What is labour?
Process of uterine contractions + cervical dilatation that enables the uterus to deliver the viable fetus (>22wks), placenta + membranes
When is labour diagnosed?
When there are regular and increasing uterine contractions that bring about progressive cervical effacement and/or dilatation
When is the first stage of labour?
- period between onset of regular painful uterine contractions to full cervical dilatation
- this is difficult to quantify + scientific studies are based on observed first stage of labour
- split into latent and active phases
When is the second stage of labour?
- from full cervical dilatation to delivery of the fetus
- usually one hour in the nulliparous + half an hour in the multiparous woman
When is the third stage of labour?
- from delivery of the fetus to delivery of the placenta + membranes
- usually <15 mins w/ active management of the third stage of labour
The first stage of labour is split into the latent and active phase. What is the latent phase and how long can it take?
- duration for the cervix to become effaced (from 3cm long to <0.5cm) - “cervical thinning” / effacement
- with regular uterine contractions it could take 6-8 hrs in a nullipara, and 4-6hrs in a multipara
What is the active phase?
- duration for the cervix to dilate from 3 to 10cm (fully dilated)
- rate of cervical dilatation is on the avg about 1cm/hr
What are partograms? What events are recorded?
- partogram is a graphic representation of the progress of labour
- events recorded are:
- descent of head
- contraction frequency + duration
- FHR + colour/quantity of liquor
- caput + moulding of the head
- maternal parameters of pulse
- BP, temp + urine output/analysis
What are alert and action lines?
- alert line - a line drawn at a rate of 1cm/hr from admission cervical dilatation in the active phase
- action line - a line drawn 2 or 3cm to right + parallel to alert line (a labout stencil can be used to draw this line)
labour progress to the right of the action line is deemed to be slow needing some intervention
What are the 3 causes of slow labour?
- passage - inadequate pelvis (short stature, prev injury to pelvis, soft/bony tumour)
- passenger - fetus may be large or may be present w/ sub-optimal diameter (as with malposition or brow presentation)
- power - inadequate uterine contractions (commonest cause)
What needs to be carried out for admission into labour?
- assessment - low or high risk - team management + apportionment of care
- definitive diagnosis of labour - may be difficult + may need a period of observation
- adhere to agreed action plan
- consult when required - lines of communication + command must be clear
How should you manage the slow latent phase?
- reassurance - one-to-one support
- nutrition, hydration + pain relief
- ambulation
- appropriate fetal + maternal surveillance
- allow labour to progress naturally (bc of difficulty in making a definitive diagnosis of labour)
- active management if obstetric or medical complication of pregnancy or fetal compromise is suspected
How should you manage the slow active phase?
- reassurance - one-to-one support
- hydration
- adequate pain relief
- artificial rupture of membranes
- judicious use of oxytocin
- fetal surveillance
- monitoring progress of labour and maternal condition
Outline the use of oxytocin
- start w/ low dose of 2-4 mu/min and increase by 2-4 mu
- most labours respond well with 8-12 mu/min
- escalation of dose every 30 min is adequate + reduces hyperstimulation
- target uterine activity - 4-5 contractions every 10 min, each lasting for >40 seconds
- total duration of oxytocin - unlikely to benefit if unsatisfactory progress with 6-8hrs of oxytocin infusion
What is the target uterine contraction activity?
4-5 contractions every 10 mins, each lasting >40 seconds
What are complications of slow labour?
- maternal dehydration/exhaustion
- maternal + fetal infection
- fetal distress
- operative delivery
- uterine rupture
- postpartum haemorrhage
- inc maternal + fetal morbidity
- vesicovaginal fistula
Do use of IUP catheters for oxytocin infusion improve outcome? What are cautions with oxytocin infusion?
- no, do not improve outcome
- beware of hyperstimulation + iatrogenic fetal distress
- uterine rupture is rare but care exercised in multiparae
- ‘ADH’ effect + water intoxication w/ high dose + prolongued use
What is dystocia?
- Shoulder dystocia is a specific case of obstructed labour whereby after the delivery of the head, the anterior shoulder of the infant cannot pass below, or requires significant manipulation to pass below, the pubic symphysis. It is diagnosed when the shoulders fail to deliver shortly after the fetal head.
Cephalopelvic disproportion is a retrospective diagnosis. What is meant by this?
CPD can rarely be diagnosed before labor begins if the baby is thought to be large or the mother’s pelvis is known to be small.
So only diagnosed after/during labour - can’t be predicted really
What are conclusions to draw in terms of management of labour?
- know your protocols
- provide support, pain relief + hydration
- communicate fully all actions
- emotional support is essential
- if normal-midwifery led care
- be prepared for any emergency
- consult when required
What are the two phases of the second stage of labour?
- passive (pelvic)
- active (perineal)
What factors can account for a prolonged second stage of labour?
being either…
- nullipara (longer) or multipara
- epidural (longer) vs no epidural
- active pushing vs no-active pushing
- pelvic phase vs perineal phase
- maternal exhaustion vs maternal distress
- failure to descend/rotate
What are the prerequisites for assisted vaginal delivery?
- head 0/5’th or 1/5’th palpable
- not a large baby
- cervix fully dilated
- membranes ruptured
- not excessive caput/moulding
- satisfactory fetal condition
- empty bladder
- suitable presentation/position
- descent w contraction + bearing down effort
What is assisted vaginal delivery?
When your healthcare practitioner uses either a vacuum device or forceps to help your baby out of the birth canal. Your practitioner may recommend this if you’ve been pushing for a long time and you’re completely worn out, or if your baby’s nearly out but his heart rate is “nonreassuring.”
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Intro to Reproduction and Sexual Differentiation28
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Hypothalamic / pituitary / gonadal axis27
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Puberty and Its Disorders41
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Folliculogenesis22
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Social construction of gender14
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The Menstrual Cycle39
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Uterus, uterine tubes and cervix28
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Contraception40
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Psychosexual development43
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Pharmacology of androgens and anti-androgens41
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Spermatogenesis24
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Fertilisation and the Luteal Phase21
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Maternal changes in pregnancy26
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Implantation, placentation and hormone changes in pregnancy25
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Labour29
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Complications of Pregnancy31
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Pharmacology of the Uterus36
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Menopause24
