Labour & Delivery�Suwandi Dewapura�skdew4@student.monash.edu

Today’s Lecture

• Stages of labour
• Instrumental & Operative deliveries
• Birth trauma
• Intrapartum fetal monitoring
• Induction
• Vaginal birth after Caesarean (VBAC)

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Not covered here:

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• Mechanism of labour
• Physiology of labour
• OSCE-style management of labour (Hx, Ex)
• Analgesia in labour

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• Malpresentations (covered later today)

Stages of labour

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Stage 1:

0 🡪 10cm dilation

Active

Latent

A quick word about Rupture of Membranes (ROM):

• Rupture of amniotic sac
• Usually spontaneous (SROM), in first stage of labour
• However, can be delayed (during second stage)
• Can also be premature (PROM/PPROM) – not covered here.

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Stage 1:

0 🡪 10cm dilation

• Contractions are mild and infrequent
• Cervical dilation occurs at a slower rate (<1cm/hr)
• May last up to 14– 20 hours depending on parity

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• From 6cm to 10cm dilation
• Rate of dilation increases from latent phase
• (1.2-1.5 cms/hour)
• Duration: 2-3 hrs in multis; 4-6 hrs in primips

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Management of normal Stage 1:

• Analgesia as required
• Determine fetal position by examination
• Assess cervical dilation & descent of fetal head regularly (VE 4 hourly)
• +/- CTG
• +/- Amniotomy during active phase (not necessary if labour progressing well)

Active

Latent

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Active

Latent

Stage 1:

0 🡪 10cm dilation

Stage 2:

Fully dilated to birth of infant

During this stage:

• Regular contractions (increasing frequency & intensity)
• Crowning (appearance of fetal head at vaginal opening with contractions)

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Duration:

• <2 hrs for primips
• <1 hr for multis
• (+1 hr if epidural analgesia)

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Active

Passive

Stage 2:

Fully dilated to birth of infant

Presenting part descends through the pelvis (no urge to push)

Maternal effort to drive presenting part through birth canal

During this stage:

• Regular contractions (increasing frequency & intensity)
• Crowning (appearance of fetal head at vaginal opening with contractions)

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Duration:

• <2 hrs for primips
• <1 hr for multis
• (+1 hr if epidural analgesia)

Active

Latent

Stage 1:

0 🡪 10cm dilation

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Active

Passive

Stage 2:

Fully dilated to birth of infant

Management of normal Stage 2:

• Warm compresses, comfortable & safe positions
• Episiotomy if required

(indications include shoulder dystocia, instrumental delivery or vaginal breech)

• +/- Delay cord clamping at least 1 minute, unless evidence of compromise and need for neonatal resuscitation

Active

Latent

Stage 1:

0 🡪 10cm dilation

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Stage 3

Active

Passive

Stage 2:

Fully dilated to birth of infant

Stage 3:

Birth to expulsion of placenta

Active

Latent

Stage 1:

0 🡪 10cm dilation

During this stage:

• Contractions to expel the placenta
• Eventually, expulsion of placenta (usually with associated bleeding)

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Duration:

• 30 mins with Active Mx
• 60 mins with Physiological Mx (expulsion by maternal effort only)

Management of normal Stage 3:

• Fundal massage (induce contraction + stop bleeding)
• Active management to reduce risk of PPH

10 units oxytocin IM

Controlled cord traction (placenta separate on its own)

• Perform placental examination to ensure complete
• Repair perineal lacerations, if any
• Assess blood loss & manage appropriately

Management of prolonged labour

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Management of prolonged labour

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Management of prolonged labour

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Management of prolonged labour

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Induction of labour

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Induction of Labour (IOL)

Common indications

• Prolonged pregnancy
• FGR
• Pre-eclampsia & other hypertensive disorders
• Deteriorating maternal illness
• Diabetes mellitus
• PROM

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Contraindications

• Hx of uterine rupture
• Previous classical Caesarean or high-risk Caesarean
• Vasa/placenta praevia
• Malpresentation
• Cord prolapse
• Active genital herpes
• Non-reassuring FHR
• Any other contraindication to labour or vaginal birth

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Bishop’s Score

• Used to assess favourability of the cervix & whether induction will be successful
• Simplified Bishop’s Score: only looking at fetal station, cervical dilation and cervical effacement
• Modified Bishop’s Score: looks at five criteria

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If Bishop’s ≥5, cervix favourable for vaginal delivery.

