Mx of Labour and Delivery Flashcards
Signs that labour is on the way (4)?
Braxton Hicks contractions become > freq
Pressing part becomes
Uterine fundus descends
P in pelvis increases
Diagnosis of labour
Painful uterine contractions + dilation + effacement of cervix
Stage 1 labour
Cervix opens –> full dilation (10cm)
Stage 2 labour
Cervical dilation –> delivery
Stage 3 labour
Delivery foetus –> delivery placenta
What are the 3 factors determining the progression of labour?
Powers
Passage
Passenger
What is ‘Power’
Degree of force expelling foetus
What is ‘Passage’
Dimension of pelvic + resistance of soft tissue
What is ‘Passenger’
Diameter of foetal head
What is effacement
The cervix being pulled up
Dimensions of pelvic inlet
TD - 13cm > AP - 11cm
Dimensions of pelvic mid-cavity
TD = AP
Dimensions of pelvic outlet
AP - 12.5 > TD 11cm
How is the level of descent measured?
From Ischial spines
What 3 things does cervical dilation depend on?
Contractions
P of foetal head
Ability to soften
Name of anterior fontanelle
Bregma
Name of posterior fontanelle
Occiput
what is between the bregma and occiput?
Vertex
What is attitude
Degree of flexion of head/neck
What is the ideal attitude?
Vertex presentation (maximal flexion) Presenting diameter - 9.5cm
What has a diameter of 13cm
Extension 90’
Brow presentation
What has a diameter too large to deliver?
Face presentation
exxtension 120’
What is position
Degree of rotation of head on neck
What is moulding
Head is able to be squashed with bones overlapping hence decr diameter
What occurs in the initiation of labour
Involuntary contraction of uterine SM
Incr PG –> Decr cervical resistance + oxytocin released
Latent phase stage 1 labour
Cervix dilates slowly for first 4cm. This can take several hrs
Active phase stage 1 labour
Rate of 1cm/hr nulliparous
Rate 2cm/hr multiparous
What is the longest stage 1 of labour should take?
16hrs
4 stages of stage 2 of labour
Descent –> flexion –> rotation –> extension
Passage stage 2 labour
Full dilation - head reaches pelvic floor
Lasts mins
Active stage 2 labour
Mother is pushing
Pressure of head on pelvic flr forces women to bear down
How long does active stage 2 take nulliparous woman
40 mins
How long does active stage 2 take multiparous women
20 mins
After reaching the perineum, how does the head come out of the pelvis
It extends
After the head extends, what comes next
Head rotates back to transverse position + descend w/ next contraction
How long does stage 3 labour normally take?
15 mins
What is the normal blood loss in the 3rd stage of labour?
500ml
Obs - what should be checked every 15 mins
Foetal HR
Obs - what should be checked every 30 mins
Uterine contractions
Obs - what should be checked every 1hr
Maternal HR
Obs - what should be checked every 4hours
VE
Maternal BP + temp
Urine dip - protein + ketones
Which positions are good for delivery? (3)
Squatting
Kneeling
L lateral position
Why should women in labour not lie in the supine position?
Aortocaval compression –> Incr CO + Decr BP
Mx pyrexia in labour
Take cultures from - vagina, urine, blood
Give - paracetamol, IV ABx, CTG
How anxiety and fear affect labour
Adrenaline secreted
Inhibition of uternie contraction
What is the most common cause of slow progress through labour?
Inefficient uterine action
Who is more likely to have inefficient uterine action
Nulliparous women
IOL/Epidural
Mx Inefficient uterine action
Continuous support - reduce anxiety
Encourage mobility
Augmentation of labour –> amniotomy + oxytocin
CSC if not by 12-16hrs
Affect of hyperactive uterine action (3)
Decr placental blood flw
Rapid labour
Placental abruption
Tx hyperactive uterine action
If no abruption - tocolysis
CSC if foetal distress
Augmentation
Artificial strengthening of contractions in established labour
Induction
Artificial initiation of labour
Effect of OP persentation on labour
Incr time + Pain
Backache + early desire to push
Mx of OT presentation
Rotate with traction using ventouse
What is Brow presentation?
Extension of foetal head –> large presenting diameter –> won’t deliver vaginally
What can you feel on VE in Brow presentation?
