OBS - Complications in Labour

Question 1

Shoulder Dystocia

Pathophysiology
Risk Factors
Clinical Features/Signs
Complications

Answer 1

1. ) Pathophysiology - impaction of the anterior fetal shoulder behind the maternal pubic symphysis OR of the posterior shoulder on the sacral promontory
   - delayed delivery of the shoulders –> fetal hypoxia
   - applying traction –> a brachial plexus injury
2. ) Risk Factors
   - pre-labour: previous hx, GDM/macrosomia, BMI >30, IOL
   - intrapartum: prolonged labour (1st or 2nd), secondary arrest (progress stops), augmentation w/ oxytocin, instrumental delivery
3. ) Clinical Features/Signs
   - difficulty in delivery of the fetal head or chin
   - failure of restitution: no external rotation so fetus remains in O-A position and doesn’t ‘look to the side’
   - ‘Turtle Neck‘ sign: fetal head slightly retracts back into the pelvis, so that the neck is no longer visible
4. ) Complications
   - maternal: 3rd/4th-degree tears (3-4%), PPH (11%)
   - fetal: humerus or clavicle fracture, brachial plexus injury –> Erb’s palsy, fetal hypoxia –> cerebral palsy

Question 2

Management of Shoulder Dystocia

General Advice
First Line Manoeuvres
Second Line (‘Internal’) Manoeuvres
Post-Delivery Management

Answer 2

1. ) General Advice - managed properly, the risk of brachial plexus injury can be almost eliminated
   - escalate: senior obstetrician/midwife, paediatrician
   - advise mother to stop pushing (worsens impaction)
   - avoid downwards traction on the fetal head, only use “routine” axial traction (head in line w/ the baby’s)
   - don’t apply fundal pressure (risk of uterine rupture)
   - consider episiotomy: won’t relieve the obstruction but can make access for manoeuvres easier
2. ) First Line Manoeuvres
   - McRoberts: hyperflex maternal hips to provide a posterior pelvic tilt to widen the pelvic outlet
   - then apply suprapubic pressure behind the anterior shoulder to disimpact it from the maternal symphysis
3. ) Second Line (‘Internal’) Manoeuvres
   - posterior arm: insert hand posteriorly into the sacral hollow and grasp the posterior arm to deliver
   - internal rotation (“corkscrew manoeuvre”): apply pressure in front of one shoulder and behind the other to move baby 180° or into an oblique position
   - if the above fail, roll the patient onto all fours (widens pelvic outlet) and repeat the internal manoeuvres
   - further manoeuvres (rarely used): symphysiotomy (cut pelvic symphysis), cleidotomy (fetal clavicle is fractured), Zavenelli (return head into the pelvis to do a C-section)
4. ) Post-Delivery Management
   - active management of the 3rd stage of labour
   - PR exam to exclude a 3rd/4th-degree tear
   - advise risk of recurrence with subsequent deliveries
   - consider physio review before discharge, due to increased risk of pelvic floor weakness, perineal tears, MSK pain and temporary nerve damage
   - paediatric review to assess for brachial plexus injury, humeral fracture or hypoxic brain injury

Question 3

Umbilical Cord Prolapse

Pathophysiology
Types of Umbilical Cord Prolapse
Clinical Features (and Differentials)
Management

Answer 3

1. ) Pathophysiology - umbilical cord descends through the cervix before (or with) the fetal presenting part
   - fetal hypoxia occurs via two main mechanisms:
   - occlusion: presenting part compresses onto the cord
   - arterial vasospasm: occurs due to cord exposure to the cold atmosphere –> ↓blood flow to the fetus
   - risk factors: amniotomy (ARM), breech (esp footling), unstable lie, polyhydramnios, prematurity
2. ) Types of Umbilical Cord Prolapse
   - occult (incomplete): cord descends alongside the presenting part and in the presence of ROM
   - overt (complete): cord descends past the presenting part and in the presence of ruptured membranes
   - cord presentation: the presence of the cord between the presenting part and the cervix, this can occur with or without intact membranes
3. ) Clinical Features (and Differentials)
   - signs of fetal distress on a CTG: decelerations, fetal bradycardia (strongly associated with cord prolapse)
   - confirmed by external inspection or on digital VE
   - consider an alternative diagnosis in the presence of PV bleeding or heavily blood-stained liquor w/ ROM:
   - placenta abruption or vasa praevia
4. ) Management - obstetric emergency (call for help)
   - avoid handling the cord to reduce vasospasm
   - manually lift the presenting part off the cord (VE)
   - place the mother on all fours OR left lateral position OR knee-chest position (whilst awaiting C-section)
   - consider tocolysis w/ terbutaline to stop contractions
   - emergency C-section (CAT-1) is indicated
   - vaginal delivery if fully dilated and delivery appears imminent, consider instrumental delivery if needed
   - in community: fill the maternal bladder with 500ml of normal saline via a catheter, arrange hospital transfer

