractions Even cycles Good breath sounds bilaterally 99% 37.4°C Li le to no pain between contractions; 8/10 during contractions Gravida 5, para 4. Her membranes ruptured an hour ago and the amniotic ﬂuid is clear. She is having contractions every 6–8 minutes but at this stage is able to breathe through them. She does not report an urge to push. Her last labour was over in less than 4 hours. No signs of the second stage of labour. D: There are no immediate dangers. A: The airway is not compromised. B: Breathing is normal. C: The patient is well perfused and there is no obvious haemorrhage. The patient is a multigravida presenting in the ﬁrst stage of labour of a near full-term uncomplicated pregnancy. Previous vaginal deliveries were uneventful and she has no complicating medical conditions. There does not appear to be any sign of fetal distress. CONFIRM The challenge facing the crew is this situation is to decide whether there is time to transport the patient to hospital for the birth or whether the birth is imminent and they should prepare to deliver the baby prior to transport. Such are the uncertainties with the progression of labour that this judgment has to be made on a case-by-case basis considering the resources available, the distance to hospital and the patient's presentation. Although it is possible to deliver a baby in the ambulance it is not well-suited to the procedure and should be avoided if possible. DIFFERENTIAL DIAGNOSIS First stage of labour Or Second stage of labour and imminent delivery likely The following criteria should be assessed prior to making a decision about transport: contractions vaginal discharge signs of imminent delivery wellbeing of the baby signs of the second stage of labour and an imminent delivery. Contractions Deﬁnitive diagnosis of labour can be made only by performing a vaginal examination to assess cervical eﬀacement and dilation. This skill is not commonly within the scope of practice for paramedics, so they need to rely on clinical assessment of contractions (see Box 54.1). The onset of early labour is often signiﬁed by the commencement of irregular contractions occurring 15–20 minutely that may last up to 30 seconds. During this period paramedics may discuss options with the patient and her family regarding staying home longer or travelling independently to hospital versus being transported in an ambulance. They can explain that labour is not fully established and she has time to organise herself further. BOX 54.1 Contractions Contractions are often described as intermi ent waves of pain reaching a crescendo and then tapering, with a period of li le or no pain in between. The frequency of contractions is measured from the beginning of one contraction until the beginning of the next and is described in one of two ways: 1. by how often they come (i.e. 3 minutely, 5 minutely, 10 minutely); and 2. by how often they occur in a 10-minute period (i.e. 3 in 10 minutes, 2 in 10 minutes or 1 in 10 minutes). The length of a contraction is measured from the beginning of that contraction until the end (i.e. 20 seconds, 30 seconds, 45 seconds and 60 seconds). In normal labour contractions rarely last longer than a minute or the baby would be compromised (Rankin, 2017). With the mother's permission to feel for a contraction, the paramedic should place one hand on the uterine fundus. The abdomen will become increasingly tenser for a period of time, usually no longer than 60 seconds, and then it will relax for a period of time before becoming tense again. Each labour will have unique characteristics depending on several factors, including the number of previous babies the woman has had, the position and presentation of this baby, the gestation in weeks and whether there are other obstetric or medical complications. Labour is a dynamic process during which the contractions increase in strength, duration and frequency. A patient may describe the frequency of contractions by how many minutes apart they are but it is important that the paramedic is also aware of the length. Assessing the contractions accurately will assist in determining the appropriate form of pain relief. As the labour progresses, the contractions may come three times in 10 minutes and last up to 60 seconds. This often signiﬁes that the woman is in active labour. Even so, the birth could still be several hours away. If the patient is very distressed and demanding, it is likely that she has entered the transitional phase but that does not always rule out the opportunity to transport. In this case the patient's calm presentation, the timing of the contractions and the lack of an urge to push during the contractions suggest that birth is not imminent. Vaginal discharge Assessing the vaginal discharge during labour will assist paramedics to gauge the wellbeing of both the mother and the baby as well as assisting in decisionmaking. Vaginal discharge can include the expelled mucus plug as the cervix dilates, amniotic ﬂuid and any vaginal bleeding. In this case, the discharge appears normal and does not indicate any urgency. Signs of imminent delivery As the second stage can take up to an hour to complete, there is often enough time to transport the patient to hospital but paramedics should consider the circumstances in which they have been requested. Most mothers have a plan for the birth and requesting an ambulance may suggest that events are occurring faster than anticipated, which could indicate a rapid progression of labour. An uncontrollable urge to push or bear down, uncontrollable grunting and an urge to defecate should all be considered as imminent signs of birth. As the baby descends through the pelvis, this will progress to anal pouting or puckering, perineal bulging and the presenting part becoming visible. It is worth noting that the rate of progression can slow or even halt and concurrent preparation for transport is always advisable. More often than not, the births that paramedics a end progress quickly and may require the paramedics to support the mother through the birth. In this case there are no signs of imminent delivery. The baby's wellbeing One of the key assessments of fetal wellbeing is to monitor the fetal heart rate (FHR) through labour and especially in relation to the contractions. Paramedics do not commonly have the equipment to monitor the FHR, however, so assessing fetal wellbeing is diﬃcult in this se ing. Enquiring about the last fetal movements provides a small amount of information about the baby's wellbeing, but babies do not continually move in utero so a lack of movement does not necessarily indicate a problem. This patient says she felt her baby kick 15 minutes before she called for the ambulance. As her membranes have ruptured and the ﬂuid appears clear, there is no suggestion that the baby is distressed. Signs of the second stage of labour and an imminent delivery While this patient's heart rate may be higher than that of a non-pregnant woman of her age, it is not unexpected in pregnancy and especially during labour. Her respiratory rate is within normal limits but respiratory hyperventilation is common in the ﬁrst stage of labour. The patient is having two strong contractions every 10 minutes and they are lasting for 50 seconds. She is panting through the contractions and is relatively pain-free between them. The crew make the sound decision that the patient is in the active phase of the ﬁrst stage of labour and can be transported the estimated 20 minutes to hospital. PRACTICE TIP Most patients have