01Approach to the Critical Patient/attcp97

Recognition and first response

›Shoulder dystocia is a bony impaction that traction alone will not relieve

›Anterior fetal shoulder is trapped behind the maternal pubic symphysis after the head delivers

›Less often the posterior shoulder is impacted on the sacral promontory

›The diagnosis is clinical, made by the delivering clinician, and needs no imaging

›Declare the emergency the moment gentle axial traction fails to deliver the shoulders

›Say the words shoulder dystocia so the whole team moves to the drill

›Announce and record the time the head delivered

›Nominate a scribe for maneuvers, times, and personnel

›Nominate a timekeeper to call elapsed time every 30 seconds

›Summon help immediately

›Most senior obstetrician or clinician available

›At least two extra staff for the maternal legs

›Neonatal or paediatric team for a potentially depressed infant

›Anaesthesia in case cephalic replacement or theatre is needed

›Prepare the patient and space

›Lay the bed flat and bring the buttocks to the edge

›Drain the bladder only if it is quick and easy

›Ask the mother to stop pushing until a maneuver requires it

›Prepare for neonatal resuscitation in parallel

›Radiant warmer, suction, and a correctly sized bag-mask

›Cord clamps and a syringe set for paired cord gases

›Call the resuscitation team to the bedside before delivery of the body

HELPERR sequence and escalation

›Help, and initial preparation

›Senior obstetric, neonatal, and anaesthetic staff, plus scribe and timekeeper

›Patient flat, buttocks to the edge of the bed, pushing paused

›Evaluate for episiotomy

›Episiotomy does not relieve the bony block and does not by itself prevent brachial plexus injury

›Cut a mediolateral or midline episiotomy only to admit a hand for internal maneuvers

›Legs, the McRoberts maneuver, used first

›Hyperflex both hips so the thighs meet the abdomen, then abduct and externally rotate

›Rotates the symphysis cephalad and flattens the sacral promontory without changing true pelvic dimensions

›Resolves roughly 40% of cases when used alone

›Pressure, suprapubic

›Press just above the symphysis, downward and toward the side the fetal face points, over the anterior shoulder

›Aim to adduct the shoulder girdle and move the shoulder into the oblique diameter

›Thirty seconds of continuous pressure, then a rocking motion if unsuccessful

›Never apply fundal pressure

›Enter, internal rotational maneuvers

›Rubin II, pressure on the posterior aspect of the anterior shoulder to adduct it

›Woods corkscrew, add pressure on the anterior aspect of the posterior shoulder and rotate 180 degrees

›Reverse Woods, rotate the opposite way if the first attempt fails

›Remove the posterior arm

›Follow the posterior humerus to the elbow, flex it, and sweep the forearm across the chest and out

›Delivers the highest proportion of cases that survive first-line maneuvers

›Accept a possible humeral fracture as the price of delivery

›Roll to all fours, the Gaskin maneuver

›Move the mother onto hands and knees

›Enlarges the functional pelvic outlet and lets gravity assist

›A good choice for a lone provider and as a reset

›Escalate after roughly 4 to 5 minutes of a failing sequence

›Deliberate cleidotomy by a senior operator if the clavicle can be reached

›Zavanelli cephalic replacement then immediate caesarean

›Symphysiotomy only without caesarean access and with a trained operator

›Posterior axillary sling traction when the posterior arm cannot be reached

Interventions that worsen shoulder dystocia

›Forceful downward or lateral traction on the fetal head

›The instinctive response, and the dominant cause of permanent brachial plexus injury

›Use only gentle traction in line with the fetal spine, and only during a maneuver

›A fetus with an abnormal pre-delivery tracing or growth restriction has less reserve and is harmed sooner by any delay

›Fundal pressure

›Drives the shoulder harder onto the symphysis and raises uterine rupture risk

›It is not a substitute for correctly placed suprapubic pressure

›Cutting a nuchal cord before the body is delivered

›If the body then takes minutes, the only oxygen source has been severed

›Use the somersault maneuver or deliver through a loose loop instead

›Other harmful reflexes

›Continued maternal pushing during internal maneuvers

›Excessive lateral flexion or rotation of the fetal neck

›Maternal lithotomy for McRoberts beyond about 15 minutes, which risks femoral and lateral femoral cutaneous neuropathy