Question 4

Uterine Rupture

Pathophysiology
Risk Factors
Clinical Features
Management

Answer 4

1. ) Pathophysiology - rupture of the myometrium
   - affects the overlying serosa and can extend to affect the bladder or broad ligament, 2 main types:
   - incomplete: overlying peritoneum is intact
   - complete: peritoneum is also torn, and the uterine contents can escape into the peritoneal cavity
   - both lead to significant bleeding, baby can enter the peritoneal cavity in a complete rupture
   - high mortality and morbidity for baby and mother
2. ) Risk Factors
   - VBAC (main), classical/vertical incisions
   - previous uterine surgery, obstruction of labour
   - ↑age, raised BMI, multiparity, multiple pregnancy
   - IOL (esp w/ prostaglandins) augmented w/ oxytocin
3. ) Clinical Features - initial features are non-specific
   - acutely unwell mother and an abnormal CTG
   - sudden severe abdo pain +/- shoulder tip pain
   - vaginal bleeding, ceasing of uterine contractions
   - may be regression of the fetal presenting part
   - palpation: scar tenderness and palpable fetal parts
   - if severe –> hypovolaemic shock (↑HR, ↓BP)
   - fetal distress or absent heart sounds
   - DDx: placental abruption, placenta/vasa praevia
4. ) Management - OBS emergency so call for help
   - USS for diagnosis in pre-labour setting: abnormal lie/presentation, haemoperitoneum, no uterine wall
   - continuous CTG in women at risk: changes in fetal HR, prolonged fetal bradycardia are early indicators
   - pathological CTG prompts a CAT1-section looking for a rupture, the uterus can be repaired or removed
   - invoke the Massive Obstetric Haemorrhage protocol: initiate A-E and fluid/blood resuscitation

Question 5

Amniotic Fluid Embolism

Pathophysiology
Clinical Features
Investigations
Management

Answer 5

1. ) Pathophysiology - amniotic fluid containing fetal tissue passes into the mother’s blood which triggers an immune reaction leading to a systemic illness
   - more similar to anaphylaxis, high mortality rate (20%)
   - usually occurs around labour and delivery
   - risk factors: ↑age, multiple pregnancy, IOL, C-section, instrumental delivery, eclampsia, polyhydramnios, uterine rupture, placenta praevia, placental abruption
2. ) Clinical Features - similar to anaphylaxis/sepsis
   - sudden onset shock, hypotension, hypoxia, seizures, confusion, cardiac arrest, fetal distress, DIC
   - difficult to confirm the diagnosis, differentials inc:
   - PE, anaphylaxis, sepsis, eclampsia, MI
3. ) Investigations
   - bloods: FBC, U+Es, ABG, clotting, Ca and Mg
   - ECG (ischaemia), CXR (pulmonary oedema)

4.) Management - OBS emergency so call for help
- call anaesthetics to arrange ITU admission
- rapid maternal resuscitation
- A-E assessment, high flow O2, fluid resus
- DIC should be managed with haematology
- continuous fetal monitoring until imminent delivery
- perimortem section in severe maternal compromise or cardiac arrest to facilitate CPR
- definitive diagnosis only confirmed on post mortem
showing fetal squamous cells along with debris in the pulmonary vasculature

Question 6

Perineal Tears

Risk Factors
Classification of Perineal Tears
Management
Complications
Perineal Massage and Episiotomy