a prearranged obstetric plan, including their hospital of choice. If the patient progresses rapidly, delivery at an alternative hospital with midwifery facilities is be er than delivery in the back of an ambulance. TREAT Emergency management Safety While the patient is in her own home, she should be allowed to remain in a position of comfort until the initial assessments and evaluations have been completed. For safety reasons, she should be transported in either a semirecumbent or a lateral position to avoid supine hypotensive syndrome. If her membranes ruptured on the ﬂoor, check that there are no slip hazards. Last micturition As the baby descends into the pelvis, the bladder is vulnerable to traumatic damage (Fraser & Cooper, 2009). In addition, a full bladder can delay the progress of the baby's head as it descends during the second stage (Rankin, 2017). Prior to transport, the paramedics should encourage the woman to pass urine, as there will be li le chance until they arrive at the hospital. Vaginal discharge A maternity pad placed at the labia will enable the crew and the receiving hospital to accurately describe and measure vaginal loss. Analgesia Regular contractions can be very painful. The possibility of not giving birth in the intended place, with the expected carers, can be extremely stressful and exacerbate the patient's discomfort (Pairman et al., 2014). If the patient requires analgesia, the use of numerical scores as an assessment tool for pain is not recommended for a woman in labour (National Institute for Health and Care Excellence, 2007). The intermi ent nature of contraction pain makes it diﬃcult to manage and fast-acting inhaled analgesics are be er suited than long-lasting IV agents such as opioids, which can have a sedative eﬀect between contractions. Opiates also cross the placental barrier and so their use in late labour risks producing respiratory depression in a newborn infant and even drowsiness for several days after birth, which can aﬀect the baby's breastfeeding (National Institute for Health and Care Excellence, 2017). When paramedics have no option but to administer an opioid analgesic, it is important that they assess the mother completely to ensure that they are satisﬁed she is not near the second stage. Philosophically, the management of pain for a woman in labour is very diﬀerent from many of the other cases paramedics manage. The woman in labour should be treated as a 'normal’ or 'well’ event not an 'emergency’ or 'ill’ event. Certainly as the out-of-hospital context is unplanned and the usual in-hospital or home birth resources are unavailable, there is some risk. But most unplanned births are uncomplicated and occur without undue incident. While paramedics cannot provide the continuity of care that has been shown to be a key element of successful progress in labour, they can provide a calm and reassuring environment for the mother. Building rapport and trust with the mother will reassure her that she is safe and is essential for delivering safe but adequate pain relief. Oxygen Physiological anaemia is commonly experienced in late pregnancy, but labour is a normal process so oxygen is not required in this situation. Although oxygen may be administered during obstetric emergencies, it is important to note that there is no recent quality evidence to support the eﬀectiveness or not of this practice (Pairman et al., 2014). Although the ﬂow of oxygen to the placenta is reduced in normal labour, the normal-term fetus adapts well by redistributing the ﬂow of blood to protect vital organs such as the heart and brain, so overall the fetal circulation is unaﬀected by the pressure of the contractions (Steer & Flint, 1999). Preparation for an emergency birth Although many of the women in labour a ended to and transported by paramedics do not actually give birth prior to arrival at hospital, it is wise for the crew to prepare for emergency birth. This includes arranging to rendezvous with another crew en route or preferably at the scene, as it can take more than two crew members to manage both the mother and the infant if problems arise. The majority of babies are born without incident, but crews should also routinely prepare the scene for neonatal resuscitation (see Ch 55). 1116 hrs: After travelling for 12 minutes, the patient becomes very distressed and commences a gu ural groaning. She tells the paramedics that she needs to push. Upon visual inspection, the paramedics notice anal pouting and perineal bulging. The decision to pull over for delivery is diﬃcult. However, the paramedics have to set up not only for delivery but also for potential resuscitation of the newborn in a very tight environment. Comfort/analgesia Often a woman feels relief when she pushes according to her own natural urges during the second stage (Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017). As well as assessing the frequency, length and intensity of the contractions, the paramedics should assess how the woman pushes during the contractions. It can be normal for a woman to have several short 5-second pushes in one contraction. The imminent signs of delivery Once the baby has descended, the bobbing of the presenting part on the perineum should be visible to the paramedics. If the rate of progression appears to halt or slow, the paramedics will need to consider recommencing transport, as this could be a sign that there may be an unexpected problem. They also need to ensure that the mother does not progress too rapidly and have an explosive birth. They can prevent this by coaching her on her breathing throughout the contractions. Provided the baby does not become stuck, the head should be delivered within a few minutes of it being visible between the labia. The paramedics want the baby's head to be delivered, but not so rapidly that it causes damage to the baby and to the perineum, hence this is the phase where they will instruct the patient to pant in an eﬀort to control the rate of delivery. Vaginal discharge The paramedics should continue to assess the colour and amount of vaginal discharge. Often, as the cervix dilates fully, a more heavily blood-stained 'show’ will be discharged. While this is normal, any frank bleeding should be considered abnormal (Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017). If the membranes have not already ruptured, they will usually rupture at the commencement of the second stage but this cannot be guaranteed (Fraser & Cooper, 2009). Fetal wellbeing As the baby descends, fetal oxygenation is threatened due to cord or head compression, so the paramedics need to continue to monitor the amniotic ﬂuid, looking for meconium staining. It is not unusual for fetal movements to be reduced or diﬃcult to detect during the second stage. Position Usually during the second stage a woman should be able to assume any position where she feels the most comfortable. Squa ing, kneeling on all fours or standing positions all produce a 28% increase in the outlet compared to supine or semi-recumbent positions. However, the back of the ambulance can be restrictive and may limit the amount of freedom the woman has, especially when moving. The birth process The paramedics should allow the mother to follow her instincts and push as she wants. There is no evidence to support the practice of instructing the mother to push (Valsalva manoeuvre) and it has been suggested that this could cause problems for both mother (Rankin, 2017) and baby (Pairman et al., 2014). Initially, with contractions the baby's