Labour Flashcards
What is a birth plan?
Record of what woman would like to happen during labour and after birth.
What factors must be considered when making a birth plan?
PMH
Circumstances
Services available in area
ICE
What are the hormonal influences on the initiation of labour?
Change in oestregen:progesterone ratio (increase oestrogen)
Foetal adrenals and pituitary hormones (oxytocin)
Foetal cortisol
What are the physical influences on the initiation of labour?
Myometrial stretch increases excitability of myometria fibres
Mechanical stretch of cervix and stripping of foetal membranes
Ferguson’s Reflex
Pulmonary surfactant secretion into amniotic fluid
What is Ferguson’s Reflex?
Neuroendocrine reflex by which contractions are sustained by pressure of cervix/vaginal walls
How does oxytocin influence initiation of labour?
initiates and sustains contractions, and promotes prostaglandin release at decidual tissue
What is the function of liquor?
Nurture and protect foetus
Facilitates movement
When does rupture of membranes occur?
Can occur: Preterm Pre-labour (typical) First stage (typical0 Second stage Born in caul
What two cervical changes occur during labour?
Softening
Ripening
What happens during cervical softening?
Increased hyaluronic acid gives increase in molecules amongst collagen fibres, decreasing bridging and therefore decreasing firmness
What happens during cervical ripening? (x4)
Decrease collagen fibre alignment
Decrease collagen fibre strength
Decrease tensile strength of cervical matrix
Increase in cervical decorin (dermatan sulphate proteoglycan 2)
What does the Bishop’s Score measure?
If it is safe to induce labour, via: Cervical position Cervical consistency Effacement dilatation Station in pelvis
What are the two phases of first stage of labour, and what characterises these?
Latent (3-4cm dilatation)
Active (4-10cm dilatation)
What cm is full dilatation?
10cm
What is the normal length of the second stage of labour?
Nulliparous - 3 hours with epidural, 2 hours without
Multiparous - 2 hours with epidural, 1 hour without
How long does the third stage of labour normally last?
Average - 10 mins
Range - 3 mins - 1 hour
What is first line active management for removal of placenta/membranes?
Oxytocin and controlled cord traction
What are Braxton Hicks?
False labour contractions - tightening of uterine muscles, do not increase in frequency or intensity
Resolve with ambulation or change in activity
What is the hormonal stimulant for labour contractions?
Oxytocin
How do contractions physically expel the foetus?
Tighten at the fundus to push baby into the birth canal
How are true labour contractions characterised?
Frequency, duration, intensity
Fundal dominance
Regular pattern
Frequency increasing
Duration initially 10-15 sec, builds up to 45
Intensity - increasing over time (mild -> moderate -> strong)
What are the three key factors for smooth progression of labour?
Power of contractions
Maternal Pelvis
Foetal factors
(3Ps: Power, Passage, Passenger)
Where in the uterus is the density of smooth muscle myocytes the greatest?
Fundus
Where is the uterine pacemaker located?
Tubal ostia (bilateral)
How does uterine polarity aid labour?
Upper segments of uterus contract and retract, while lower segments and cervix stretch, dilate and relax
Pushes baby downwards into birth canal.
What are the three types of pelvis, and which is the most preferable?
Anthropoid
Gynaecoid - most preferable
Android
What are the characteristics of an anthropoid pelvis?
Oval shaped inlet, large AP diameter, smaller transverse diameter
What are the characteristics of an android pelvis?
Triangular or heart shaped inlet (narrower at front)
African-Caribbean women are of higher risk of Anthropoid pelvic - true/false.?
False - they are at higher risk of Android pelvis
What 5 cervical factors influence onset of labour?
Effacement Dilatation Firmness Position Level of presenting part/station
What is the normal foetal position for labour?
Longitudinal lie
Cephalic presentation
Vertex presenting
Occipito-anterior or occipito-transverse
What are the abnormal foetal positions for labour? (x4)
Breech position
Oblique lie
Transverse lie
Occipito-posterior position
What during vaginal examination determines the foetal position?
Position of fontanelles
What is a partogram?
Graphic record of key maternal and foetal data, contained on one sheet, used to assess the progress of labour
What are the 7 cardinal movements of the baby’s head in labour?
- Engagement
- Descent
- Flexion
- Internal rotation
- Crowning and extension
- Restitution and external rotation
- Expulsion (anterior shoulder first)
What is the purpose of an episiotomy during crowning?
Prevent damage to anal sphincters
What is crowning?
The largest diameter of the head is encircled by the vulval ring
Cord clamping should be performed immediately following birth - T/F?
False - delayed cord clamping has shown better red blood cell flow to vital organs, less anaemia and increased duration of early breastfeeding
What are the benefits of skin-to-skin following labour, and what are the current guidelines for time?
Keeps baby warm and calm
Improves transition to life outside the womb
Improves longitudinal breastfeeding
guidelines = ~1 hour uninterrupted
When does third stage of labour usually occur?
