Abnormal Labour Flashcards
What binds the vertex?
Anterior and posterior fontanelles
Parietal eminences
What can cause an abnormal labour?
Malpresentation; non-vertex Malposition; OP or OT Preterm <37 weeks Post-term >42 weeks Obstruction Foetal distress
What are the 3 forms of breech?
Complete; legs folded with feet at the level of baby’s bottom
Footling breech; one or both feet point downwards so legs emerge first
Frank; legs point up with feet by babys head to bottom emerges first
What is the commonest variant of breech?
Frank
What are complications of breech?
Cord prolapse
Head entrapment
5% overall risk of foetal injury when breech delivered vaginally
What percentage of term babies are breech?
4%
What are the 3 forms of malpresentation?
Breech; 3 types
Transverse
Shoulder/arm
How can the head present if non-vertex?
Face presentation; if mental anterior can be delivered vaginally
Brow presentation; c/s
When is a birth termed preterm?
<37 weeks
Why can hyperstimulation resulting in a quick labour result in foetal distress?
If there is no gap between contractions, the placental vascular tree won’t have time to refill and therefore foetal hypoxia/ distress can occur
What forms of analgesia are available for labouring women?
Support Massage/ relaxation Inhalation; entonox TENS (T10-L1, S2-4) Water immersion IM opiate analgesia; diamorph IV remifentanil PCA Regional
When is IV remifentanil PCA utilised?
Gives short lasting bolus at peak of contraction
Good for women whose labours are progressing too quickly for a regional anaesthesia
Why is labour painful?
Compression of para-cervical nerves
Myometrial hypoxia
What issues can an epidural have on labour progression?
May inhibit progress during stage 2
Does NOT impair uterine activity
Complications of epidural anaesthesia?
Hypotension Dural puncture Headache High block; resp depression Atonic bladder
What is injected in through an epidural?
Low conc LA with opioid; 10-15ml bupivacaine with fentanyl
What is the purpose of the 1st test dose?
To endure that inadvertent intrathecal injection has not occured
What are the risks of an obstructed labour?
Sepsis; lots of vaginal exams Uterine rupture; multiparous women Obstructed AKI PPH Fistula formation Foetal asphyxia Neonatal sepsis
How is progress assessed in labour?
Cervical dilation
Descent of presenting part
What are signs of an obstructed labour?
Excessive moulding Caput Anuria Haematuria Vulval oedema
What is considered failure to progress in stage 1 of active labour?
Nulliparous and parous; <2cm in 4 hours
Parous women really should be a little quicker than this
When can you perform an instrumental delivery?
0 or + station
10cm dilated
What are the 3 Ps of failure to progress?
Power
Passage
Passenger
What can result in reduced power causing failure to progress?
Inadequate contractions; frequency +/- strength
What can result in an inadequate passage for a baby resulting in failure to progress?
Short stature of mother
Trauma
Shape; not gynaecoid (anthropoid or android)
What problems with the baby can result in failure to progress?
Macrosomia
Malposition
How many contractions are expected per 10 mins?
3 to 4
Duration of 40-50 seconds
What is the smallest diameter of the foetal head?
Suboccipito-bregmatic = 9.5cm
Submentobregmatic; 9.5cm
What is the biggest diameter at the pelvic inlet and outlet respectively?
Inlet; transverse diameter = 13.5cm
Outlet; AP diameter; 13.5cm
What are the different measurements for a vertex, OP, deflexed OP, brow and face presentation?
Vertex; suboccipito-bregmatic = 9.5 cm OP; suboccipito-frontal = 10 cm Deflexed OP; occipitofrontal = 11.5cm Brow = occipitomental 13cm Face; submentobregmatic = 9.5cm
What is the commonest reason why babies don’t progress?
Suboptimal flexion of the head
What does the partogram measure?
Foetal HR Amniotic fluid Cervical dilatation Descent Contractions Obstruction = moulding Maternal observations
What can be given in the 1st stage of labour to assist with failure to progress?
IVI syntocinon
When is the foetal heart measured in stage 1 of labour?
During and after a contraction
Every 15 mins
When is the foetal heart rate measured in stage 2 of labour?