Iatrogenic harms from routine interventions

›Traction and time

›Forceful traction, the standard response to a slow shoulder, causes permanent brachial plexus avulsion

›Repeated traction wastes time and drives hypoxic-ischaemic injury

›Only gentle axial traction within a defined maneuver is acceptable

›Fundal pressure

›Causes uterine rupture and deepens the impaction

›Never appropriate in shoulder dystocia

›Airway management

›Neonatal intubation is for failed bag-mask ventilation or encephalopathy and must not delay effective ventilation or compressions

›Maternal intubation is only for general anaesthesia when theatre is required

›Sedation

›Maternal sedation removes the cooperation needed to stop pushing and to position

›Benzodiazepines cross the placenta and cause neonatal respiratory depression and hypotonia

›Fluid loading

›Appropriate for maternal haemorrhage, but excess crystalloid causes dilutional coagulopathy

›In the neonate give volume only for documented hypovolaemia, and slowly if preterm

›Oxygen

›Maternal oxygen has weak supporting evidence in this setting

›Hyperoxia harms the term neonate, resuscitate in air and titrate to saturation targets

›Vasopressors and circulatory support

›No primary role, maternal phenylephrine or ephedrine is only for neuraxial hypotension

›Neonatal circulatory support is epinephrine per the resuscitation algorithm

›Mechanical circulatory support including the intra-aortic balloon pump has no role for either patient

›Anticoagulation and fibrinolysis

›Withhold anticoagulation acutely and defer venous thromboembolism prophylaxis until bleeding has stopped, usually 6 to 12 hours after delivery

›Fibrinolysis is absolutely contraindicated peripartum because of catastrophic haemorrhage risk

›Analgesia

›Avoid systemic opioids in the second stage because of neonatal respiratory depression

›Withhold non-steroidal anti-inflammatory drugs until haemorrhage is controlled and renal perfusion restored

02History/hx42

Antenatal risk factors

›Strongest predictors from the obstetric history

›Prior shoulder dystocia, the single strongest predictor, with recurrence of approximately 10%

›Previous macrosomic infant regardless of whether dystocia occurred

›Pregestational or gestational diabetes in this pregnancy

›Fetal size indicators

›Estimated fetal weight above 4000 g, with risk rising steeply above 4500 g

›Large-for-dates fundal height or a clinically large fetus

›Polyhydramnios on a recent scan

›Maternal factors

›Obesity and excessive gestational weight gain

›Short stature or a known contracted or platypelloid pelvis

›Advanced maternal age and grand multiparity

›Pregnancy timing and control

›Post-term pregnancy beyond 41 weeks

›Poorly controlled maternal glucose in the third trimester

›The limits of prediction

›About half of cases occur with no risk factor at all

›Absence of risk factors does not permit reassurance or change delivery-room readiness

Intrapartum course

›Labour progression

›Prolonged first stage

›Prolonged or arrested second stage

›Precipitous second stage that outpaces trunk rotation

›Interventions during labour

›Induction or augmentation with oxytocin

›Operative vaginal delivery, forceps or vacuum, especially mid-cavity

›Epidural analgesia reducing expulsive effort and pelvic floor tone

03Physical Exam/exam44

Confirming the diagnosis

›Signs at the perineum

›Turtle sign, the head retracts tightly against the perineum

›Failure of spontaneous restitution of the head

›Difficulty delivering the chin over the perineum with bulging cheeks

›Failure to deliver

›Shoulders do not deliver with gentle axial traction and the next contraction

›Head-to-body interval exceeding 60 seconds with no progress

›Localising the impaction

›Anterior shoulder palpable above the symphysis on suprapubic palpation

›Vaginal examination for the position of the posterior shoulder and access to the posterior arm

›Assessment for bilateral impaction when neither shoulder is palpable in the pelvis

Maternal assessment

›Haemorrhage surveillance

›Measured blood loss from the moment of delivery, not an estimate

›Uterine tone after delivery of the placenta, a boggy uterus signalling atony

›Heart rate above 110 per minute or systolic below 90 mmHg suggesting significant haemorrhage

›In chronic hypertension a normal-looking pressure can still represent hypoperfusion

›Genital tract trauma

›Systematic inspection of perineum, vagina, and cervix

›Grading of any obstetric anal sphincter injury, third or fourth degree

›Anterior vaginal wall and periurethral inspection for tears from internal maneuvers