5-10 minutes after delivery (normal < 30 mins)
At what plane does placental separation occur?
Spongy layer of decidua basalis
What are the two types of placental separation, and what is the mechanism of each? (x2)
Matthew Duncan - starts at the periphery (most common)
Shultz - starts at central aspect
What is the standard active management during third stage of labour?
Prophylactic Syntometerine (ergometrine + oxytocin)
Cord clamping and cutting
Controlled cord traction
Bladder emptying
What volume of blood loss is considered normal during labour?
< 500 mls
What physiological mechanisms maintain haemostasis during labour?
Tonic contraction (lattice pattern of uterine muscles strangulates the vessels)
Thrombosis of torn vessel ends (hypercoagulable state)
Myo-tamponade opposition of anterior/posterior walls
What is puerperium, and how long does it normally last?
Period of repair and recovery
~6 weeks
What is Lochia?
vaginal discharge containing blood mucus, and endometrial castings lasing ~2 weeks after birth
What are the three types of lochia, and what is the usual timeline for each?
Rubra (fresh red blood) 3-4 days
Serosa (brownish and watery) 4-14 days
Alba (yellow) 10-20 days
What uterine changes occur following birth?
Involution
Reduction in weight
Fundal height
Endometrial regeneration
How is lactation initiated following labour?
Placental expulsion + decrease in Oestrogen and Progesterone
O+P inhibit prolactin release so reduction in these allows for prolactin to activate mammary gland cells
What component of breast milk contains important immunological effects for baby?
Colostrum
What are the 7 reasons for abnormal labour?
- Too early (<37 weeks)
- Too late (induction at >42 weeks)
- Too painful (requires anaesthetist)
- Too long (failure to progress)
- Too quick (hyperstimulation)
- Foteal concerns e.g. hypoxia, sepsis
- Incorrect presentation
Which type of breech is characterised by both legs folded up with the feet at the level of the baby’s bum?
Complete breech
Which type of breech is characterised by one or both feel pointing downwards?
Footling
Which type of breech are the legs pointing upwards (so bum emerges first)?
Frank (most common)
What are the complications of transverse presentation?
Prolonged labour Rupture Maternal death (rare in UK)
What are the side effects of epidural anaesthesia?
Hypotension Dural puncture Headache High block Atonic bladder Reduced mobility Prolonged second stage of labour - increased chance of operative birth
At what level is the epidural injected into?
Between L3 and L4
What are the risks of obstruction to labour?
Sepsis Uterine rupture Obstructed AKI Postpartum haemorrhage Fistula formation Foetal asphyxia Neonatal sepsis
What are signs of obstruction of labour?
Moulding Caput Anuria Haematuria Vulval Oedema
What are the average dimensions of the pelvic inlet and outlet?
Inlet - 13.5cm x 11cm
Outlet - 11cm x 13.5cm
Which presentation most commonly causes slow progress in labour?
Occipito-posterior (OP)
What intrapartum foetal assessments for hypoxia are made?
Doppler auscultation
Electronic monitoring (CTG)
Colour of amniotic fluid
What are the risk factors for foetal hypoxia?
Small foetus Pre-term/post dates Antepartum haemorrage HTN/pre-eclampsia Diabetes Meconium Epidural VBAC PROM > 24 hours Sepsis Induction of labour
Presence of any one RF for foetal hypoxia is indicative for…
continuous foetal heart monitoring
What are acute causes of foetal hypoxia?
Uterine hyperstimulation Abruption Cord prolapse Uterine rupture Foeto-maternal haemorrhage Regional anaesthesia Vasa Praevia
What are chronic causes of foetal hypoxia?
Placental insufficiency
Foetal anaemia
How do you interpret CTG?
hint - pneumonia
DR C BRAVADO
Determine Risk Contractions Baseline RAte Variability Accelerations Decelerations Overall impression
What management is considered following abnormal CTG?
Change maternal positon IV fluids Stop syntocinon Scalp stimulation Consider Tocolysis with Terbutaline Maternal assessment Consider foetal blood sampling
What is considered normal and abnormal for scalp pH, and what is the action taken for this?
Normal - > 7.25 - no action
Borderline 7.20-7.25 - repeat 30 mins
Abnormal - < 7.2 - delivery
What are the standard indications for an operative vaginal delivery?
Failure to progress in stage 2 for:
Prims - 2 hours no epidural, 3 hours with
Multips - 1 hour no epidural, 2 hours with
What are special indications for operative vaginal delivery?
Maternal cardiac disease
Severe PET/eclampsia
Intrapartum haemorrhage
Umbilical cord prolapse during stage 2
How is the most appropriate instrument chosen for operative vaginal delivery?
Agpar score
What are the benefits and risks to Ventouse?
Benefits - reduced anaesthesia, vaginal traum and perineal pain
Increased - failure, cephalohaematoma, retinal haemorrhage and maternal worry
What are the indications for caesarean section?
Previous CS Foetal distress Failure to progress Breech presentation Maternal request
