Labour - Management Flashcards
How should blood pressure and temperature of a woman in labour be managed?
temperature and BP monitored every 4 hours - pulse every hour (1st stage) and then every 15 mins (2nd stage) and contraction frequency should be measured every 30 mins
In what position do most ladies deliver in?
Semi-recumbent position - e.g. squatting, kneeling, or left-lateral position
supine is avoided as can lead to compression of main blood vessels leading to reduced CO, hypotension and foetal distress
Can women eat during labour?
Yes, unless high risk, as may need general anaesthetic
What is pyrexia in labour associated with?
what is the management of pyrexia in labour?
Increased risk of neonatal illness - more common with epidural and prolonged labour. Paracetamol is administered, and IV antibiotics and CTG monitoring are warranted if the fever reaches 38 degrees.
What is the effect of retention of urine?
Irreversible damage fo the detrusor muscle - frequent micturition is encouraged in labour
catheterisation is required if an epidural is in situ.
What is progress in labour dependent?
Power (uterine contractions)
Passenger (size, presentation and position of the baby)
Passage (the shape and size of the pelvis and soft tissues)
What is the minimum rate of dilation after the latent phase?
1cm/hr
What is the most common cause of slow progression of labour?
inefficient uterine action - common in nulliparous women and induced labour
Persistently slow progress is treated with augmentation, initially with amniotomy and then oxytocin
In what circumstances does hyperactive uterine action occur?
Excessively strong, frequent or prolonged contractions
What are the complications of hyperactive uterine action?
foetal distress occurs as placental blood flow is diminished and labour may be very rapid
associated with placental abruption, too much oxytocin or a side effect of PG administered to induce labour.
What is the treatment of hyperactive uterine action?
if no abruption - can be treated with a tocolytic (salbutamol IV) - but C-section is often indicated because of foetal distress
What is slow progress in nulliparous women usually due to?
Inefficient uterine action
How can slow progress in nulliparous women be managed?
Amniotomy, also known as artificial rupture of membranes (ARM) for women with intact membranes
Oxytocin infusion
Instrumental delivery
Caesarean section
Oxytocin - first-line to stimulate uterine contractions during labour. It is started at a low rate and titrated up at intervals of at least 30 minutes as required. The aim is for 4 – 5 contractions per 10 minutes.
What is the management for poor descent?
oxytocin induction - pushing not encouraged until the woman feels the urge - epidural diminishes this urge
If active 2nd stage lasts longer than 1-2 hours, what is the management?
Instrumental delivery - maternal exhaustion, foetal hypoxia and maternal trauma
What needs to be excluded in augmentation of labour in a multiparous woman?
Malpresentation
In what ways can the foetus contribute to poor progress in labour?
OP position
OT position
Brow presentation
Face presentation
What are the indications for instrumental delivery?
Failure to progress
Fetal distress
Maternal exhaustion
Control of the head in various fetal positions
What positions of the head make labour more difficult?
OA preferred
OP or OT make difficult
What is the management of OT position?
OP?
rotation with traction is required for delivery to occur and is achieved with the ventouse
OP: Keilland’s forceps
What is the effect of Brow presentation?
extension of the foetal head on the neck results in a large diameter that will not normally delivery vaginally.
anterior fontanelle, supraorbital rides and nose are palpable vaginally
What is the management of Brow presentation?
C-section is required
What is the effect of face presentation?
Complete extension of the head resulting in the face being the presenting part.
Foetal compromise in labour is more common. Presenting diameter is 9.5cm allowing vaginal delivery in most cases, as long as the chin is anterior.
Delivery is completed by flexion over the perineum. If the chin is posterior, then a C-section is indicated
What is cephalo-pelvic disproportion?
When the pelvis is too small to allow passage of the head, but can almost ever be diagnosed with certainty.
Depends on foetal and pelvic size and usually diagnosed retrospectively.
Defined as: inability to delivery a particular foetus despite presence of adequate uterine activity and absence of a malposition or presentation
What increases the chance of cephalo-pelvic disproportion?
Large baby
very short woman
where the head in a nulliparous woman remains high at term
What pelvic abnormalities prevent engagement and descent of the head?
Pelvic mass
ovarian tumour or uterine fibroid
C-section indicated
What are the causes of permanent foetal damage?