›Musculoskeletal and neurological injury

›Symphyseal tenderness, a palpable gap, or difficulty weight-bearing

›Lower limb power and sensation after prolonged hyperflexion, screening for femoral neuropathy

›Bladder

›Distension or inability to void suggesting bladder atony or urethral injury

›Bladder scan to confirm emptying

04Differential Diagnosis/ddx24

Mechanical causes of impacted shoulders

›True shoulder dystocia

›Anterior shoulder behind the symphysis, the common and immediately dangerous cause

›Posterior shoulder impacted on the sacral promontory, the same danger, often relieved by all-fours or posterior arm delivery

›Bilateral impaction

›Both shoulders above the pelvic inlet, rare and severe

›Often needs cephalic replacement and caesarean

›Maternal bony and soft-tissue obstruction

›Contracted or platypelloid pelvis narrowing the outlet

›Bandl pathological retraction ring trapping the trunk

›Pelvic mass such as a low fibroid or ovarian cyst

Mimics and pseudo-dystocia

›Cord and effort problems that are not true dystocia

›Short or nuchal umbilical cord tethering the fetus, dangerous only if the cord is cut

›Inadequate maternal expulsive effort or exhaustion, common and low risk, never treated with added traction

›Fetal structural anomaly enlarging the neck or trunk

›Fetal goitre or cystic hygroma

›Fetal ascites or hydrops

›Sacrococcygeal teratoma or an abdominal tumour

›Marked hepatosplenomegaly or an abdominal wall mass

›Twin-related obstruction

›Locked twins when the second twin obstructs the first

›Conjoined twins presenting as an undeliverable trunk

›Congenital contracture

›Fetal arthrogryposis fixing the shoulder girdle

›Skeletal dysplasia with a broad thorax

05Laboratory Tests/lt36

Umbilical cord blood gas

›Sampling technique

›Paired arterial and venous samples immediately after delivery for every shoulder dystocia

›Double-clamp a cord segment, samples stay valid for about 60 minutes if the segment remains clamped

›An unclamped segment becomes progressively more acidotic and falsely worsens the result

›Thresholds

›Arterial pH below 7.0 with a base deficit of 12 mmol/l or more defines significant metabolic acidaemia

›Preterm birth, maternal acidaemia from diabetic ketoacidosis or sepsis, and chronic placental insufficiency shift the baseline and must be read in context

›Use the base deficit in the extracellular fluid compartment when applying the 12 mmol/l threshold

›Verifying separate vessels

›An arterial-venous pCO2 difference above about 8 mmHg and a pH difference of at least 0.02 confirm two different vessels

›Two near-identical results usually mean both samples are venous and understate fetal acidaemia

›Adjuncts and traps

›Cord lactate tracks pH, a high lactate with a near-normal pH points to a sampling or timing error

›A high nucleated red cell count suggests a subacute rather than acute insult and redirects the timing of injury

Maternal laboratory studies

›Haemorrhage workup

›Complete blood count for a baseline and haemorrhage assessment

›Group and screen on every case, crossmatch two units if bleeding continues

›Fibrinogen, prothrombin time, and activated partial thromboplastin time if loss exceeds 1000 ml or bleeding continues

›Fibrinogen below 2 g/l predicts progression and guides cryoprecipitate

›Perfusion markers

›Venous lactate and base deficit in suspected haemorrhagic shock

›Serial haemoglobin to track ongoing loss

›Metabolic and immunological

›Random glucose and later HbA1c if diabetes was never formally tested

›Kleihauer-Betke test in a rhesus-negative mother to size the fetomaternal haemorrhage and the anti-D dose

06Diagnostic Tests/dt41

Scoring Systems

›Prediction has no validated tool

›Shoulder dystocia has no validated antenatal predictive score

›Macrosomia prediction models perform poorly and should not be used alone to plan delivery

›Estimated fetal weight by ultrasound carries an error of roughly 15%

›Neonatal scoring

›Apgar score at 1, 5, and 10 minutes

›Sarnat staging to grade encephalopathy as mild, moderate, or severe and to set cooling eligibility

›Modified Sarnat or Thompson score for serial encephalopathy assessment

›Process measures

›A structured shoulder dystocia documentation proforma recording maneuvers, times, and personnel is the medico-legal standard