Anterior fontanelle supraoribital ridges + noses palpable
Mx Brow presentation
CSC
What is face presentation?
Complete extension of foetal head hence face presents
What can you feel on VE in face presentation?
Mouth, nose + eyes palpable
Mx face presentation
Can deliver vaginally
When would you need a CSC for face presentation?
If chin = posterior
Who is cephalo-pelvic disproportion more common for? (2)
Large baby
Short woman
Severe causes of damage to foetus during labour (5)
Hypoxia Infection/inflammation in labour Meconium aspiration Trauma Foetal blood loss
RF/causes of foetal damage during labour (8)
Long labour >1hr pushing time Abruption Hypertonic uterine state Use of oxytocin/epidural Cord prolapse Maternal hypotension Pre-eclampsia
ways of Diagnosis of foetal distress in labour (4)
Colour of meconium
FHR
CTG
FBS
How often is FHR ausculatated in 1st stage labour
Every 15mins
How often is FHR ausculatated in 2nd stage labour
Every 5 mins
How is a FBS taken?
Amnioscope inserted vaginally –> cervix –> babies scalp –> collect blood
Mx of foetal distress in labour
In utero resus = L-lateral position O2 + IV fl Stop oxytocin Can stop contractions w/ B2 agonist e.g. terbutaline VE - exclude prolapse
What is the rate of O2 consumption of a foetus compared to an adult?
2x
How long can a foetus be supported by its O2 reserves?
1-2mins
What are the 5 main groups of reasons a fetus’s O2 can be impaired?
Placental conditions Maternal conditions Fetal condition Uterine condition Umbilical cord condition
3 examples of placental conditions affecting foetal O2 supply
Infarction
Abruption
Post-mature placenta
6 examples of maternal conditions affecting foetal O2 supply
HTN HoTN Severe anaemia Cardiac disease Seizures Pulmonary disease
3 exams of foetal conditions that affect foetal O2 supply
Anaemia
Infection
Twin-twin transfusion
2 examples of uterine conditions affecting foetal O2 supply
Tetanic contraction
Hyperstimulation
5 examples of umbilical cord condition that affect foetal O2 supply
One aa Haematoma Short cord True knot Nuchal cord prolapse
Which develops first, the SNS or paraSNS
SNS
Indications CTG (17)
IOL >42weeks Previous LSCS Maternal cardiac problems Pre-eclampsia or HTN Prolonged rupture membranes >24hrs <37weeks Small for gestation age Oligohydramnios Abnormal umbilical aa Doppler Multiple pregnancy Meconium stained liquor Abnorm lie - Breech Oxytocin augmentation Epidural anaesthesia Pyrexia Abnormality heard on ausc
What is the false +ve rate of CTG for fetal hypoxia?
50%
DR C BRAVADO
DR - determine risk C - contractions BRA - baseline HR V - variability A - accelerations D - decelerations
What should the Baseline heart rate of a fetus be?
100-160
Causes of sustained tachyC (4)
Prematurity
Fetal hypxia
Maternal pyrexia
Use of exogenous B-sympathomimetics
Causes of baseline bradycardiac (3)
Fetal acidosis
HoTN
Maternal sedation
What should variability be between?
5-25
What is variability
The interplay between CNX (PNS) and SNS
Causes of reduced variability (6)
Baby sleeping (40mins) Fetal hypoxia Malformation Mg Prematurity < 2w Dx - pethidine, morphine
What is an acceleration
Upward spike of >15bpm for >15s
What does an acceleration mean
Baby is moving
What is a deceleration
Downward spike of >15bpm for >15s
What are early decelerations
Baroceptor decelerations
Mimic shape + timing of contraction by foetal head compression
What are late decelerations
Chemoreceptor decelerations
Signs of acidosis
What is an atypical deceleration
Loss of shouldering, last >60s, >60bpm, may be slow to recover by a W shape + lose variability with the decelerations
What may atypical decelerations be a sign of?
Fetal hypoxia
3 classifications of CTG
Reassuring
Non-reassuring
Abnormal
How to improve a CTG (3)
L Lateral position
IV fl
Reduce/stop oxytocin if contraction >5:10 or bradyC
WHy is hyperstimulation bad (2)
Increases resting tone of uterus
O2 in retroplacental blood pool isn’t properly replenished betw contractions
Mx hyperstimulation
Terbutaline 250mg