Options for IOL

• Stretch & sweep (stimulates prostaglandin release)
• Cervical ripening
• Foley or Cook catheters (put pressure on cervix)
• Prostaglandins (e.g. Cervidil)
• ARM (increases pressure of fetal head on cervix)
• Only if cervix partially dilated & completely effaced, and fetal head well-applied
• Synthetic oxytocin (Syntocinon)

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Complications of IOL with Syntocinon

• Excessive uterine activity & hyperstimulation
• Uterine rupture
• Water intoxication with high dose regimen or prolonged periods of use (oxytocin has an ADH-like effect)

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Instrumental delivery

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Indications for Instrumental Delivery

• Confirmed/suspected fetal compromise
• Lack of advancement of presenting part & maternal tiredness
• Shorten & reduce the effects of second stage of labour if there are concurrent medical conditions
• E.g. CHF NYHA Class III or IV, hypertensive crisis, myasthenia gravis, spinal cord injury & risk of autonomic dysreflexia, proliferative retinopathy

Prerequisites for instrumental delivery

• Adequate uterine contractions
• Fetal head not palpable abdominally
• Station of presenting part below ischial spines
• Knowledge of exact position of head
• Vertex presentation
• Cervix fully dilated, membranes ruptured
• Adequate pelvis (no CPD)
• Empty bladder

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Both require:

• Sufficiently large birth canal
• Fully dilated cervix
• An engaged fetal head
• Adequate uterine contractions

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Both can be used for management of:

• Prolonged second stage
• Non-reassuring CTG
• In the instance of maternal exhaustion

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Both contraindicated if:

• Fetal bleeding disorder
• Predisposition to fractures

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• Can be used for breech presentation
• Can use Neville-Barnes for face presentations

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• Less likely to sustain scalp injuries
• Can’t dislodge during delivery

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• Requires more space than vacuum
• Higher risk of perineal trauma / tears

• Not used for breech presentation
• Not for face presentations

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• Risk of scalp injuries (C/I before 34 weeks)
• Can dislodge during delivery

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• Doesn’t require much space
• Lower risk of perineal tears

Complications of Instrumental Delivery

Forceps

• Mother: lacerations to the cervix & vagina
• Fetus: scalp lacerations and trauma to the head

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Vacuum

• Mother: lacerations/haematomas
• Fetus:
• Cephalohaematoma
• Subgaleal haematoma (life-threatening)
• Intracranial haemorrhage (life-threatening)

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Birth trauma

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Chignon (‘artificial caput succedaneum’)

• Caused by collection of interstitial fluid and small haemorrhages, due to application of vacuum cup
• May cross suture lines
• Resolves within ~18hrs of birth
• No long-term issues

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Intrapartum fetal monitoring

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Impact of labour on the fetus

• With each contraction, placental blood flow and oxygen transfer are temporarily interrupted
• Healthy fetuses can deal with this, but if already compromised before labour, may cause further problems
• Insufficient oxygen delivery 🡪 switch to anaerobic metabolism 🡪 lactic acid & H⁺ ions 🡪 can lead to metabolic acidosis
• Possible effects include neurological injury, fetal death

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Fetal assessment in labour

• Colour of liquor (?fresh meconium ?heavy bleeding)
• Fetal movement evaluation
• Continuous external monitoring (CTG)
• Doppler ultrasound
• Fetal blood sampling

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When to initiate continuous CTG

• When risk factors for fetal compromise identified
• Use of IV syntocinon
• Commence before epidural to establish baseline (and continue)

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Baseline

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Baseline: Mean FHR when stable

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Determined over 5-10 minutes.

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Normal: 110-160 bpm

• Lower in the preterm fetus

Baseline variability

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Baseline variability: minor FHR fluctuations.

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Measure as bpm difference between highest peak & lowest trough in 1 minute

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Normal/moderate: 5-25 bpm

Reduced/minimal: 3 – 5 bpm

Absent: <3 bpm

Increased/marked: >25 bpm

Accelerations & Decelerations

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Accelerations

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Accelerations: Transient increase in FHR of ≥15 bpm above baseline for ≥15 seconds (less than 10 mins)

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Presence of 2+ accelerations in 20 minutes indicates a reactive FHR.

Decelerations

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Decelerations: transient decrease in FHR of ≥15 bpm below baseline for ≥15 seconds.

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Decelerations are interpreted in relation to contractions.

Early decelerations

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Early decelerations:

• Uniform, repetitive, slow-onset
• Occur early in contraction and return to baseline by end of contraction.

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Aetiology: Contraction compresses the fetal head, causing a vagal response.

