Abnormal Labour Flashcards
What is malpresentation?
Presentation of the foetus other than the vertex
What is malposition? Give some examples.
The vertex has presented first but not in the right direction e.g. OP or OT
What is the management of each of the following malpositions: a) OP? b) OT?
a) can be delivered vaginally b) C-section required
Define preterm and post-term delivery?
Pre-term = < 37 weeks, post-term = > 42 weeks
What is the risk of having a post-term baby?
After term, the rates of stillbirth increase exponentially
What is the vertex bound by?
The anterior and posterior fontanelles and the 2 parietal eminences
What is used to assess a baby’s position during delivery?
Feeling the fontanelles on vaginal examination
How do you differentiate between the anterior and posterior fontanelles on palpation?
Anterior fontanelle is diamond shaped and the posterior fontanelle is triangle shaped
There are higher chances of having a normal vaginal delivery in who?
Women who have already had a normal vaginal delivery
Forceps and C-section delivery are more likely in who?
Women who have never had a baby before
What is the management of a cord prolapse?
Emergency C-section within 30 minutes
Malpresentation is only a problem when?
When the woman is in active labour, especially if the membranes have ruptured
What is the commonest type of malpresentation? What part is presenting first?
Breech - the baby’s bottom is the presenting part
Aside from a breech, what are some other type of malpresentation? What part is presenting first?
Transverse (shoulder presenting part), mentoanterior/mentoposterior (chin presenting part) or brow (face presenting first)
What is the management for each of the following presentations: a) mentoanterior? b) mentoposterior?
a) can be delivered vaginally b) C-section
If a woman is known to be carrying a breech baby they should be counselled about this. What should you explain to them?
That a breech presentation can result in foetal parts passing through an undilated cervix, which can cause larger structures such as the head to get stuck which can cause hypoxia
Describe the management of breech presentations?
Frank or complete breech babies can still be delivered vaginally, though most mothers opt for an elective C-section. A footling breech must be delivered by C-section (because there is nothing pressing on the cervix causing it to dilate)
Can an a) transverse presentation and b) brow presentation be delivered?
a) no b) no
If a malpresentation is suspected, how should the diagnosis be confirmed?
US
Describe the process of picking regional anaesthesia for delivery?
Epidural is usually used, it is good since it can last through all of labour as it can be topped up. If under time pressure, a spinal anaesthetic takes 15 minutes and a GA even less.
In an epidural anaesthetic, what is injected?
A local anaesthetic and an opioid
The first dose of epidural is essentially a test run to ensure what?
Intrathecal injection has not occurred
What are some complications of epidural anaesthetic?
Hypotension, dural puncture, headache, atonic bladder
What are downsides to epidural use in labour?
Can inhibit and prolong stage 2 of labour, requires monitoring and IV access, reduces mobility
What are some complications of failure to progress?
Sepsis (maternal and neonatal), uterine rupture, obstructed AKI, PPH, foetal asphyxia
How is the progress of labour assessed?
Cervical dilatation, descent of presenting part, signs of obstruction
What are some signs of obstruction?
Moulding, caput, anuria, haematuria, vulval oedema
In a low risk delivery, when should vaginal examination be done?
Only when you need to or if there are signs of foetal distress
In a high risk delivery, when should vaginal examination be done?
Every 4 hours
In the first stage of labour, when do you suspect delay?
If there has been < 2cm dilatation in 4 hours in both nulliparous and parous women. Also if there is slowing in progress in a parous woman.
In the second stage of labour, when do you suspect delay?
Nulliparous: failure to deliver within 2 hours of active pushing / parous: failure to deliver within 1 hour of active pushing (add 1 hour to both if regional anaesthesia)
What is the main cause of failure to progress due to power?
Inadequate contractions - frequency or strength
What amount of contractions in 10 minutes is a) normal? b) hyperstimulation? c) inadequate?
a) 3-5 b) > 5 c) < 3
In failure to progress, how is the power assessed?
By how much the uterine contractions are affecting the dilatation of the cervix
What is the main cause of failure to progress due to passages? What are some causes for this?
Mismatch in the size between the pelvis and foetus / short stature or pelvic trauma
What are some causes of failure to progress due to passenger?
Foetal size, presentation or position
What is the first thing to do to manage failure to progress if it has not happened already?
Artificial rupture of membranes
How is failure to progress managed in the first stage of labour?
IV syntocinon is given and vaginal exam done 4 hours later. If dilatation has not increased by at least 2cm then a C-section is indicated.