Answer 6

1. ) Risk Factors
   - nulliparity, large babies (>4kg), shoulder dystocia
   - instrumental delivery, occipito-posterior position
   - Asian ethnicity
2. ) Classification of Perineal Tears
   - 1°: frenulum of the labia minora and superficial skin
   - 2°: inc perineal muscles but not the anal sphincter
   - 3°: inc anal sphincter but not the rectal mucosa, 3A affects <50% of external anal sphincter, 3B affects >50% 3C affects external and internal anal sphincter
   - 4°: includes the rectal mucosa
3. ) Management
   - 2°: requires sutures on the ward
   - 3°/4° tear will likely need repairing in theatre
   - broad-spectrum Abx to reduce the risk of infection
   - laxatives to reduce constipation/wound dehiscence once the tear has been closed
   - physio to reduce risk/severity of incontinence
   - symptomatic women after 3°/4° tears are offered an elective caesarean section in subsequent pregnancies
4. ) Complications
   - pain, bleeding, infection, wound dehiscence
   - long-term: incontinence (inc anal in 3°/4° tears), vesicovaginal fistula (rare), dyspareunia and sexual dysfunction, psychological and MH consequences
5. ) Perineal Massage and Episiotomy
   - perineal massages are used to reduce the risk of tears, involves massaging the perineum from 34wks onwards to stretch and prepare the tissues for delivery
   - an episiotomy is where the perineum is cut before delivery in anticipation of needing additional room for delivery of the baby (e.g. before forceps delivery)
   - episiotomies are done under LA, often a mediolateral episiotomy, the cut is sutured after delivery

Question 7

Primary Postpartum Haemorrhage

Definition
Aetiology and Risk Factors
Clinical Features
Investigations

Answer 7

1. ) Definition - the loss of >500 ml (>1L in C-section) of blood PV w/in 24hrs of delivery, classifications:
   - minor PPH is 500ml-1L blood loss
   - major PPH >1000ml, (moderate >1L, severe >2L)
2. ) Aetiology and Risk Factors - 4Ts
   - Tone: uterine atony (most common cause), RF: hx of PPH, >40, BMI >35, polyhydramnios, macrosomia, multiple pregnancy, placental praevia/abruption
   - Tissue: retention of placental tissue, preventing the uterus from contracting, 2nd most common cause
   - Trauma: damage during delivery, risk factors include: instrumental delivery, episiotomy, C-section
   - Thrombin: vascular (abruption, HTN, preeclampsia) or coagulopathies (vWF, haemophilia, ITP, DIC, HELLP)
3. ) Clinical Features - PV bleed is the main feature
   - haemodynamic instability: ↑HR, ↑RR, ↑CRT, ↓BP
   - hypotension: dizziness, palpitations, SOB
   - abdo exam: may show signs of uterine rupture
   - speculum: may show a local bleeding site
   - examine the placenta to ensure that the placenta is complete (a missing cotyledon or ragged membranes could both cause a PPH)
4. ) Investigations - bloods
   - FBC, U+Es, LFTs, coagulation profile
   - crossmatch 4-6 units of blood

Question 8

Management of Primary PPH

Immediate Management
Definitive Management of Uterine Atony
Definitive Management for Other Causes
Prevention

Answer 8

1. ) Immediate Management
   - teamwork: involve midwives, obstetricians, clinical haematologists, anaesthetists, blood banks, porters
   - monitoring: RR, O2 sats, HR, BP, temp every 15 mins, consider a catheter and insertion of a central line
   - resus: A-E: protect airway, 15L of 100% O2 through a non-rebreathe mask, fluid/blood resus, monitor GCS
   - trigger massive obstetric haemorrhage protocol once the bleeding exceeds 2000ml
2. ) Definitive Management of Uterine Atony
   - bimanual compression: stimulate uterine contraction, compress the anterior uterine wall using a fist and apply pressure on the abdomen (posterior uterus)
   - catheterisation (a full bladder prevents contractions)
   - pharmacological: uterotonics to ↑ uterine tonicity
   - surgical: 1°intrauterine balloon tamponade, haemostatic brace suturing (B-lynch suture around the uterus), bilateral uterine or internal iliac artery ligation, selective arterial embolization, hysterectomy (last resort)
3. ) Definitive Management for Other Causes
   - tissue: manual removal of the placenta under LA/GA, prophylactic abx, IV Oxytocin infusion after removal
   - trauma: primary repair of laceration, if uterine rupture: laparotomy and repair or hysterectomy
   - thrombin: correct any coagulation abnormalities with blood products with advice from haematology
4. ) Prevention
   - active management of 3rd stage w/ oxytocin
   - IV tranexamic acid during C-sections in the high-risk
   - treating anaemia during the antenatal period
   - labour with an empty bladder (better contractions)