head will advance and recede: this slowly stretches the perineum to allow it to accommodate the baby's head (see Fig 54.7). Once the baby's head remains on the perineum and does not recede (crowning), the mother may complain of a burning sensation as the perineum stretches. During this time, the paramedics can encourage the mother to pant to minimise the possibility of perineal damage associated with a rapid birth. While the mother is pushing, she may defecate. This is quite normal. Placing a pad over the rectum will enable the paramedics to keep the area clean. Most babies will birth spontaneously with minimal or no hands-on assistance. However, rapid descent of the head has been associated with an increase in maternal perineal tears. Lightly placing ﬁngers on the descending head can provide support in a rapid birth and prevent perineal tears (Pairman et al., 2014). However, it is important not to place too much pressure on the head so that its progress is hindered. Once the baby's head is born, there is a rest period between contractions. Traditionally at this time the baby is checked to see whether the cord is wrapped around the neck and to identify whether it needs to be cut to relieve pressure. For the mother this is an awkward procedure and many women ﬁnd it uncomfortable or even painful. Most babies birth through the cord, so cu ing the cord at this stage needs careful consideration as it will remove the only source of oxygen the baby receives and could cause further distress (Pairman et al., 2014). Paramedics should avoid cu ing the cord unless it is obstructing the descent of the baby through the pelvis. As the baby is born the paramedics should still be assessing the amniotic ﬂuid for any change in colour. With the next contraction the baby's shoulders enter the pelvis and rotate into the anterior-posterior diameter of the outlet position. This rotation of the shoulder is observed externally as the baby's head restitutes to come into alignment with the shoulders. This is a natural movement and should not be forced. With the next contraction the woman may need to be encouraged to give another push and the anterior shoulder should deliver. If it does not deliver spontaneously, the paramedic may need to apply some gentle upward traction if she is on all fours. Following the birth of the anterior shoulder, some gentle downward traction will deliver the posterior shoulder. Immediately the rest of the baby will follow. The time of birth should be noted. Care of the baby 1132 hrs: Immediate care of the baby commences (see Ch 55). One paramedic takes responsibility for the baby and the other cares for the mother. They assist the patient to roll over so that she can hold her baby. With the patient's permission, the paramedics place the baby skin-to-skin on her abdomen and they wrap both mother and baby in a blanket to keep them warm. While paramedics should not force breastfeeding, it often occurs naturally with mother and baby in this position. This will stimulate the release of oxytocin, which aids in the completion of the third stage. Many ambulance services have operating instructions requiring all patients to be secured appropriately in a moving vehicle that would (taken literally) include a newborn baby. Paramedics have to balance the very real risk of hypothermia that is easily prevented with skin-to-skin contact (in the absence of a heated cot in the ambulance) with the risk of injury associated with an ambulance crash. The birth of the baby signals the end of second stage of labour and the commencement of the third stage. The third stage Contractions/pain The uterus continues to contract after the birth of the baby, but usually this does not cause any undue distress. Rarely, a woman may experience painful 'after pains’ and require analgesia. Increasing pain could be a sign of trauma (uterine rupture, for instance) and while reassuring the patient the paramedics should be re-evaluating for any signs of peritonism. Vaginal discharge The paramedics need to check for any vaginal discharge at the end of the second stage and the beginning of the third stage. While there is a slight possibility that signs of meconium as the baby is born could indicate that the baby was stressed, it is more likely to be a normal bowel action (see Ch 55). A gush of blood can be a sign of normal placental separation, but other causes should be considered. If there is continual bleeding, especially greater than 500 mL, the paramedics should manage this postpartum haemorrhage by controlling obvious sources of haemorrhage with direct pressure and instituting volume replacement as usual. Perineal damage The perineum should be assessed for tearing or trauma and managed if required. Applying a combined dressing or maternity pad has two beneﬁts: 1. it provides pressure to arrest bleeding; and 2. it aids assessment of any further bleeding. Position For transport during the third stage the mother can assume a position of comfort. But the paramedics need to continually assess for signs of separation and descent, as they may need to stop the ambulance to deliver the placenta. The best position for delivery of the placenta is an upright position (Coad & Dunstall, 2011), which is not optimum in a moving vehicle. Last void The paramedics should document the last time the patient voided as a full bladder can delay completion of the third stage and contribute to postpartum haemorrhage (Coad & Dunstall, 2011; Pairman et al., 2014). This information will be useful to pass on to the midwifery staﬀ. Management The third stage is a vulnerable period in the out-of-hospital se ing with an increased risk of postpartum haemorrhage (Coad & Dunstall, 2011; Rankin, 2017). Crews need to weigh the beneﬁts of the physiological third stage against the possible need to manage complications. As the physiological third stage can take up to an hour, the paramedics should resume transport while continually assessing for signs of separation and descent. There is no need to pull the cord or manipulate the uterus at any time. Unless neonatal resuscitation is required or transferring the mother to the stretcher proves problematic, the cord should remain intact during transport to facilitate the physiological third stage (Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017). If the cord has been clamped or cut during the birth or before it stops pulsating, the physiology of the third stage is altered and active management is required (Pairman et al., 2014). In the out-of-hospital se ing physiological management of the third stage must be considered the most appropriate option but it depends on the circumstances. For a birth at term, leaving the cord intact until it ceases pulsation is sensible. Unfortunately, unplanned births before arrival (BBAs) at hospital have a greater risk of maternal and neonatal complications (McLelland et al., 2013) so it may not always be possible to physiologically manage the third stage. That said, true active management of the third stage can prove diﬃcult in the out-of-hospital se ing. Use of out-of-hospital pharmacology depends on the availability of the drugs and the ambulance service guidelines but may include intramuscular Syntocinon or oral/rectal misoprostol. If the ambulance service guidelines recommend pharmacology only with postpartum haemorrhage, the paramedics should be alert to the increased risk of bleeding once the umbilical cord has been cut. With good reason, many out-of-hospital guidelines (Woollard et al., 2008) advise against paramedics