Foetal hypoxia - commonly described as distress
Infection/inflammation in labour - e.g. GBS
Meconium aspiration leading to chemical pneumonitis
Trauma - commonly due to obstetric intervention (e.g. forceps)
Foetal blood loss
What is foetal distress?
Hypoxia that might result in foetal damage or death if not reversed or the foetus delivered urgently.
What is the threshold that indicates severe hypoxia?
Foetal scalp blood with pH of <7.2 indicated significant hypoxia.
pH <7 - neurological damage is considerably more common and even then, most babies with neurological damage had a normal pH at birth. this suggests other influences, such as IUGR or maternal fever on neonatal outcome
What can acute hypoxia in labour be due to?
Long labour Placental abruption Hypertonic uterine states Use of oxytocin Prolapse of the umbilical cord Maternal hypotension
What are the intrapartum risk factors of foetal distress?
long labour
meconium
epidurals
oxytocin
What are the antepartum risk factors of foetal distress?
Pre-eclampsia
IUGR
How is foetal distress diagnosed?
Colour of the liquor
Foetal heart auscultation
CTG
Foetal blood sampling
What is meconium?
Bowel contents of the foetus that stains the amniotic fluid
Rare in preterm foetuses, but common after 41 weeks.
Why is colour of the liquor an indication for caution?
meconium very diluted in amniotic fluid is not significant but undiluted - increase in perinatal mortality
- foetus may aspirate it - meconium aspiration syndrome
- Hypoxia more likely
How often is the heart auscultated in labour?
every 15 minutes during the first stage and every 5 minutes during the second stage using a Pinard’s stethoscope or handheld doppler.
Distressed foetus normally exhibits abnormal heart rate patterns
What does a CTG do?
CTG is used to measure the fetal heart rate and the contractions of the uterus
It is a useful way of monitoring the condition of the fetus and the activity of labour.
Two transducers are placed on the abdomen to get the CTG readout:
One above the fetal heart to monitor the fetal heartbeat
One near the fundus of the uterus to monitor the uterine contractions
The transducer above the fetal heart monitors the heartbeat using Doppler ultrasound. The transducer above the fundus uses ultrasound to assess the tension in the uterine wall, indicating uterine contraction.
How does foetal blood sampling work?
Blood taken from the scalp
if the pH is <7.2 then delivery is expedited in the fastest way possible
What are the features looked for on CTG? (5)
Contractions – the number of uterine contractions per 10 minutes
Baseline rate – the baseline fetal heart rate
Variability – how the fetal heart rate varies up and down around the baseline
Accelerations – periods where the fetal heart rate spikes
Decelerations – periods where the fetal heart rate drops
What should the baseline heart rate of the foetus be?
110-160
What are tachycardias associated with?
fever, foetal infection, potentially foetal hypoxia
A steep, sustained deterioration in rate suggests acute foetal distress
What should the baseline variability be?
> 5bpm, except during episodes of foetal sleep which usually last less than 45 minutes
(5-25)
What does prolonged reduced variability suggest?
Hypoxia
Describe how accelerations should be viewed?
Increases in the FHR with movements or contractions are reassuring
What are the types of decelerations?
What do they indicate?
The fetal heart rate drops in response to hypoxia.
Early decelerations are gradual dips and recoveries in heart rate that correspond with uterine contractions. Early decelerations are normal and not considered pathological. They are caused by the uterus compressing the head the fetus, stimulating the vagus nerve of the fetus, slowing the heart rate.
Late decelerations are gradual falls in heart rate that starts after the uterine contraction has already begun. Late decelerations are caused by hypoxia in the fetus, and are a more concerning finding. They may be caused by excessive uterine contractions, maternal hypotension or maternal hypoxia.
Variable decelerations are abrupt decelerations that may be unrelated to uterine contractions. There is a fall of more than 15 bpm from the baseline. Variable decelerations often indicate intermittent compression of the umbilical cord, causing fetal hypoxia.
Prolonged decelerations last between 2 and 10 minutes with a drop of more than 15 bpm from baseline. This often indicates compression of the umbilical cord, causing fetal hypoxia. These are abnormal and concerning.
What are the indications for using a CTG?