›Time from head to body delivery recorded as the key process metric

MRI

›Neonatal brain MRI on day 2 to 4 for suspected hypoxic-ischaemic encephalopathy

›An acute profound insult targets the basal ganglia, thalami, and posterior limb of the internal capsule

›A prolonged partial insult produces a watershed cortical and white matter pattern

›Diffusion-weighted imaging can pseudonormalise around day 7 to 10, so timing matters

›Brachial plexus MR neurography at 3 to 6 months if there is no recovery

›Distinguishes root avulsion from a postganglionic rupture

›Guides the timing of microsurgical exploration

›Maternal pelvic MRI

›Rarely needed, reserved for suspected symphyseal or sacral injury with persistent pain or instability

›Preferred over CT for maternal pelvic soft tissue and for the neonatal brain because it uses no ionising radiation

CT

›No acute diagnostic role

›CT does not diagnose shoulder dystocia itself

›Neonatal head CT only when MRI is unavailable and intracranial haemorrhage must be excluded urgently, accepting the radiation

›Maternal indications

07Disposition/dispo34

Maternal disposition

›Admission and monitoring

›Every mother is admitted to an obstetric or high-dependency bed for at least 24 hours

›Active third-stage management with uterine tone and blood loss checked every 15 minutes initially

›Formal repair of any third or fourth degree tear in theatre by a skilled operator

›Recovery support

›Analgesia, laxatives, and physiotherapy for perineal or pelvic girdle injury

›Venous thromboembolism prophylaxis once bleeding has stopped

›Communication and planning

›Structured debrief with the mother and birth partner, with written documentation of events

›Referral for birth-trauma or perinatal mental health follow-up

›Counselling that a future pregnancy carries recurrence of approximately 10% and needs early obstetric planning

Neonatal disposition

›Well infant

›Vigorous infant, normal cord gases, and a normal limb and clavicle examination after a McRoberts-only delivery goes to routine postnatal care

›Document a repeat examination before discharge

›Infant needing admission

›Any resuscitation beyond stimulation, an abnormal cord gas, or an abnormal neurological examination prompts neonatal unit admission

›Infant of a diabetic mother needs a glucose protocol and feeding support before discharge

›Encephalopathy pathway

›Start passive cooling and refer to a therapeutic hypothermia centre

›Gestation 36 weeks or more and within 6 hours of birth

›Cord or first-hour pH below 7.0 or base deficit of 12 mmol/l or more, or a 10-minute Apgar of 5 or less, or ongoing resuscitation at 10 minutes

›Plus moderate or severe encephalopathy on examination or amplitude-integrated EEG

›Injury follow-up

›Brachial plexus palsy, refer to a specialist clinic within 2 to 4 weeks and start gentle range-of-motion physiotherapy

›Isolated clavicle fracture, analgesia and careful handling, outpatient newborn review

08Treatment/t116

First-line maneuvers

›McRoberts maneuver

›Hyperflex both hips onto the abdomen, then abduct and externally rotate, one assistant per leg

›Hold about 30 seconds while gentle axial traction is applied with a contraction

›Rotates the symphysis over the shoulder without enlarging the true pelvis

›Return the legs to neutral between attempts and keep total lithotomy time under about 15 minutes

›Suprapubic pressure

›Find the anterior shoulder just above the symphysis and press downward and toward the fetal face

›Thirty seconds of continuous pressure, then a rocking motion if the shoulder has not disimpacted

›Combine with McRoberts, which together resolve a large majority of cases

›Never convert this to fundal pressure

›Episiotomy for access

›Its purpose is room for a hand, not relief of the bony block

›Infiltrate with lidocaine 1% up to 4.5 mg/kg or 300 mg plain before cutting if there is no working regional block

›Coordinate maternal effort

›Pause pushing until an internal maneuver calls for it

›Resume gentle pushing only on the operator's cue

Rotational and posterior arm maneuvers

›Deliver the posterior arm

›Pass a hand along the fetal back to the posterior humerus, flex the elbow, and sweep the forearm across the chest and out

›Generally the most effective single maneuver

›Expect and accept a possible humeral shaft fracture, which heals well

›If the arm is extended behind the back, use posterior axillary sling traction with a soft catheter looped through the axilla

›Internal rotation

›Rubin II, pressure on the posterior aspect of the anterior shoulder to adduct it into the oblique