practising controlled cord traction, but this technique may be necessary if there is a postpartum haemorrhage (see Case study 5 and Box 54.3 later in this chapter). BOX 54.3 Controlled cord traction In the out-of-hospital se ing controlled cord traction should be undertaken only if absolutely necessary for postpartum haemorrhage and if oxytocic medication has been administered. Unless the third stage is complicated by excessive bleeding, there is no rush to deliver the placenta in the out-of-hospital se ing and so active management is not often necessary. Sometimes the mother may have a desire to push again and will spontaneously deliver the placenta. Otherwise, it is wisest to allow the placenta to remain in situ and leave management of third stage to the maternity staﬀ. If the placenta is delivered during transport, it should be placed in a plastic bag and taken to hospital. The paramedics can check that the placenta is complete but this will be done again in the maternity unit. Hospital admission Ideally, the paramedics should transport the patient to the hospital that she has booked into as it will have a record of her obstetric history and medical history, including her blood group. A common exception to this is if the baby is premature and requires a special care nursery (SCN) or neonatal intensive care unit (NICU). Other possible exceptions include that the hospital is too far away. There are a variety of models of care available to pregnant women. The patient could be under the care of a midwife or a medical practitioner such as an obstetrician. Even if the baby was born outside the hospital, the primary carer will oversee the overall management. On admission to the hospital, management will depend on the patient's condition. If the placenta has not been delivered, she will be admi ed to the birthing suite; if it has been delivered, she will be admi ed into postnatal care. Any perineal or vaginal lacerations will be repaired; and twice per day the involution of the uterus will be checked to ensure that it is descending as required and her vaginal loss (lochia) and any sutures will be checked for signs of infection. As much as possible mother and baby will remain together unless the baby needs to be admi ed to SCN or NICU. A normal, healthy term baby will room in with the mother and she will be encouraged to breastfeed as soon as possible. The length of hospital stay varies from 2 to 5 days for a normal birth. Even if the baby is in SCN or NICU, most women will be discharged within this timeframe. Investigations Any required investigations depend on the woman's condition; often, for a normal birth no investigations are required. If the mother is a negative blood group, the baby's blood group will be checked; if the baby is a positive blood group, the mother will receive anti-D within 72 hours of the birth. This will prevent the mother forming antibodies against the blood type of any subsequent babies she may carry. If the woman has suﬀered excessive bleeding, her haemoglobin and blood group will be checked. Follow-up Discharge follow-up for a normal birth is largely dependent on the model of care chosen by the woman. In the caseload model, the woman will continue to be cared for by the midwife or midwives of that team. Women not in the caseload model will be visited by the hospital domiciliary midwife for up to a week after the birth. The number of visits made depends on the length of the woman's stay in hospital: the shorter the stay, the more visits. Women in the medical model will visit their medical practitioner approximately 6 weeks after discharge. Once the woman has been discharged from the services provided by the hospital, the maternal child and health nurse will usually make at least one visit to the woman's home. Thereafter, the woman will usually go to the maternal child and health centre to have her baby's health monitored. CASE STUDY 2 Case 11121, 2245 hrs. Dispatch details: A 25-year-old female, who is 34 weeks’ pregnant, is in labour with her second child. Initial presentation: The ambulance crew ﬁnd the patient lying in a left lateral position on her bed. She tells them that she thought the contractions would stop but they have got stronger since her membranes ruptured. ASSESS 2258 hrs History: She says that her contractions started at 6 tonight and she is now having three contractions in 10 minutes. Her membranes ruptured an hour ago and the amniotic ﬂuid has been clear. She also had a show earlier in the day. Her husband does not have a driver's licence and they have no-one to drive her to hospital. She has had the urge to push during the last few contractions. This is her second pregnancy and she has had one live birth. 2300 hrs Examination: The patient has anal pouting and perineal bulging. As the paramedics prepare to assist with the birth, they observe fresh meconium when she pushes. With the next push, they realise that the presenting part is the baby's bu ocks. Breech presentation In a breech presentation the presenting part of the baby is the sacrum, foot or knee. There are four types of breech presentation (see also Fig 54.11). FIGURE 54.11 Types of breech presentation. A Complete. B Frank or extended. C Footling (kneeling). D Footling (single). Source: Pairman et al. (2014). Extended, frank or incomplete breech occurs in 45–50% of breech presentations, usually in women who are having their ﬁrst baby. The baby's thighs are ﬂexed with the legs extended at the knees so the feet lie adjacent to the baby's head. Complete or ﬂexed breech occurs in 10–15% of breech presentations, usually in women who have previously had babies. The baby's thighs are ﬂexed and crossed, with the feet close to the bu ocks. Footling breech is rare and occurs more commonly in premature births, usually before 34 weeks (Fraser & Cooper, 2009). One or both of the hips and knees are extended and the feet present below the bu ocks. Knee breech is the rarest breech presentation with one or both hips extended and the knees ﬂexed, presenting below the bu ocks. The proportion of breech presentations decreases as the gestational age of the baby increases, from 25% at < 28 weeks’ gestation to no more than 10% at 34 weeks’ and 1–3% at term (Pairman et al., 2014). Risk factors for a breech presentation include: extended legs in utero multiple pregnancy preterm labour polyhydramnios hydrocephaly uterine abnormality placenta praevia (Pairman et al., 2014). There are no deﬁnite warning signs to diagnose a breech but often breech births are preceded by fresh or thick meconium after the membranes rupture (Royal Women's Hospital, 2006). Due to compression of the abdomen as it passes into the pelvis the baby often passes meconium. This is not a sign of fetal distress unless it occurs in early labour (Fraser & Cooper, 2009). In early labour the meconium will be blended more with the amniotic ﬂuid to give it a brownor green-stained appearance that occurs with fetal distress. TREAT Breech delivery has its own speciﬁc problems associated with the timely delivery of the baby before hypoxia causes damage. Because the widest part of the baby is following and not leading, there is a concern that the baby may become stuck. However, a minimalistic hands-oﬀ approach is best unless the progress of the birth is impeded: intervention is rarely required (Pairman et al., 2014). All other aspects of the delivery and at the resuscitation are similar to the normal situation. When the perineum is distended by the bu ocks, the paramedics should place the