Variable decelerations

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Variable decelerations:

• Repetitive or intermittent
• Rapid onset and recovery
• Variable relationship with contractions, although most commonly simultaneous with contractions

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Aetiology: compression of cord / cord prolapse

Late decelerations

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Late decelerations:

• uniform, repetitive, usually slow-onset, at the middle to end of contraction
• Lowest point >20 seconds after peak and ending after contraction

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Aetiology: placental insufficiency, causing hypoxia & acidosis.

Prolonged decelerations

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Prolonged deceleration: decrease of ≥15 bpm for longer than 90 seconds but less than 5 mins.

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Aetiology:

• Same as for variable & late decelerations, but lasting longer and more severe.

CTG Features

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Features of reassuring CTG:

• Baseline of 110 - 160bpm
• Baseline variability of 5-25 bpm
• Absence of decelerations

In labour, we are less worried about:

• Absence of accelerations
• Simple variable decelerations
• Early decelerations

When to worry:

• Fetal tachycardia or bradycardia
• Loss of baseline variability
• Recurrent variable decelerations or late decelerations

Responding to an abnormal CTG

• Reposition – left lateral position
• IV fluids if hypotensive
• Manual elevation of fetal head
• Consider VE to exclude cord prolapse
• Cease oxytocin, remove prostaglandin
• Delay active pushing during 2^nd stage of labour
• Consider tocolytics
• Emergency Caesarean if initial steps unsuccessful, or if significant fetal acidosis / compromise suspected.

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Caesarean Section

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Types of Caesarean Section

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This slide is just for understanding!

Indications for Caesarean Section

• Elective
• Traditionally where labour & delivery may be detrimental to mother & fetus
• Increasingly more women requesting for other reasons / personal preference
• Emergency, most common indications are:
• Failure to progress through first stage of labour
• Fetal distress
• Abnormal lie or malpresentation at start of labour

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Complications

• Maternal
• Bleeding
• Thromboembolism
• Injury to surrounding organs (bowel, bladder)
• Infection
• Complications for future pregnancies

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Impact of Caesarean on future pregnancies

• Greater risk of uterine dehiscence and rupture
• So future pregnancies recommended to be Caesareans as well, in many cases
• Women who have had 2* or more Caesareans should have Caesareans for all future pregnancies
• *3 according to PROMPT guidelines
• Increased risk of placental adherence in future pregnancies, requiring a hysterectomy

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Vaginal Birth After Caesarean �(VBAC)

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Overview of VBAC

• Avoiding major surgery & multiple Caesareans in future pregnancies
• Able to mobilise & leave hospital sooner
• Able to have a vaginal birth if patient wishes

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• 20-30% of women attempting VBAC will need Caesarean
• Attempting VBAC carries an additional risk of uterine scar rupture and other complications

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Complications of VBAC

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Complications of VBAC

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Uterine Rupture

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Pathophysiology: uterus becomes distended and subsequently

ruptures.

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Presentation:

- Maternal signs: severe abdo pain, PV bleeding, contractions stop

- Fetal signs: concerning CTG / decreased FHR, loss of station

- Maternal & fetal compromise

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Many other complications of VBAC are due to uterine rupture.

Complications of VBAC

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Hypoxic-ischaemic encephalopathy

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- Neurological changes due to poor oxygen delivery perfusing

the fetal brain

- Manifests during first few days after birth

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- Presentation: organ dysfunction (heart, lungs, kidneys, liver,

blood), seizures, lethargy, unresponsive.

To VBAC or not to VBAC?

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Contraindications for VBAC

3+ previous C/S, need for IOL, previous labour suggesting cephalopelvic disproportion, previous classical Caesarean scar, previous uterine rupture, malpresentation (e.g. breech)

Advice to improve VBAC Outcomes

• Inter-pregnancy interval of at least 12 months
• Better outcomes with further increased interval (see Monash PROMPT ‘Birth after a previous caesarean section’ guideline)
• Weight reduction for overweight & obese patients
• Manage delivery in obstetric unit with trained staff and continuous monitoring of maternal & fetal wellbeing

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Management of VBAC

• CTG monitoring & regular VEs throughout labour
• IV cannula
• FBE, Group & Hold
• Be careful with oxytocin (Consultant approval at Monash)
• Do not use prostaglandins
• Monitor for signs of uterine rupture and move to Caesarean if necessary

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Sources & Acknowledgements

• O&G – An Evidence-Based Guide
• Obstetrics by Ten Teachers 19E
• PROMPT Guidelines
• Monash Dept. Obstetrics & Gynaecology
• RANZCOG Guidelines
• AMBOSS
• WHISM Online Resources

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THANKS!

Any questions?

Please feel free to email me ☺

skdew4@student.monash.edu

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