›Woods corkscrew, simultaneous pressure on the anterior aspect of the posterior shoulder to rotate 180 degrees

›Reverse Woods corkscrew if the first direction fails

›Rotate the shoulders, never the head or neck

›All-fours, the Gaskin maneuver

›Roll the mother onto hands and knees and apply gentle downward traction on the now-posterior shoulder

›Useful as a primary maneuver for a lone provider and as a reset when supine maneuvers fail

›Sequencing rule

›Change maneuver every 30 seconds without progress

›Do not repeat the same failed maneuver

Last-resort maneuvers

›Deliberate cleidotomy

›A senior operator fractures one or both clavicles by direct pressure toward the fetal chest to reduce the bisacromial diameter

›Accept clavicular fracture and possible vascular or pulmonary injury as the cost of delivery

›Zavanelli maneuver

›Reverse restitution to occiput-anterior, flex the head, and push it steadily back into the vagina

›Proceed immediately to caesarean with the head held up

›Give a uterine relaxant to allow replacement

›Symphysiotomy

›Surgical division of the symphyseal cartilage under local anaesthesia with the urethra displaced laterally by a finger

›Reserve for settings without caesarean access, morbidity includes urethral injury, fistula, and long-term pelvic instability

›Abdominal rescue

›Laparotomy and low transverse hysterotomy to rotate or disimpact the shoulder transabdominally when all else fails

Uterine relaxation for cephalic replacement

›Nitroglycerin, first choice for its very short duration

›50 micrograms IV, repeated in 50 to 100 microgram increments every 1 to 2 minutes to effect, or 400 micrograms as a sublingual spray

›Onset within about 1 minute, duration only a few minutes

›Stop escalating once the uterus relaxes or systolic pressure falls below 100 mmHg

›Cumulative ceiling in this setting about 400 micrograms IV before switching agents

›Monitor blood pressure every 1 to 2 minutes with a vasopressor and fluid ready

›Terbutaline, if nitroglycerin fails or is unavailable

›250 micrograms subcutaneous as a single dose

›Expect maternal tachycardia and tremor, with an effect far longer than nitroglycerin

›Avoid in significant maternal cardiac disease, uncontrolled hyperthyroidism, or severe pre-eclampsia

›Do not repeat within this event

›The beta-agonist drives potassium intracellularly, check potassium and watch the ECG for a long QT and U waves

›Anticipate the predictable consequence

›Both agents cause uterine atony by design

›Have oxytocin drawn up and plan haemorrhage management before giving them

Third stage and postpartum hemorrhage

›Oxytocin

›10 units IM with delivery of the anterior shoulder or immediately after birth for active management

›Or 5 units by slow IV injection over 1 to 2 minutes, never a rapid bolus, which causes hypotension and reflex tachycardia

›For ongoing bleeding infuse 40 units in 500 ml isotonic crystalloid over 4 hours

›Titrate the infusion to uterine tone, with no benefit above 40 units for this indication

›Recheck fundal tone and measured blood loss every 5 to 15 minutes during the infusion

›Tranexamic acid

›1 g IV over 10 minutes as soon as postpartum haemorrhage is recognised, ideally within 3 hours of birth

›Repeat 1 g once after 30 minutes if bleeding continues

›Second-line uterotonics for a persistently atonic uterus

›Carboprost 250 micrograms IM, repeat every 15 to 90 minutes, maximum 8 doses or 2 mg total

›Contraindicated in asthma and active cardiac, hepatic, or renal disease

›Ergometrine 500 micrograms IM or methylergometrine 200 micrograms IM

›Contraindicated in hypertension, pre-eclampsia, and coronary disease

›Misoprostol 800 micrograms sublingual or rectal when injectable agents are unavailable

›Mechanical and surgical measures in parallel

›Bimanual uterine compression and a bladder catheter

›Intrauterine balloon tamponade if drugs fail

›Escalation to examination under anaesthesia, compression sutures, or interventional radiology

›Blood products and adjuncts

›Transfuse to keep fibrinogen above 2 g/l and correct ionised calcium

›Anti-D 500 IU to a rhesus-negative mother, adjusted for the Kleihauer result

Perineal repair and maternal analgesia

›Timing of repair

›Repair episiotomy and lacerations once uterine haemostasis is secure and the infant is handed over