woman in the lithotomy position with her bu ocks at the edge of the bed or couch and her legs pulled back at a 90° angle by either herself or two bystanders. Consider using dining chairs or other furniture for her to rest her legs (Woollard et al., 2008). The paramedics should observe the bu ocks as they progress through the perineum. The breech should rotate spontaneously to the sacroanterior position (the baby's back should be anterior to the mother). If the baby's back is not anterior to the mother, it may be necessary to gently rotate the baby to achieve this position. To rotate the baby, hold the baby's bu ocks over the iliac crests and gently rotate so the baby's back is towards the midline of the mother's abdomen. It is important not to squeeze the baby's abdomen or pull on the baby's legs. The paramedics should continue to observe the descent of the baby's bu ocks through the perineum. As the bu ocks continue to descend, the knees will pass through the introitus and the legs should spontaneously deliver. If the legs are extended, they may not deliver until the chest is born (Pairman et al., 2014). If progress is halted at this point, it may be necessary to assist delivery of the legs by using two ﬁngers to apply gentle ﬂexion at the popliteal fossa or behind the knee joint and two ﬁngers of the same hand over the baby's shin to bring the legs down, one at a time. Once the baby's legs are delivered, they should allow the baby to descend to its shoulders. At this stage it is possible to gently palpate the cord to check the fetal heart rate, but overhandling the cord can cause it to spasm (Pairman et al., 2014). Do not pull down on the cord (ALSO, 2004; Woollard et al., 2008). Usually the baby's shoulders will spontaneously deliver without any interference. If this does not occur, it may be because the arms are extended over the baby's head, thus stopping progress of the baby's head through the pelvis due to the added bulk of the arms. To enable the head to enter the pelvis, it will be necessary to assist by using Løvset's manoeuvre (see Fig 54.12). This involves a series of rotations and downward traction of the baby. Keeping the back uppermost, the paramedic rotates the baby's body as much as 180° so that the posterior shoulder is lying under the symphysis pubis, then sweeps the ﬁrst arm across in front of the baby's face (like a cat licking its face) and down beside the baby's chest. Then, keeping the baby's back uppermost, the paramedic rotates the baby back in the opposite direction at least 180° and using the same manoeuvre brings the second arm down and delivers the shoulders. FIGURE 54.12 Løvset's manoeuvre. Source: Pairman et al. (2014). Once the shoulders are visible the baby's head will enter the mother's pelvis and the baby must be born within 6 minutes (Pairman et al., 2014). While it is important to be cognisant of this timeframe, it is also necessary to avoid a rapid birth as sudden decompression can lead to intracranial haemorrhage. The paramedic should allow the baby to hang and be hands oﬀ. If the back starts to rotate oﬀ centre, the baby can be gently rotated back by encircling the pelvic girdle with two hands. Wrapping a warm towel around the baby's bo om can help avoid hypothermia. Once the nape of the baby's neck and hairline are visible, the mother should be encouraged to lean forwards at the waist to tilt her pelvis, aiding clearance of the baby's mouth and nose. Do not tug or pull the baby at any stage during this process. Sometimes it is necessary to provide assistance for the birth of the baby's head using the modiﬁed Maurice-Smellie-Viet manoeuvre (see Fig 54.13). To ensure favourable diameters, the head must be birthed by ﬂexion. One paramedic should apply suprapubic pressure to encourage ﬂexion of the occiput while the other second paramedic kneels in front of but lower than the woman. The second paramedic straddles the baby's body over one arm with the ring and index ﬁnger on the baby's cheeks (maxillae) and the middle ﬁnger on the baby's chin. The other hand is on the baby's back with the middle ﬁnger pushing down on the baby's head to keep it in the ﬂexed position, but some traction on the shoulders may be required with the other ﬁngers. The second paramedic slowly brings the head downwards keeping the body in a neutral position and brings the baby in a large arch to lie on the mother's stomach. FIGURE 54.13 Maurice-Smellie-Viet manoeuvre. Source: Pairman et al. (2014). If there is continued diﬃculty with the birth of the baby's head, the paramedics should place the mother in the McRobert's position (see Fig 54.14). One paramedic should apply suprapubic pressure to assist with ﬂexion of the baby's head. If the head still does not deliver, the mother should be maintained in this position and transported as quickly as possible to the nearest obstetric facility (Pairman et al., 2014; Woollard et al., 2008). FIGURE 54.14 McRobert's position. Source: Pairman et al. (2014). Once the baby has been born, the paramedics should manage the baby as per neonatal resuscitation and manage the third stage as per normal vaginal birth. When the baby and mother are stable, they should be transported to hospital. CASE STUDY 3 Case 13157, 0700 hrs. Dispatch details: A 38-year-old female, who is 42 weeks pregnant, is in labour. Initial presentation: The paramedics ﬁnd the patient semi-recumbent on the couch. She tried to get in the car but was unable to. ASSESS 0710 hrs History: The patient says her contractions commenced at 5 this morning. They have been unbearable for about an hour and she has been pushing for half an hour. She also says that her previous two children were large and she has been diagnosed with gestational diabetes during this pregnancy. 0715 hrs Examination: On examination the paramedics notice anal pouting and perineal bulging. As they prepare to assist with the birth her membranes spontaneously rupture and they observe that the amniotic ﬂuid has a greenish colour. With each contraction the patient pushes but the progress is slow, so the paramedics decide to transport her. However, as they prepare to transfer her to the stretcher, the baby's head becomes visible, so they decide to stay. The baby's head crowns after the patient pushes for ﬁve more contractions. The head is birthed but it fails to restitute. Shoulder dystocia The simplest deﬁnition of shoulder dystocia is when the baby's head is delivered but the progression of the shoulders into the maternal pelvis fails because the anterior shoulder, or occasionally the posterior shoulder, is impacted under the pubis symphysis. However, a more accurate deﬁnition is that when the usual downward traction of the head fails during normal vaginal birth, additional manoeuvres are required to assist the progression of the shoulders into the pelvis to facilitate the birth. An incidence rate of 0.6% for shoulder dystocia has been reported in North America and the UK (Alhadi et al., 2001). Around 48% of all cases occur in infants < 4000 g (Baske & Allen, 1995). There is an increased occurrence in women with a prolonged active ﬁrst stage and a prolonged second stage (Alhadi et al., 2001). Predisposing factors include: macrosomic baby (> 4000 g) maternal diabetes mellitus, including type 1, type 2 and gestational diabetes, leading to a large baby small maternal pelvis (e.g. platypelloid pelvis) increasing maternal age > 35 years old maternal BMI > 30 short maternal stature post-maturity previous history of shoulder dystocia prolonged active ﬁrst and second