Sepsis Maternal tachycardia (> 120) Significant meconium Pre-eclampsia (particularly blood pressure > 160 / 110) Fresh antepartum haemorrhage Delay in labour Use of oxytocin Disproportionate maternal pain
What are the classifications of CTG?
What management should be undertaken?
Normal
Suspicious: a single non-reassuring feature
Pathological: two non-reassuring features or a single abnormal feature
Need for urgent intervention: acute bradycardia or prolonged deceleration of more than 3 minutes
The outcome of the CTG will guide management, such as:
Escalating to a senior midwife and obstetrician
Further assessment for possible causes, such as uterine hyperstimulation, maternal hypotension and cord prolapse
Conservative interventions such as repositioning the mother or giving IV fluids for hypotension
Fetal scalp stimulation (an acceleration in response to stimulation is a reassuring sign)
Fetal scalp blood sampling to test for fetal acidosis
Delivery of the baby (e.g. instrumental delivery or emergency caesarean section)
How many births does GBS affect?
1.7 per 1000 live births
What is a fever a strong risk factor for?
Fever = strong risk factor for seizures, foetal death and cerebral palsy, even in the absence of evidence of infection
How is Maternal fever treated?
Antibiotics and antipyretics
What is the effect of meconium aspiration?
when aspirated into the lungs, it causes severe pneumonitis
more common in the presence of foetal hypoxia, but can occur without it
How can meconium be treated if it is thick?
diluted in the uterus
How can foetal trauma be caused?
Iatrogenic
or from shoulder dystocia
What are the causes of foetal blood loss?
Vasa praevia
foeto-maternal haemorrhage or occasionally, placental abrupsion
What non-medical techniques can be employed for pain relief in labour?
Immersion in water at body temperature
TENS hypnotherapy acupuncture localised pressure on back superficial heat or cold massage aromatherapy
What inhalation agents are available?
Entonox - contains a mixture of 50% nitrous oxide and 50% oxygen. This is used during contractions for short term pain relief. The woman takes deep breaths using a mouthpiece at the start of a contraction, then stops using it as the contraction eases. It can cause lightheadedness, nausea or sleepiness.
What are the effects of entonox?
rapid onset and mild analgesia
insufficient for most mothers and can cause light-headedness, nausea and hyperventilation
What systemic opiates are available?
Pethidine and diamorphine are opioid medications, usually given by intramuscular injection. They may help with anxiety and distress. They may cause drowsiness or nausea in the mother, and can cause respiratory depression in the neonate if given too close to birth. The effect on the baby may make the first feed more difficult.
What are the effects of systemic opiates?
Analgesic effect = small and many women become sedated, confused or feel out of control
anti-emetics normally needed. can also cause respiratory depression in the newborn
What is an epidural?
An epidural involves inserting a small tube (catheter) into the epidural space in the lower back.
Local anaesthetic medications are infused through the catheter into the epidural space, where they diffuse to the surrounding tissues and through to the spinal cord, where they have an analgesic effect.
levobupivacaine or bupivacaine, usually mixed with fentanyl.
What are the effects of epidural anaesthesia?
GOOD pain relief
Adverse effects:
Headache after insertion Hypotension Motor weakness in the legs Nerve damage Prolonged second stage Increased probability of instrumental delivery
Name the three types of anaesthesia for obstetric procedures
- spinal anaesthesia
- epidural anaesthesia
- Pudendal nerve block
How is a spinal anaesthetic administered?
Local anaesthetic is injected as a single shot through the dura mater into the CSF.
This rapidly produces a short-lasting but effective local analgesia (and motor blockade) that is suitable for C-section or mid-cavity instrumental vaginal delivery
Complications include hypotension
What are the indications of epidural anaesthesia?
higher dose epidural anaesthesia can be used for both instrumental delivery and C-section
for the latter, a combination of spinal and epidural is best - allowing rapid onset due to spina and longer lasting anaesthesia with the opportunity for top ups due to the epidural
How is a pudendal nerve block done?
local anaesthetic is injected bilaterally around the pudental nerve where it passes the ischial spine.
This is suitable for low-cavity instrumental vaginal delivery
When is a woman advised to contact maternity services RE labour?
If contractions are regular, painful, lasting at least 30 seconds and occurring every 3-4 minutes, or if the membranes rupture
What is done to diagnose labour?