›Refer a third or fourth degree tear for repair in theatre

›Local anaesthetic

›Lidocaine 1% infiltration, maximum 4.5 mg/kg or 300 mg plain, or 7 mg/kg or 500 mg with adrenaline

›Top up an existing epidural rather than exceed the local anaesthetic ceiling

›Systemic analgesia after delivery

›Paracetamol 1 g orally or IV every 6 hours, maximum 4 g in 24 hours

›Ibuprofen 400 mg orally every 8 hours with food, maximum 1200 mg in 24 hours, only once haemorrhage is controlled and renal perfusion is adequate

›Reserve oral opioids such as oxycodone for breakthrough pain, avoid codeine in breastfeeding because of variable metabolism

›Avoid systemic opioids in the second stage before delivery because of neonatal respiratory depression

›Non-drug measures

›Ice packs for 10 to 20 minutes at a time for the first 48 hours

›Early mobilisation and a supportive dressing for perineal oedema

Neonatal resuscitation

›Follow the Neonatal Resuscitation Program sequence

›Most infants respond to drying, stimulation, and positive-pressure ventilation

›Ventilate a term infant in air at 21% oxygen and titrate to preductal saturation targets

›Approximately 60 to 65% at 1 minute, 80 to 85% at 5 minutes, and 85 to 95% at 10 minutes

›Preterm infants use lower early targets

›Do not chase 95% in suspected cyanotic congenital heart disease, and in persistent pulmonary hypertension or congenital diaphragmatic hernia keep preductal saturation above about 90% and avoid large swings

›Start chest compressions at a 3 to 1 ratio with ventilation if the heart rate stays below 60 per minute despite 30 seconds of effective ventilation

›Epinephrine

›0.02 mg/kg IV or intraosseous, range 0.01 to 0.03 mg/kg, using the 0.1 mg/ml concentration, repeat every 3 to 5 minutes

›Endotracheal dosing 0.05 to 0.1 mg/kg only while access is obtained

›Verify against current pediatric guideline before use

›Dextrose

›10% dextrose 2 ml/kg IV for glucose below 2.6 mmol/l, then an infusion at 5 to 8 mg/kg per minute

›Verify against current pediatric guideline before use

›Volume expansion

›Isotonic saline or O-negative blood 10 ml/kg IV over 5 to 10 minutes for hypovolaemia from blood loss, repeat once as needed

›Give slowly in the preterm infant to reduce intraventricular haemorrhage risk

›Verify against current pediatric guideline before use

›Injury care during resuscitation

›Support a flail arm and gently immobilise a suspected fractured humerus or clavicle

›If encephalopathy is evident, stop active warming, allow passive cooling toward 33 to 34 degrees Celsius, and arrange transfer, expecting a cooling-related heart rate of 80 to 100 per minute

09Special Populations/sp63

Pregnancy

›Every consideration here is a pregnancy consideration because shoulder dystocia is by definition intrapartum

›Risk stratification and delivery planning begin antenatally

›Delivery-room readiness matters even when no risk factor is present

›Antenatal planning

›Offer a discussion of elective caesarean after a previous shoulder dystocia, especially with a severe index event, neonatal injury, or a larger current estimated fetal weight

›Discuss caesarean when estimated fetal weight is 5000 g or more without diabetes, or 4500 g or more with diabetes, accepting the imprecision of the estimate

›Offer induction of labour at 37 to 39 weeks for suspected macrosomia, which reduces shoulder dystocia without increasing caesarean

›Optimise glycaemic control through pregnancy and labour

›Avoid mid-cavity or rotational operative vaginal delivery when macrosomia is suspected

›Intrapartum

›Ensure senior presence and a rehearsed team for any at-risk labour

›Do not use prophylactic McRoberts positioning, which does not prevent dystocia

›Treat slow second-stage progress as a warning sign

›Maternal complications to anticipate

›Postpartum haemorrhage, the most common, around 11%

›Obstetric anal sphincter injury, around 4%

›Symphyseal separation and transient femoral neuropathy from prolonged hyperflexion beyond about 15 minutes

›Uterine rupture, especially if fundal pressure was applied

›Bladder atony and urinary retention

›Post-traumatic stress, offer a structured debrief and follow-up

›Uterotonic choice and maternal disease

›Avoid ergometrine and methylergometrine in hypertension and pre-eclampsia

›Avoid carboprost in asthma

›Prefer oxytocin as first-line in nearly all situations

Geriatric

›Applicability

›Shoulder dystocia does not occur outside reproductive age, so this section covers the older obstetric patient and older caregivers