stages of labour. However, it is often unpredictable with no predisposing factors. Warning signs of shoulder dystocia In the out-of-hospital se ing early recognition of probable shoulder dystocia is the most eﬀective management. Given that shoulder dystocia has been shown to be associated with a prolonged second stage (Alhadi et al., 2001), if the woman is not progressing well in the second stage the paramedics should transport her to the nearest obstetric facility. If transport is not an immediate option (due to location or distance to hospital), shoulder dystocia presenting with an obstructed second stage may respond to a manoeuvre that changes the angle of the pelvis relative to the spine, creating a li le more room for the anterior shoulder to slip under the symphysis pubis at the front of the pelvis. There are a number of positions, all of them with esteemed individuals’ names, but they are all a combination of changing the angle of the pelvis and applying a li le downward traction to help the shoulder slip under the symphysis pubis. If these techniques do not work, the patient needs to be in expert hands as soon as possible. Recognition of shoulder dystocia Signs of shoulder dystocia as the head is birthing include: diﬃculty with progress of the head and chin the head burrows into the perineum ('turtle neck’ sign) restitution of the head does not occur, a sign that the shoulders have not entered the pelvis. Do not confuse 'bed’ dystocia or 'snug shoulders’ with 'mild’ dystocia (Pairman et al., 2014). 'Bed’ dystocia occurs when a woman lies in the semiFowler's or semi-recumbent position and the baby's head is born into the ma ress of the bed. The shoulders are not impacted behind the pubis symphysis. While progress of the head may be slow, the 'turtle neck’ sign does not occur. This is easily managed by changing the woman's position to all fours, standing or rolling to the left lateral (Pairman et al., 2014). TREAT As shoulder dystocia is often unexpected, paramedics should know the basic manoeuvres used to manage this obstetric emergency. It is advisable to request a second ambulance, especially as there is an increased likelihood of the baby requiring supportive measures after this type of delivery. Management requires at least two paramedics and may even need the assistance of any available bystanders to employ the following manoeuvres. Continue to use downward traction to deliver the baby's head but do not twist the head or use excessive force. As quickly as possible the mother should be placed in a semi-recumbent position on one pillow. Her knees should be pulled to her chest, slightly abducting, in the McRobert's manoeuvre (see Fig 54.14 and Box 54.2). If the mother is very tired she may need some assistance with this. A empt to birth the baby again by applying gentle downward traction to the baby. BOX 54.2 Limitations in the out-of-hospital setting In a hospital or home birth, procedures such as episiotomy and internal manoeuvres are used for shoulder dystocia. However, the value of an episiotomy in shoulder dystocia is often debated (Baston, 2006) and internal manoeuvres can be complicated. While paramedics are limited by the procedures they can perform in the out-of-hospital se ing, 58% (Gherman et al., 2006) to 90% (Carlin & Alﬁrevic, 2006) will be successfully managed by using the McRobert's, Rubin 1 or Gaskin manoeuvre. The McRobert's manoeuvre has beneﬁts for both the mother and the baby. This position rotates the sacrum backwards, straightening it relative to the lumbar vertebrae and allowing the pelvic inlets to open to the maximum diameter possible. This enables the symphysis pubis to rotate over the top of the anterior shoulder. Simultaneously the fetal spine straightens, facilitating the posterior shoulder passing over the sacral promontory into the hollow of the sacrum (Carlin & Alﬁrevic, 2006; Pairman et al., 2014; Rankin, 2017). In the Rubin 1 manoeuvre the second paramedic should a empt to identify the baby's back by checking which way the baby is trying to face. Remember, although restitution will not have occurred completely at this stage, the baby will be trying to turn one way rather than the other. Once the back is identiﬁed, the second paramedic should stand on that side of the mother. With both hands interlocked but using the heel of one hand (external compression style), the second paramedic with moderate pressure should push down and away on the anterior shoulder (Carlin & Alﬁrevic, 2006; Pairman et al., 2014; Rankin, 2017). In the Gaskin manoeuvre the woman is placed in the 'all fours’ position. In reality, this is an upside-down McRobert's manoeuvre. The ﬂexible sacroiliac joint opens, increasing the anteroposterior diameter by a further 1–2 cm and allowing suﬃcient room to deliver the posterior shoulder (Carlin & Alﬁrevic, 2006; Pairman et al., 2014; Rankin, 2017). If the McRobert's manoeuvre is unsuccessful, the mother should continue to remain in that position. The second paramedic should apply suprapubic pressure to the anterior shoulder and perform the Rubin 1 manoeuvre (see Box 54.2). Initial continuous pressure should be applied for 30 seconds but if this is not successful, the second paramedic should rock back and forth on the heel of the hand for a further 30 seconds. During this procedure the paramedic assisting should continue to apply gentle downward traction. If the above manoeuvres are unsuccessful, the mother should be placed on all fours or in the Gaskin position with her head as low as possible, her pelvis as high as possible and her hips well ﬂexed (see Box 54.2). Apply gentle downward traction to the posterior shoulder (i.e. nearest to the mother's back). If this is not successful, the mother should be placed in the ambulance and transported to the nearest obstetric facility. The receiving hospital should be notiﬁed of the problem and the impending arrival. En route apply oxygen to the mother and if able insert an intravenous therapy line. Do not stay on scene to do this as this is a true emergency. If the baby is born during any of this procedure the neonate should be managed as per the neonatal resuscitation guidelines (see Ch 55). The mother should be managed as per the third stage. She will be at greater risk of postpartum haemorrhage due to perineal trauma and an atonic uterus. CASE STUDY 4 Case 11834, 1420 hrs. Dispatch details: A 34-year-old woman, who is 35 weeks’ pregnant, in labour, membranes broken. Initial presentation: The ambulance crew ﬁnd the patient si ing in a chair in the manager's oﬃce of the local supermarket, in labour with her sixth child. ASSESS 1435 hrs History: The patient says was doing the weekly shopping when she felt a gush of clear ﬂuid from her vagina. She has been having slight pains all morning but they have become more frequent since her membranes ruptured. She says that she can feel something in her pants but has been too scared to look. 1438 hrs Examination: On inspection the paramedics see part of the umbilical cord hanging from her vagina. There are no signs of the second stage. Cord prolapse In cord presentation the baby's umbilical cord lies in front of the presenting part but the membranes have not ruptured. When the membranes have ruptured this becomes cord prolapse (see Fig 54.15). An occult cord prolapse lies adjacent to the presenting part and an overt cord prolapse lies below the presenting part. Cord prolapse may occur if a woman is not in labour, or is in the ﬁrst stage or third stage. As paramedics do not have the equipment