At least every 5 mins during and after a contraction for 1 whole minute
Check mat pulse at least every 15 mins
What is included within the intrapartum foetal assessment?
Foetal HR - either pinnards, doppler or CTG
Colour of amniotic fluid
What are risk factors for foetal hypoxia?
Small foetus Pre-term/ post dates Antepartum haemorrhage Hypertension/ PET Diabetes Meconium Epidural analgesia VBAC PROM >24 hrs Sepsis (temp >38) Induction/ augmentation of labour
What is required if there are risk factors for foetal hypoxia?
CTG throughout labour
What can cause acute foetal distress?
Abruption Vasa praevia Cord prolapse Uterine rupture Foeto-maternal haemorrhage Uterine hyperstimulation Regional analgesia
What is vasa praevia?
A condition in which fetal blood vessels cross or run near the internal opening of the uterus. These vessels are at risk of rupture when the supporting membranes rupture, as they are unsupported by the umbilical cord or placental tissue
What can cause chronic foetal distress?
Placental insufficiency
Foetal anaemia
Can a CTG monitor the strength of contractions?
NO; only the frequency
What should be assessed when reviewing the CTG?
Baseline foetal heart rate
Baseline variability
Presence or absence of decelerations
Presence of accelerations
What is a normal baseline foetal HR?
110-150
Tachy >150
Brady <110 (although only really worried when below 90)
What is normal variability?
5-25 bmp
Reduced; <5
Saltatory >25
Complete loss = BAD
What are normal foetal accelerations?
Really reassuring to see accelerations
Rise of 15 beats above baseline for at least 15 seconds
In a 40 min period; want to see 2 accelerations
What is a normal deceleration?
Early with contractions but rise very quickly to baseline
What is a worrying deceleration?
Late; after peak of contraction
Broad
Slow to recover to baseline HR
How is a CTG classified?
Normal
Suspicious
Pathological
What is hypoxia characterised by on a CTG?
Loss of accelerations
Repetitive deeper and wider decelerations
Rising foetal baseline HR
Loss of variability
What is an acronym to CTG interpretation?
Dr C Bravado Determine Risk Contractions Baseline R Ate Variability Accelerations Decelerations Overall impression
What makes a CTG pathological?
More than 2 abnormal features
How is foetal distress managed?
Change maternal position; left lateral IV fluids Stop syntocinon Scalp stimulation Consider tocolysis; terbutaline 250 mcg s/c Maternal assessment; pulse, BP, abdo, VE Foetal blood sampling Operative delivery; category 1
How quickly must a category 1 delivery be performed in?
30 mins
What is foetal blood sampling?
Prick from foetal scalp
Look at pH to determine if foetus is hypoxic and acidotic = BAD
What is a normal foetal scalp pH?
> 7.25
What is a borderline scalp pH?
7.20 - 7.25; repeat in 30 mins
What is an abnormal foetal scalp pH?
<7.20; DELIVER
What are the methods for an operative/ instrumental vaginal delivery?
Forceps
Vontouse
What are the “standard” indications for an instrumental delivery?
Delay; failure to progress at stage 2
Foetal distress
What are the “special” indications for an instrumental delivery?
Maternal cardiac disease; pushing may be dangerous
Severe PET/ eclampsia
Intra-partum haemorrhage
Umbilical cord prolapse at stage 2
What is the max time limit on the duration of stage 2 in a primigravida woman?
No epidural; 2hrs
Epidural; 3hrs
What is the max time limit on the duration of stage 2 in a multip woman?
No epidural; 1hr
Epidural; 2hr
What are the advantages of ventouse?
No anaesthesia needed
Reduced vaginal trauma
Reduced perineal pain
What are the disadvantages of a ventouse?
Increased rates of failure
Increased risk of cephalohematoma
Increased risk of retinal haemorrhage
Increased maternal worry
Difference between forceps and ventouse?
Forceps; more damage to mother
Ventouse; more damage to baby
BUT
No difference in c/s rates, apgar score or long term outcomes
What are the main indications for a c/s?
Previous c/s Foetal distress Failure to progress Breech Maternal request
Risks assoc with c/s?
Sepsis Haemorrhage VTE Trauma TTN Subfertility Regret Complications in future pregnancy