›Advanced maternal age of 35 and over, and especially 40 and over, raises gestational diabetes, macrosomia, and operative delivery, all of which raise shoulder dystocia risk

›Comorbidity effects

›Chronic hypertension is more common with age and rules out ergot alkaloids for haemorrhage

›Reduced cardiovascular reserve lowers the threshold for transfusion and critical care in postpartum haemorrhage

›Higher background venous thromboembolism risk means prophylaxis should resume promptly once bleeding has stopped

›Practical points

›Grand multiparity, associated with older age, independently raises macrosomia and uterine atony risk

›An older birth partner may need their own seating and monitoring during a prolonged resuscitation in the room

Pediatrics

›The neonate is the second patient and needs a parallel team

›Assign neonatal staff before delivery of the body

›Have the warmer, suction, and bag-mask checked and ready

›Brachial plexus birth injury

›Erb palsy, C5 to C6, an adducted internally rotated arm with an extended elbow, the waiter's tip posture, the most common pattern

›Klumpke palsy, C8 to T1, a clawed hand with preserved shoulder and elbow, sometimes with an ipsilateral Horner syndrome

›Total plexus palsy, a flail insensate arm, the worst prognosis

›Most injuries are neurapraxia and recover, refer if there is no biceps function by 3 to 6 months

›Some plexus injuries follow impaction of the posterior shoulder and are not caused by the accoucheur's traction

›Skeletal injury

›Clavicle fracture, crepitus and pseudoparalysis, analgesia and gentle handling, excellent prognosis

›Humeral shaft fracture, often after posterior arm delivery, immobilise against the chest, heals in 2 to 3 weeks

›Other nerve injury

›Phrenic nerve palsy, C3 to C5, presenting as respiratory distress, confirmed by ultrasound of diaphragmatic movement

›Facial nerve palsy, usually transient, protect the cornea

›Hypoxic-ischaemic encephalopathy

›Grade with the Sarnat system and screen with amplitude-integrated EEG

›Cool within 6 hours if 36 weeks or more with moderate or severe encephalopathy and an acidaemia or Apgar criterion met

›Treat seizures with phenobarbital 20 mg/kg IV loading

›Verify against current pediatric guideline before use

›Metabolic and respiratory

›Neonatal hypoglycaemia in the infant of a diabetic mother, feed early, check glucose at 30 to 60 minutes, treat below 2.6 mmol/l

›Pneumothorax from vigorous positive-pressure ventilation, transilluminate and image if the infant deteriorates

›Blood-borne virus exposure

›Hepatitis B immunoglobulin plus vaccine within 12 hours if the mother is surface-antigen positive

›Neonatal antiretroviral prophylaxis and avoidance of breastfeeding where safe alternatives exist if the mother is HIV positive

›Routine newborn care

›Vitamin K 1 mg IM to all infants

›Delayed cord clamping if the infant is vigorous, but never at the expense of resuscitation

10Background/b40

Epidemiology

›Incidence

›Complicates approximately 0.5% to 1% of vaginal deliveries, with a reported range of 0.2% to 3% depending on the definition

›Rises to roughly 5% to 9% when birthweight exceeds 4000 g in a diabetic mother, and higher above 4500 g

›About half of cases occur in infants under 4000 g, which is why prediction and prevention fail

›Recurrence

›Approximately 10% in a subsequent vaginal delivery

›Higher after a severe index event, prompting many families to choose elective caesarean

›Neonatal outcomes

›Brachial plexus injury in roughly 4% to 16%, of which fewer than 10% are permanent

›Clavicular or humeral fracture in roughly 2% to 10%, almost always healing without sequelae

›Hypoxic-ischaemic injury and perinatal death are rare, with risk rising sharply once the head-to-body interval exceeds 5 minutes

›Maternal outcomes

›Postpartum haemorrhage in around 11%

›Significant perineal trauma in around 4%

Pathophysiology

›The mechanics of impaction

›The bisacromial diameter fails to rotate from the anteroposterior into the oblique pelvic diameter, so the anterior shoulder catches on the symphysis

›Larger fetal size, a broader shoulder-to-head ratio in diabetes, and a rapid second stage all favour the shoulders arriving before rotation