to monitor the fetal heart it is not possible for them to diagnose and therefore manage either a cord presentation or an occult cord prolapse. The incidence of cord prolapse is around 0.2–0.4% of all births (Carlin & Alﬁrevic, 2006). Predisposing factors include: FIGURE 54.15 In cord presentation the baby's umbilical cord lies in front of the presenting part and the membranes have not ruptured. When the membranes rupture this becomes cord prolapse. Source: Pairman et al. (2014); Henderson & Macdonald (2004). a high presenting part multigravida malpresentation (e.g. breech, shoulder, face or brow; transverse or oblique lie) prematurity or birth weight < 2.5 kg multiple birth (e.g. twins, triplets) excessive amniotic ﬂuid (polyhydramnios) mother of Afro-Caribbean descent with high assimilation pelvis after external cephalic version (for breech). TREAT Without the equipment to diagnose an occult cord prolapse, paramedics can only manage the condition when they visualise the cord external to the vagina. It is generally outside the scope of practice for paramedics to perform a vaginal examination and the mother could still be in the ﬁrst stage of labour. Even if they suspect that the mother is in the second stage of labour, the paramedics should deliver the baby only if the presenting part is in view, as the second stage can take as up to an hour or more to complete. If the presenting part is in view, the birth of the baby is the fastest way to remove the cord compression. The aim of managing an overt prolapse is to prevent or minimise cord compression by the presenting part by elevating the pelvis as high as possible. Because cord compression eﬀectively cuts oﬀ the oxygen supply to the fetus the key is to take the pressure oﬀ the presenting part as it engages with the pelvis. This will cause transport diﬃculties, as it is hard to maintain a high pelvis position in a moving environment. Direct communication with the receiving facility will not only allow them preparation time but will also provide the paramedics with advice, particularly with reference to manual disimpaction of the presenting part from the pelvis. If the mother is not in labour Place her in the 'all fours’ position, knees to chest, with the pelvis as high as possible in the air (Curran, 2003; Pairman et al., 2014; Rankin, 2017; Woollard et al., 2008). While there is li le evidence supporting the eﬀectiveness of oxygen to assist fetal distress, providing supplemental oxygen to the mother remains a common and acceptable practice (Curran, 2003; Rankin, 2017). If the cord is external to the vagina it may be in danger of cooling and drying out. However, overhandling the cord can cause spasming and vasoconstriction. Paramedics need to be aware of these dangers but it may be necessary to gently place the cord in the vagina to prevent it drying out (Woollard et al., 2008). If the cord continually falls out, it may be necessary to cover it with saline-soaked gauze. One paramedic should insert a hand into the woman's vagina and manually push the presenting part oﬀ the cord with at least two ﬁngers. This can be very diﬃcult, particularly if the presenting part is very high (Curran, 2003; Pairman et al., 2014; Rankin, 2017; Woollard et al., 2008). Transport as quickly as possible to the nearest obstetric facility. The safest position during transport is the exaggerated Sims or left lateral position. The woman's pelvis must remain higher than her shoulders to keep the presenting part oﬀ the cord. If the mother is in labour Perform all of the above. Provide the mother with pain relief—usually inhaled, unless contraindicated. Encourage the mother to pant during contractions and avoid pushing down unless the presenting part is in view. If the presenting part is in view Prepare to assist with the birth of the baby. Coach the mother to push hard when she has a contraction. Prepare neonatal resuscitation equipment (see Ch 55). CASE STUDY 5 Case 11268, 0345 hrs. Dispatch details: A 29-year-old woman who is 38 weeks’ pregnant is in labour and pushing. Initial assessment: The ambulance crew ﬁnd the patient in the bathroom lying against the wall, with her baby, still a ached to the umbilical cord, in her arms. ASSESS 0358 hrs History: The baby was born 10 minutes ago. 0406 hrs Examination: Following a vital signs survey, the paramedics transfer the patient to the bedroom. They note some blood loss on the ﬂoor. The bleeding continues substantially after delivery of the placenta, so they check her uterus and notice that it is boggy (not contracted). Postpartum haemorrhage A postpartum haemorrhage (PPH) can be deﬁned as blood loss of greater than 500 mL from the time of the birth of the baby, including the third stage, until 24 hours later. A very severe primary PPH involves a blood loss greater than 1000 mL. However, sometimes blood loss is diﬃcult to quantify during birth as it is often mixed with amniotic ﬂuid. PPH can also be deﬁned as any amount of postpartum bleeding that causes haemodynamic compromise (Coad & Dunstall, 2011; Royal College of Obstetricians and Gynaecologists, 2011; Rankin, 2017; Woollard et al., 2008). The incidence of primary PPH ranges from 5% to 15% of all births (Rankin, 2017). PPH has been reported in Australia at a rate of 6.2–6.5% of all BBAs (Flanagan et al., 2017; McLelland et al., 2018). It was the leading cause of maternal death in the UK between 2003 and 2005 (Royal College of Obstetricians and Gynaecologists, 2011). Two-thirds of women who have a primary PPH have no identiﬁable risk factors (Pairman et al., 2014). For causes of PPH, think of the '4 Ts’. Tone: causes 90% of PPH (Pairman et al., 2014) > Atonic uterus includes precipitate births, prolonged labour, multiple birth, grand parity, prolonged third stage Trauma > Perineal tears includes precipitous birth, malposition Tissue > Retained products includes either whole or partial placenta or membranes Thrombin: causes < 1% of PPH (ALSO, 2004) > Clo ing disorders due to pre-eclampsia or haemolysis elevated liver enzymes low platelets (HELLP) syndrome, pyrexia, deep vein thrombosis (DVT) Signs of primary PPH Visible blood loss is often the ﬁrst sign, so any visible loss must be assessed. Due to changes in the cardiovascular system at term (Coad & Dunstall, 2011; Dundas, 2003; Rankin, 2017) early signs of shock can be masked until the woman has lost up to one-third of her blood volume (Pairman et al., 2014) and is very compromised, so paramedics should be alerted to: an increase in heart rate by 20 bpm any decrease in blood pressure any signs of pallor. Although unlikely, if clots are retained in an atonic uterus the ﬁrst signs of a primary PPH would be: cold, clammy and pale skin an enlarged and boggy uterus altered conscious state (Rankin, 2017). TREAT Although postpartum haemorrhage can be very dramatic and is deﬁnitely lifethreatening, a massive haemorrhage is much nearer to the paramedic's usual emergency management than emergencies associated with delivery. Lifethreatening postpartum haemorrhage is thankfully relatively rare in paramedic practice so it is recommended that paramedics consult with the receiving facility for advice and support as they a empt to control the haemorrhage with compression. Paramedic management The aim of paramedic management is to recognise bleeding early and to stop or minimise blood loss to prevent a severe postpartum haemorrhage (> 1000 mL). Specific management Paramedics should request support from a second crew to allow them to concentrate on the mother's condition