Intrapartum Care: Normal Labour Flashcards
What 2 drugs can be used to induce labour
Prostaglandins
Oxytocin
What should be checked 30m before and after giving prostaglandins
CTG
After how long can a second dose of prostaglandins be given
6h
Can oxytocin be started with prostaglandins and why
No. Wait 6h - otherwise causes hyperstimulation
Explain giving oxytocin to induce labour
Oxytocin should be started at lowest dose and gradually increases to given 3-4 contractions in 10 minutes.
What should a patient be on if oxytocin
Continuous CTG monitoring
What should be checked if oxytocin is used for more than 12h and why
U+E. Oxytocin has ADH features and hence can cause dilutional hyponatraemia
Define failure to progress
<2cm dilation in 4h first stage labour
What is dysfunctional labour
Individual has poor labour from offset
Define secondary arrest
individual has initial good progress which then ceases
Define labour
regular, increasing and efficient uterine contractions
What proceeds labour
show
What is a show
cervical mucus as membranes rip from the OS
How is labour divided
First stage
Second stage
Third stage
How long does the first stage take in a primip
8-18h
How long does the first stage take in a multip
5-12h
What does the first stage of labour involve
Dilation of cervix from 0-10cm
How can the first-stage of labour be divided
- Latent phase
2. Established phase
What are 2 features of latent phase of labour
- Irregular contractions
- Cervix dilates to 4cm
What is the established phase of labour
- Cervix dilates 4-10cm
- Effacement
- Regular contractions
What rate does cervix dilate in established phase
<0.5cm/hour
What are 3 clinical features of stage I labour
Bloody Show
Cervical dilation
SROM
What is second stage labour
From cervical dilation (10cm) to delivery
How long is second stage in nulliparous
3h
If delivery is not imminent in nulliparous women in what time frame should an obstetrician be called
2h
How long is second stage in multiparous and when should obstetrician be called
2h. Call if not imminent in 1h
How can second stage be divided
Passive
Active
What is passive stage of labour
Cervix dilated to 10cm
Mother has no urge to push
Baby remains high in pelvic
What may increase duration passive stage of labour
Epidural
How long may epidural increase passive stage by
1-2h
What is the active phase of labour
Maternal urge to push
What is a mnemonic to remember stages of labour (1+2)
LEPA
What are the sub categories of stage 1 and 2 labour
Latent phase
Established phase
Passive stage
Active stage
What is stage 3 labour
From delivery of foetus to delivery of placenta
How long does stage 3 labour usually take
1h
What happens to the uterus post-delivery
returns to pre-24w size
If the uterus does not return to normal size what may it indicate
choriocarcinoma
Explain separation of placenta
Contraction uterus impedes venous return causing congestion of blood;
Retroplacental clot causes placenta to seperate
What are alvarez waves
low intensity, high-frequency contractions that occur after 20W
What are braxton hicks contractions
high intensity contractions that happen after 20W - usually lasting 1-minute
In what time frame may false labour occur
3-4W pre-term
What is false labour
Irregular contractions of moderate intensity - not increasing in frequency or intensity. No cervical changes
What is used to manage false labour
Analgesia
What time frame does pre-labour occur
3-4d before term
What is pre-labour
irregular contractions of high-intensity occurring every 5-10m
What is the role of pre-labour
position head
What is the rate of contractions in labour
3-4 in 10 minutes
What is measured every 15m during first stage labour
Foetal HR, unless on CTG
What is check every 30m in first stage labour
Contractions: strength and frequency
What is the ideal rate of contractions
3-4 in 10m
What is checked every 60m in first stage labour
Maternal HR
What is checked every 4h in labour first stage
Maternal BP and T
What is checked every 1h in second-stage labour
Maternal pulse and BP
What is checked every 4h in second-stage labour
Maternal Temp
What is checked every 30m in second-stage labour
Contractions
Why may pressure be applied over perineum in second stage
To prevent precipitated delivery= childbirth after rapid labour, which leads to expulsion of the infant and risk intracranial haemorrhage
How long is cord clamping delayed
1m
If a premature baby how long is cord clamping delayed
3m
What are the signs of third stage
Uterus contracts
Cord lengthening
What is used to manage third stage labour
Syntometrine
What is syntometrine
Ergometrine and oxytocin
Why is syntrometrine given
Reduces third stage to 5m
Reduces risk PPH
What is problem with syntometrine
can precipitate MIs
When is syntrometrine CI
pre-eclampsia, severe HTN
If BP has not been measured during pregnancy what is give as alternative to synto
Oxytocin
What should be used to monitor parameters of labour in all women
Partogram
What are the two lines on a partogram
Action and alert lines
What is normal labour
Labour is to the left of action and alert lines
What is the alert line
line drawn at 1cm/h from admission cervical dilation
What is the action line
line 2-3cm to right of alert line
What are 3 non-pharmacological methods of analgesia during labour
- Education about labour
- TENs
- Water birth
When is water birth not possible
If high-risk birth on CTG monitoring
What are 3 pharmacological methods to reduce pain during labour
- Narcotics
- Entonox
- Local anaesthetic
What is entonox
Nitric oxide in oxygen
What are 3 side effects of entonox
Lightheadedness
Nausea
Vomiting
When is entonox contraindicated
Pneumothorax
What narcotic can be used during labour
Pethidine
What are the risks of pethidine to mother
Drowsiness
What are risks of pethidine to baby
Respiratory depression
What is the problem with birth plans and narcotics
Unable to enter birthing pool for 2h
What form of patient controlled analgesia can be used in labour
Remifentanil
When is local anaesthetic used
Used for episiotomy or suturing tears
What is a pudendal nerve block
S2-S4 nerve block
When is pudendal nerve block used
Perineal infiltration for Instrumental delivery
What nerve roots does an epidural block
T10-S5
What is the advantage of epidural
Cannula remains in epidural space so can be regularly topped up every 2h
Why is epidural useful in pre-eclampsia
Causes maternal hypotension
What needs to be checked before giving an epidural
Platelets.
