Management of Labour and Delivery Flashcards
Describe the 1st stage of labour.
- Onset of labour, until the cervix of fully dilated.
- Latent: painful contractions, where there is some cervical effacement and dilatation up to 4cm.
- Established: painful contractions and progessive cervical dilatation from 4cm.
Describe the 2nd stage of labour.
- From full cervical dilation, until the baby / baby head is delivered.
Describe the 3rd stage of labour.
- From delivery of the baby, until delivery of the placenta and membranes.
Describe the observations made using a partogram.
- Graphical display of intrapartum information.
- Allows for assessment of the:
- Power
- Frequency and duration of contractions
- Strength - remains subjective
- Passenger
- Foetal heart monitoring
- Position / station / moulding / caput
- Passage
- Effacement and dilation of the cervix
- Power
- Commence following accurate diagnosis of established labour
- Progress in labour
- Action lines
Explain the difference between induction and augmentation of labour.
-
Induction of labour:
- The process of starting labour
-
Augmentation of labour:
-
Process of accelerating labour which is already underway:
- Pre-Labour rupture of membranes
- Delay in 1st / 2nd stage of labour
-
Process of accelerating labour which is already underway:
What are the indications for induction or augmentation of labour?
- Prolonged pregnancy
- In 5-10% of women pregnancies continue beyond 42 weeks.
- Risk of perinatal death.
- Maternal DM
- Twin pregnancy
- Pre-term rupture of membranes
- Foetal growth restriction / placental insufficiency
- Hypertensive disorders
- Maternal medical disorders (renal /cardiac)
- Maternal age
- Reduced foetal movements
- Maternal request
What are the pharmacological methods of induction of labour?
- Prostaglandins (PGE2)
- Promote cervical ripening and stimulate uterine contraction.
- Vaginal route has fewest side effects.
- Gel / tablet / sustained release pessary.
- Greater risk of hyperstimulation.
- Syntocinon
- ‘Synthetic’ oxytocin
- Stimulates uterine contraction
- Only used following amniotomy
- IV infusion / dose titration to achieve contractions 4:10
What are the mechanical methods of inducing / augmenting labour?
-
Membrane sweep
- May double incidence of onset of spontaneous labour if carried out after 40/40.
-
Amniotomy (ARM - artificial rupture of membranes)
- Favourable cervix
- Also used to augment labour
- Allows assessment of the colour of liquor
- More likely to require oxytocin augmentation
- Head should be engaged or there is risk of cord prolapse.
-
Other
- Balloon
- Laminaria tents
Describe the cervical scoring system and how this determines which procedure should be carried out.
-
Assess favourability of the cervix.
- Score <8 = unfavourable cervix → ripen with PG.
- Score 8+ = favourable cervix → proceed with amniotomy.
What are the complications of induction and augmentation of labour?
- Uterine hyperstimulation (1-5%)
- Foetal distress
- Remove stimulus / role of tocolysis
- Labour experience
- Increased obstetric intervention
- Epidural
- Assisted vaginal delivery
- No increased risk of C-section
- Uterine rupture
- Caution in the presence of previous uterine surgery, especially with prostaglandins
- Failure / repeat courses
What are the methods of pain relief used during delivery?
- Non-pharmcological
-
Pharmacological:
- Inhaled
- Opioid
- Regional
-
Delivery
-
Local anaesthetic
- Perineal
- Pudendal
- Regional
- GA
-
Local anaesthetic
What are the non-pharmacological methods of pain relief used in labour?
- Maternal support
- 1:1 care in labour
- Requires less analgesia, higher SVD rate, better experience in labour.
- Birthing pools
- Reduce the need for regional anaesthesia
- Caution if the mother has had opioid analgesics
- Breathing and relaxation techniques / accupuncture / hypnosis / massage / aromatherapy / TENS.
- Limited evidence to support use.
- 1:1 care in labour
Describe the use of Entonox in labour.
- 50:50 mixture of O2 and nitrous oxide
- Commonly used
- Not a potent analgesic
- Generally very safe to use
- Adverse effect
- Nausea
- Vomiting
- Drowsiness
- Light-headedness
Describe the use of opioid analgesics in labour.
- Diamorphine 5-10mg
- Tend to have a limited effect during labour
- Adverse effects:
- Maternal
- Nausea and vomiting (administer with anti-emetic)
- Drowsiness
- Neonatal
- Drowsiness / respiratory depression (ideally do not administer within 3-4 hours of delivery)
- Maternal
- Continuous IV infusion
- Remifentanil
- Short acting
- PCA
What are the factors involved in prescribing epidural anaesthesia during labour?
- Regional anaesthesia = epidural.
- More effective than parenteral opioids.
- Prolonged second stage
- Increases AVD
- No increase in lower uterine segment C-section
- Increase in malabsorption
- Top-up
- Obstetric intervention
- Side effects:
- Hypotension
- Pyrexia / pruritis
What are the factors involved in prescribing spinal anaesthesia during labour?
- Regional anaesthesia = spinal.
- Predominantly used for obstetric intervention
- Denser block than epidural
- Single shot injection, lasts 2-4 hours
- Side effects:
- Hypotension
- Pyrexia / pruritis
- High block
What are the risks associated with GA during labour?
- Higher risks in the pregnant population compared to the non-pregnant population.
- Tissue oedema
- Reduced gastro-oesophageal tone
- Increased intra-abdominal pressure
- Delayed gastric emptying
- Increased gastric acidity
What is the aim of intrapartum foetal monitoring?
- The ultimate aim of intrapartum foetal monitoring is the prevention of death and morbidity due to hypoxia.
- Hypoxaemia / hypoxia cause changes in the foetal heart rate pattern.
- Changes in the foetal heart pattern during labour are very common, but significant foetal hypoxia is relatively rare.
- C-section rates tend to rise by ~30% with the use of ‘routine’ monitoring, due to over-diagnosis of foetal distress.
- Can restrict mobility in labour.
What factors affect the foetal heart rate?
- The heart has an intrinsic rate.
- Nerve supply
- Rate is reduced by the vagus nerve (parasympathetic)
- Rate is increased by the sympathetic supply
- Circulating catecholamines
- Adrenal
- CNS activity
- Changes in foetal blood pressure
- Changes in foetal blood gas levels (O2, CO2, pH)
Describe the use of intermittent auscultation in labour.
- ‘Low risk’ women in established labour.
- Doppler USS
- Performed immediately after a contraction for at least 1 minute, at least every 15 minutes.
- Recorded as a single rate, noting accelerations or decelerations if heard.
- Palpate maternal pulse.
- Act upon any changes:
- Rising baseline rate
- Decelerations
- Assess the patient (position, hydration, contraction (frequency / tone), maternal observations).
- Increase frequency of auscultation.
- Continuous CTG
What are the indications for continuous CTG monitoring in labour?
- Maternal tachycardia
- Maternal pyrexia
- Suspected chorioamnionitis or sepsis
- Presence of significant meconium
- Fresh vaginal bleeding
- Hypertension / proteinuria
- Confirmed delay in labour (1st or 2nd stage)
- Hypertonus or tachysystole
- Oxytocin use
- Reported pain outwith the normal
- Preterm
- Multiple pregnancy