›The oxygen clock

›After the head delivers, gas exchange depends on an uncompressed cord, and cord and fetal neck vessel compression begins at the moment of impaction

›Fetal pH falls at roughly 0.04 units per minute when the cord is compressed, faster than the uncomplicated rate

›A fetus with an abnormal pre-delivery tracing or growth restriction decompensates sooner

›Brachial plexus injury mechanism

›Stretch of the C5 to T1 roots

›Lateral traction on the head injures the plexus on the side of the anterior shoulder

›Impaction of the posterior shoulder on the sacral promontory can injure that plexus without any traction

›Neurapraxia recovers, while rupture and root avulsion do not without surgery

11Patient Discharge Instructions/pdi46

Maternal recovery and warning signs

›What to expect

›Perineal soreness, bruising, and pelvic girdle ache for days to a few weeks

›Gradual return of comfortable walking and sitting

›Recovery actions

›Pelvic floor exercises once comfortable

›Physiotherapy referral if pelvic pain limits walking

›Future pregnancy

›A future pregnancy carries recurrence of approximately 10%, tell the maternity team early so delivery can be planned

›Complete gestational diabetes screening if it was ever missed, and have early testing in the next pregnancy

Newborn follow-up and monitoring

›The affected arm

›Watch for steadily improving movement over days to weeks

›Keep the first specialist and physiotherapy appointments, since the timing of any surgery depends on early review

›Fractures

›A fractured collarbone or arm heals on its own in 2 to 3 weeks

›Handle the baby gently and support the arm when lifting

›Feeding and glucose

›Feed regularly and attend the glucose checks if the baby was large or the mother had diabetes

copy discharge instructions

›You had a shoulder dystocia during birth, meaning the baby's shoulder was briefly stuck after the head was born, and the team used position changes and hand maneuvers to release it

›Keep the written birth summary you were given, it lists exactly what happened and will guide care in a future pregnancy

›A future pregnancy carries a recurrence of approximately 10%, so tell your next maternity team about this birth

›For the mother, medicines

›Paracetamol 1 g up to four times a day, no more than 4 g in 24 hours

›Ibuprofen 400 mg with food up to three times a day, no more than 1200 mg in 24 hours, only if you were told it is safe for you

›Use ice packs on the perineum for 10 to 20 minutes at a time for the first 2 days

›For the mother, go to the emergency department or maternity unit now if you

12References/r29

Society guidelines

›American College of Obstetricians and Gynecologists

›ACOG Practice Bulletin Number 178, Shoulder Dystocia, 2017, reaffirmed

›ACOG Practice Bulletin Number 216, Macrosomia, 2020

›Royal College of Obstetricians and Gynaecologists

›Green-top Guideline Number 42, Shoulder Dystocia, second edition, 2012

›National Institute for Health and Care Excellence

›NICE Guideline NG235, Intrapartum care, 2023

›World Health Organization

›WHO recommendations on the prevention and treatment of postpartum haemorrhage, 2012 with later updates

›American Academy of Family Physicians

›Advanced Life Support in Obstetrics course manual, source of the HELPERR mnemonic

Landmark trials and evidence

›Boulvain and colleagues, The Lancet, 2015

›Induction of labour versus expectant management for suspected large-for-date fetuses reduced shoulder dystocia and associated morbidity without increasing caesarean

›WOMAN trial, The Lancet, 2017

›Tranexamic acid 1 g reduced death due to bleeding in postpartum haemorrhage, with greatest benefit within 3 hours of birth

›Draycott and colleagues, Obstetrics and Gynecology, 2008, and later PROMPT training reports

›Introduction of multi-professional shoulder dystocia simulation was followed by a sustained fall in brachial plexus injury

›Bruner and colleagues, Journal of Reproductive Medicine, 1998

›Case series describing the all-fours maneuver for shoulder dystocia

›Gonik and colleagues, and later Gherman and colleagues

›Biomechanical and clinical description of the McRoberts maneuver and its effect on the pelvic inlet and plexus stretch

Neonatal and resuscitation references

›Sarnat and Sarnat, Archives of Neurology, 1976

›Clinical and electroencephalographic staging of neonatal hypoxic-ischaemic encephalopathy

›American Academy of Pediatrics and American Heart Association

›Neonatal Resuscitation Program, eighth edition, 2021

Evidence & Review

Evidence & Review