Need to be >75
What space is an epidural inserted
L3-L4
What monitoring should happen in epidural
Maternal BP
What may happen to foetus after inserting epidural and why
Bradycardia - due to maternal hypotension
How long after LMWH can an epidural be put in
12h
How long should you wait following an epidural to administer LMWH
4h
What is spinal anaesthesia used for
LSCS
Define engagement
When the largest part of the babies head passes through pelvic inlet
What is crowning
When babies head appears at the vagina
How does the babies head enter the pelvis
Occipito-lateral
What position is the babies head when it delivers
Occipito-anterior
What is checked each vaginal exam during labour
Descent and engagement
How is descent measured
By 5ths across pelvic brim
What is 5/5
Whole head at pelvic inlet
What is 4/5
Small part past pelvic brim - can be lifted into pelvis with a deep grip
What is 3/5
Head cannot be lifted out of the pelvis
What is 2/5
Majority head below pelvic brim
What is 1/5
Only tip of the head is below the pelvic brim
What does CTG measure
Aims to determine foetal distress by measuring acceleration/decceleration and pressure in the uterus
What is the mnemonic to remember NICE indications for continuous CTG monitoring
THOMB
What are the indications for continuous CTG monitoring
T > 38 HTN: 160/110 Oxytocin Meconium severe Bleeding PV
What is the normal foetal HR
110-160
Define foetal tachycardia
HR >110 for >10 minutes
What is mild foetal tachycardia
160-180
What is severe foetal tachycardia
> 180
What are 7 causes of foetal tachycardia
- Stress
- Maternal Fever
- Chorioamnionitis
- Medications
- Hypoxia
- Hypotension
What is mild foetal bradycardia
HR <120 for >3 minutes
What is severe foetal bradycardia
HR < 100 for >3 minutes
What can cause foetal bradycardia
Heart defects
Supine hypotensive syndrome
CNS anomalies
Hypoxia
What is acceleration
Temporary increase in HR by >15bpm for less than 10-minutes
What causes acceleration
Baby moving
What does absence of accelerations indicate
Sedatives
Sleeping
Hypoxic
What is an early deceleration
Decrease in foetal HR of >15bpm for <3m
Describe appearance of early deccelerations
The beginning and end of the deceleration coincides with uterine contraction. Reaches peak when uterine contraction reaches its maximum
What is the nadir
Peak of deceleration
What is the onset to nadir in early contractions
> 30s
What causes early decelerations
Uterus contraction causes head compression which increases vagal tone
What is a late deceleration
Decrease in FHR that does not coincide with uterine contraction
Explain nadir in late deceleration
> 30s
What causes late decelerations
Umbilical cord insufficiency cause foetal hypoxia and acidosis
How are late decelerations usually managed
Urgent C-Section
What are variable decelerations
Abrupt onset to nadir, leasts at least 15s
What causes variable decelerations
Umbilical cord compression
Umbilical cord prolapse
What is a prolonged deceleration
Decrease in FHR of more than 15bpm for 2-10m
What do prolonged decelerations indicate
Foetal hypoxia
What can prolonged decelerations lead to
Hypoxic-Ischaemic encephalopathy
Cerebral palsy
What causes prolonged decelerations
Uterine contraction
IVC syndrome
Epidurals
Rapid drop in maternal BP
What defines a short episode of decreased variability
Decrease in variability for less than 30-minutes
What is the most common cause for short-episodes of decreased variability
Foetus sleeping
When does decreased variability become concerning
More than 40 minutes
What is a mnemonic to remember presentation and cause of CTG traces
VEAL CHOP
What does VEAL CHOP stand for
Variable decelerations
= Cord compression
Early decelerations
= Head compression
Accelerations
= Ok
Late decelerations
= Placental insufficiency
What is a sinusoidal pattern on CTG
- Smooth wave-like appearance.
- Cycles every 2-5 minutes.
- Baseline HR at 120-160
- No beat to beat variability
What does sinusoidal pattern on CTG mean
Maternal haemorrhage
Foetal anaemia
Foetal hypoxia
If a foetus has suspected hypoxia what is next-line investigation
Foetal scalp blood sampling
What determines whether a baby is delivered on foetal scalp blood sample
pH
If pH is less than 7.2 what should be done
Immediate delivery
If pH is 7.21-7.24 what should be done
Repeat in 30m
If pH is more than 7.25 what should be done
Repeat in 1h