Question 9

Pharmacological Management of Uterine Atony

Syntocinon
Ergometrine
Carboprost
Misoprostol

Answer 9

1. ) Syntocinon - synthetic oxytocin
   - slow injection followed by continuous IV infusion given as 40 units in 500 mls
   - contra: hypertonic uterus, severe CVS disease
   - side effects: N+V, headache, hypotension
2. ) Ergometrine (IV/IM) - acts on multiple receptor sites
   - contra: HTN, pre-eclampsia, vascular disease
   - side effects: hypertension, nausea, bradycardia
   - syntometrine is oxytocin + ergometrine
3. ) Carboprost (IM) - prostaglandin F2 analogue
   - contraindications: cardiac or pulmonary disease
   - side effects: bronchospasm, pulmonary oedema, HTN, cardiovascular collapse
4. ) Misoprostol (SL) - prostaglandin E1 analogue
   - side effects: diarrhoea

Question 10

Secondary Postpartum Haemorrhage

Definitions and Aetiology
Clinical Features
Investigations
Management

Answer 10

1. ) Definitions and Aetiology - excessive PV bleeding from 24hrs after delivery to 12wks postpartum
   - endometritis: RF inc: C-section, PROM, long labour
   - retained placental fragments or tissue
   - abnormal involution of the placental site: inadequate closure and sloughing of the spiral arteries
   - trophoblastic disease (very rare)
   - personal hx of secondary PPH is a strong risk factor
2. ) Clinical Features
   - excessive PV bleeding (not as bad as primary PPH)
   - may complain of intermittent spotting for days after delivery, with an occasional gush of fresh blood
   - 10% are massive haemorrhages –> shock
   - endometritis: fever/rigors, lower abdo pain or foul-smelling lochia (normal discharge from the uterus), lower abdominal tenderness on abdo examination
   - high uterus on exam is a sign of retained placenta
   - speculum: to assess the amount of bleeding
3. ) Investigations
   - haemodynamically unstable: resus is initial priority
   - bloods: FBC, CRP, U+Es, clotting, G+S, blood cultures
   - pelvic USS: helps diagnose retained placental tissue
   - endocervical and HVS for infection
4. ) Management
   - antibiotics: ampicillin + metronidazole +/- gentamicin in cases of endomyometritis or overt sepsis
   - uterotonics: to ↑ uterine contractions
   - surgical evacuation of retained POC: high risk of uterine perforation (softer/thinner uterus post-partum)
   - surgical measures for excessive/continuous bleeding, insertion of a balloon catheter may be effective

Question 11

Uterine Inversion

What is it?
Clinical Features
Management

Answer 11

1. ) What is it? - the fundus drops down through the uterine cavity and cervix, turning the uterus inside out
   - incomplete (partial): fundus does not descend as far as the introitus (opening of the vagina)
   - complete: descends through the introitus
   - may be due to pulling too hard on the umbilical cord during active management of the third stage of labour
2. ) Clinical Features
   - typically presents w/ a large PPH +/- shock/collapse
   - incomplete uterine inversion may be felt with a digital VE, a complete inversion may be seen at the introitus
3. ) Management - life-threatening obstetric emergency
   - Johnson manoeuvre: use hand/forearm to push the fundus back to the correct position for several mins, oxytocin is given for contractions to help hold in place
   - hydrostatic methods: ‘inflate’ the uterus with fluids
   - surgery: laparotomy is the last line
   - also manage the corresponding PPH