How is failure to progress managed in the second stage of labour?
If the station is 0 or more then aim for operative vaginal delivery, if not then C-section
Foetal distress is suspected based on what things?
Changes in heart rate, passage of meconium and decreased movements
How is foetal heart rate monitoring in a) low risk pregnancies? b) high risk pregnancies?
a) Intermittent Doppler auscultation b) continuous CTG monitoring
During the active phase of the 1st stage of labour, how often is Doppler auscultation of the foetal heart performed?
During and for 1 minute after every contraction or minimum every 15 minutes
During the 2nd stage of labour, how often is Doppler auscultation of the foetal heart performed?
During and for 1 minute after every contraction or minimum every 5 minutes
How are the results of intermittent Doppler auscultation of the foetal heart rate recorded?
Recorded as a single, average rate on the partogram
During labour, the colour of the amniotic fluid is measured and recorded where?
On the partogram
What colour should the amniotic fluid be?
Clear
If the amniotic fluid is red, what does this suggest?
Presence of blood or clots e.g. antepartum haemorrhage
If the amniotic fluid is brown/green, what does this suggest?
Meconium - this can be normal in late deliveries but can be a sign of foetal distress
When you are auscultating the foetal heart after a contraction, what are you listening for?
The presence of late decelerations which are a sign of foetal hypoxia
What are some acute aetiologies of foetal distress?
Antepartum haemorrhage (many causes), cord prolapse, uterine hyperstimulation, regional anaesthesia
What are some chronic aetiologies of foetal distress?
Placental insufficiency or foetal anaemia
What are some simple measures of management for foetal distress?
Change maternal position, IV fluids, stop syntocinon/consider tocolysis
If tocolysis is to be given for foetal distress, what is used?
Terbutaline 250mcg SC
When a CTG is pathological and delivery is not imminent, what is the best investigation to do? For this to be done, the cervix must be what?
Foetal blood sampling / 4cm+ dilated
What are some last line management options for foetal distress?
Operative vaginal delivery or C-section
If a foetal pH comes back as >7.25, what does this mean and what is the management?
Normal - no management
If a foetal pH comes back as 7.2-7.25, what does this mean and what is the management?
Borderline, repeat test in 30 mins if no improvement
If a foetal pH comes back as <7.2, what does this mean and what is the management?
Abnormal, deliver
What are the main indications for operative vaginal delivery?
Failure to progress in the 2nd stage, contraindications to a prolonged 2nd stage (e.g. cardiac disease), maternal fatigue, suspected foetal compromise
What are the two main options for operative vaginal delivery?
Ventouse or forceps
What are the disadvantages to using a ventouse for operative vaginal delivery?
Increased failure rates, cephalohaematoma, retinal haemorrhage
What are the advantages to using a ventouse for operative vaginal delivery?
Less anaesthesia needed, less perineal trauma
With a forceps delivery, the baby is more likely to come out - why is a ventouse still considered over this?
Because forceps increase the diameter of the head and therefore are more painful
What procedure is done in around 90% of operative vaginal deliveries?
Episiotomy
PPH which occurs following an operative vaginal delivery is usually due to what?
Uterine atony or perineal trauma
What harm may a forceps delivery cause to the baby?
May cause temporary marks on the baby’s face and can rarely cause a CNVII palsy
What harm may a ventouse delivery cause to the baby?
Cause achignon - a swelling on the baby’s head which reduces in 48h
What are the indications for emergency C-section?
Foetal compromise, cord prolapse, failure to progress despite use of syntocinon
Why is there are increased risk of C-section babies having to go to the NICU?
They have breathing problems as the fluid is not expelled from the lungs as it would be in a vaginal delivery (transient tachypnoea of the newborn)
The more C-sections a woman has, the risk of what increases in future pregnancies?
Placental problems
Describe what happens in shoulder dystocia and how it should be managed?
The anterior shoulder gets stuck behind the symphysis pubis which causes hypoxia - you have 7 minutes to deliver the baby
From 20 weeks, what effect can the gravid uterus have on the circulation in the supine position?
Compresses the IVC and aorta - reduces venous return causing supine hypotension
Supine hypotension can precipitate what? How is this solved?
Maternal collapse / turning the woman to the left lateral position
What must you do before performing CPR on a woman who is pregnant?
Displace the uterus or sit them up
If there is no response to correctly performed CPR on a pregnant woman within 4 minutes of collapse, what is the management?
Delivery, to assist maternal resuscitation