while ensuring that the baby is supported. If the placenta has not yet delivered Any vaginal bleeding after birth indicates the placenta has separated. Ask the mother to push the placenta out. If unable to cut the cord, use controlled traction to deliver the placenta (see Box 54.3). This is not usually recommended in the out-of-hospital se ing but in an emergency may be necessary (Woollard et al., 2008). Check the uterine fundus for a contracted uterus. An empty contracted uterus does not bleed. If the uterus has contracted: > Do not ‘ﬁddle’ with it as it may cause it to relax. Do not ‘rub up’ or massage it. > Check for any visible laceration and apply direct pressure (Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017). > Manage as below. If the placenta has delivered but the uterus has not contracted Using a circular motion with a cupped hand massage or rub up the uterine fundus until it is ﬁrm. Warn the woman ﬁrst, as this is painful (Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017). Manage as below. Postpartum haemorrhage management After delivery of the placenta and contraction of the uterus, the following management is required. Have the woman lie down. Her legs can be elevated on a pillow (Fraser & Cooper, 2009) but her pelvis should not be tilted. Commence oxygen at 8 L/min via mask (Mathai et al., 2007; Pairman et al., 2014; Woollard et al., 2008). Insert two large-bore (16 gauge or as wide as available) intravenous cannula and commence 1–2 litres of crystalloid solution (e.g. Hartmann's, normal saline) (World Health Organization, 2017; Pairman et al., 2014; Woollard et al., 2008). While crystalloid ﬂuids may prove successful in restoring volume in mild or moderate PPH, consideration must be given to haemodilution and coagulopathy if large volumes of ﬂuids are administered (Schorn & Phillippi, 2014). Give oxytocic drugs if available (e.g. IM Syntocinon 10 IU/s; Misoprostol 800 microgram oral/rectal). Ask the woman to empty her bladder if she is able to (Fraser & Cooper, 2009; Pairman et al., 2014; Rankin, 2017; Woollard et al., 2008). Encourage the baby to breastfeed if possible. Notify the receiving hospital and transport as quickly as possible. If available, consider administration of tranexamic acid (TXA) 1 g IV. While still relatively uncommon in the out-of-hospital se ing, TXA has been shown to reduce mortality in women suﬀering a PPH (WOMAN Trial Collaborators, 2017). Other manoeuvres that can be used if bleeding continues are bimanual compression and aortic compression. The use of these is governed by local guidelines and procedures and should be undertaken only as a last resort by paramedics in the ﬁeld. Procedure for delivering the placenta Guard the uterus with one hand to prevent inversion by placing the hand over the symphysis pubis and applying gentle pressure downwards and backwards. Do not move this hand until the placenta is visible in the introitus. Apply gentle downwards traction on the cord with the other hand until the placenta is visible at the opening of the vagina. Do not pull or tug. If the cord does not descend, stop traction and wait for the cord to descend. Once the placenta can be seen at the introitus, grasp the cord where it joins the placenta. Remove the hand on the symphysis pubis and use this hand to hold the emerging placenta. With a twisting motion aid complete delivery of the placenta and membranes. The twisting action assists in removing as much of the membranes as possible. Massage the fundus until it is ﬁrmly contracted. If the uterus is not contracting and bleeding still continues after fundal massage and the administration of oxytocic drugs, more invasive measures may be required. Bimanual compression is preferred in the hospital se ing as it is eﬀectively direct pressure on the placental site. However, in the pre-hospital se ing without long gloves this may put paramedics at risk of blood-borne diseases. Aortic compression, which temporarily stops the ﬂow to the uterus and thus prevents bleeding, is often preferred. Both methods are very painful, so if the woman does not have an altered conscious state, she should be oﬀered pain relief. For bimanual compression: Wear long, preferably sterile gloves. Insert one hand into the vagina and remove any obvious clots. Form a ﬁst and place it in the anterior fornix of the vagina, applying pressure against the anterior wall of the uterus. Using the other hand, apply pressure deep in the abdomen behind the uterus on the posterior wall (see Fig 54.16). FIGURE 54.16 Bimanual compression. Source: Pairman et al. (2014). For aortic compression: Form a ﬁst and push it into the woman's abdomen slightly above the umbilicus and to the left. Push ﬁrmly through the abdominal wall, causing compression of the aorta supplying the uterus. The pulsation of the aorta is easy to feel through the abdominal wall. Eﬀectiveness can be assessed by checking cessation of the femoral pulse. If the femoral pulse cannot be felt, compressions are adequate. If the pulse is felt, compressions are inadequate. Check extremities for anoxia. Both methods are only temporary and immediate transport to the nearest maternity service is required. Further research Research continues to look at how Australian paramedics respond to and manage out-of-hospital obstetric emergencies. Further research is required to validate in the out-of-hospital se ing recent advances in obstetric and midwifery care such as the ﬁndings of the WOMAN trial into tranexamic acid use for postpartum haemorrhage (WOMAN Trial Collaborators, 2017). A Delphi study of ambulance managers revealed that obstetrics is one of the few clinical areas where paramedics want further continuing education (Snooks et al., 2009). In the United Kingdom, a Prehospital Obstetric Emergency Training (POETs) course is now available for qualiﬁed paramedics (Woollard et al., 2008). The course is held over 2 days and focuses on training paramedics to manage obstetric emergencies. An improvement in the outcomes of out-of-hospital deliveries would suggest that specialised training would be useful in other areas. Summary Most out-of-hospital births are full term and uncomplicated. Although minimal intervention will be required, paramedics still need a basic understanding of the physiology of labour to enable clinical decision-making. Obtaining a thorough obstetric and medical history will enable them to make appropriate clinical decisions regarding out-of-hospital management of the patient. Paramedics will rarely encounter obstetric complications but they do need an understanding of the basic manoeuvres in order to manage them. It is important to be able to recognise the diﬀerence between the ﬁrst and the second stage of labour: when to ‘stay’ or ‘go’. Since labour is dynamic, paramedics need to continually monitor for any changes in the woman's condition to determine the need to stop en route to hospital. The third stage of labour is often the most vulnerable time for the woman. Physiological management of the third stage is the recommended procedure in the out-of-hospital se ing and paramedics should try to avoid cu ing the umbilical cord as it commits them to active management. Paramedics should be aware that by the time the woman displays signs of deterioration or shock during labour, she and the baby are already haemodynamically compromised. Unless there is a medical reason for separation, mother and baby should remain together, skin-to-skin, during transport.

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