Presentation is checked and vaginal examination looks at cervical effacement and dilation to confirm diagnosis of labour.
The degree of descent is also assessed and the colour of leaking liquor is noted
How is it decided whether to start CTG?
Every 15 minutes, foetal heart is listened to for 1 minute following a contraction.
If the pregnancy is high risk of meconium is seen or there is maternal fever - CTG started
What position is the mother advised to avoid?
Supine
encouraged to remain mobile
What analgesia is administered in the first stage of labour?
Entonox for short term relief
Commonly - epidural.
Catheterisation will be required if an epidural is given, but otherwise not routine
How is progress over the first stage of labour monitors?
foetal heart auscultated every 15 minutes - if abnormal delivery needs to expedited, the only option is a C-section
Vaginal examination every 4 hours - dilation and descent are estimated digitally in centimetres
How can slow dilation after the latent phase be treated?
ARM - if progress continues to be slow, oxytocin is used in a nulliparous women and a multiparous woman (if malpresentation has been excluded)
What is the management if a cervix is not fully dilated by 12-16 hours?
C-section unless delivery can be anticipated in the next hour or two
When is pushing encouraged in the second stage of labour?
(if no epidural) pushing encouraged when mother has desire, or the head is visible
(if epidural) at least an hour is waited before pushing and oxytocin is administered to a nulliparous woman if descent is poor
What is directed pushing?
If an epidural is in situ, the woman is instructed to push three times for about 10 seconds during each contraction
What are the indications for expedition of delivery?
if delivery is not imminent after 2 hours of pushing (1 hour in multiparous) or there is foetal distress
usually done with ventouse or forceps
What is the indication of episiotomy?
Reserved for when there is foetal distress or where the head is not passing over the perineum despite maternal effort, or if a large tear is likely.
How is episiotomy performed?
the perineum is infiltrated with local anaesthetic and a 3-5cm cut is made from the centre of the fourchette at a 45 degree angle to the mother’s right side of the perineum
What should the mother be asked to do when the head starts to deliver?
Stop pushing, pant slowly
Attendant may press on the perineum and the head to prevent a rapid delivery and perineal damage
What gets delivered after the head?
Anterior shoulder - then traction is directed upward to deliver the posterior shoulder
When should the umbilical cord be clamped?
After 1 minute, unless resuscitation is urgently required
What drug is administered IM to help the uterus contract once the shoulders are delivered
Oxytocin
Ergometrine and oxytocin often used, but this frequently leads to maternal vomitng
How is delivery of the placenta achieved?
Physiological
Active management of the third stage is where the midwife or doctor assist in delivering of the placenta. It involves a dose of intramuscular oxytocin to help the uterus contract, and careful traction to the umbilical cord to guide the placenta out of the uterus and vagina. Active management shortens the third stage and reduces the risk of bleeding, but can be associated with nausea and vomiting.
Active management is routinely offered to all women to reduce the risk of postpartum haemorrhage. It is also initiated if there is:
Haemorrhage
More than a 60-minute delay in delivery of the placenta (prolonged third stage)
What happens following placental delivery?
mother cleaned, made comfortable and encouraged to breast feed
Maternal observation continued for at least 2 hours
What is the effect/management of retained placenta?
Partial separation may cause blood loss in the uterus, causing it to enlarge and leading to hypovolaemia
1 hour is left for natural separation, after which the placenta is manually removed, blood cross matched and IV abx given
What is the managment of first and second degree tears?
(along with uncomplicated epiostomies and anal sphincter damage) are sutured under local anaesthetic
Absorbable synthetic material used, continues sutures for eh muscle and subcuticular layers for the skin.
Rectal and vaginal examination excludes sutures that are too deep and retained swabs
How are third and fourth degree tears managed?
Sphincter is repaired under epidural or spinal anaesthetic with the visualisation and asepsis of an operating theatre.
Torn ends of the external sphincter are mobilised and sutured, with the internal sphincter sutured separately if damaged.
Broad-spectrum antibiotics to reduce the risk of infection
Laxatives to reduce the risk of constipation and wound dehiscence
Physiotherapy to reduce the risk and severity of incontinence
Followup to monitor for longstanding complications
What is the long term effect of third/fourth degree tears?
Incontinence or urgency
