2.03 - Labour and Delivery Flashcards
Between which gestational weeks in labour and delivery normal?
G37-G42
Define the
a) first stage
b) second stage
c) third stage
of labour.
a) onset of labour (true contractions) until 10cm cervical dilatation.
b) from 10cm cervical dilatation until delivery of the baby.
c) from delivery of the baby until delivery of the placenta.
What are the phases of the first stage of labour?
Give the cervical measurement range, expected progression and characteristic of contractions for each phase.
Latent phase from 0-3cm dilation of the cervix. This progresses at around 0.5cm per hour. There are irregular contractions.
Active phase from 3-7cm dilation of the cervix. This progresses at around 1cm per hour. There are regular contractions.
Transition phase from 7-10cm dilation of the cervix. This progresses at around 1cm per hour. There are strong and regular contractions.
What are Braxton-Hicks contractions?
Occasional and irregular contractions of the uterus felt during T2-T3.
These are not true contractions and DO NOT indicate the onset of labour.
Staying hydrated and relaxing can help reduced Braxton-Hicks contractions.
What are the signs of labour?
- show (mucus plug from the cervix)
- rupture of membranes
- regular, painful contractions
- dilating cervix on examination
According to NICE (2017), the latent first stage of labour is when there are both:
- painful contractions
- effacement and dilation of the cervix
According to NICE (2017, the established first stage of labour is when there are both:
- regular, painful contractions
- dilation of the cervix ≥4cm
Define the following terms:
a) rupture of membranes (ROM)
b) spontaneous rupture of membranes (SROM)
c) premature rupture of membranes (PROM)
d) preterm prelabour rupture of membrane (P-PROM)
e) prolonged rupture of the membranes (PROM)
a) amniotic sac has ruptured
b) amniotic sac has ruptured spontaneously
c) amniotic sac has ruptured before the onset of labour
d) amniotic sac has ruptured before the onset of labour and before 37 weeks gestation (preterm)
e) the amniotic sac ruptures more than 18 hours before delivery
Define prematurity.
Birth before 37 weeks.
When is a premature baby considered non-viable?
Below 23 weeks gestation.
Generally, from 23 to 24 weeks, resuscitation is not considered in babies that do not show signs of life.
Babies born at 23 weeks have ~10% chance of survival.
World Health Organisation classes prematurity as:
a) <28 weeks
b) 28-32 weeks
c) 32-37 weeks
a) extreme preterm
b) very preterm
c) moderate to late preterm
What are the options for prophylaxis of preterm labour?
- vaginal progesterone
- cervical cerclage
Outline the role of vaginal progesterone in the prophylaxis of preterm labour.
Progesterone decreases the activity of the myometrium and prevents cervix remodelling in preparation for delivery.
Offered to women with a cervical length <25mm on vaginal ultrasound between 16 to 24 weeks gestation.
Outline the role of cervical cerclage in the prophylaxis of preterm labour.
Involves putting a stitch in the cervix to add support and keep it closed, under spinal or general anaesthetic. The stitch is removed when the woman goes into labour or reaches term.
Offered to women with a cervical length <25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had previous premature birth or cervical trauma.
How is preterm prelabour rupture of the membranes diagnosed?
Diagnosed by speculum examination revealing pooling of amniotic fluid in the vagina. No tests are required.
If there is doubt around the diagnosis of P-PROM, what tests can be performed?
IGFBP-1 is a protein present in high concentrations in amniotic fluid, which can be tested on vaginal fluid if there is doubt about rupture of membranes.
PAMG-1 is a similar alternative to IGFBP-1.
How is P-PROM managed?
Prophylactic erythromycin 250mg QDS for ten days, or until labour is established if within 10 days, to prevent the development of chorioamnionitis.
Induction of labour offered from 34 weeks gestation.
What is preterm labour with intact membranes?
Regular, painful contractions and cervical dilatation, without rupture of the amniotic sac and before 37 weeks gestation.
According to NICE (2017), how is preterm labour with intact membranes diagnosed
a) less than 30 weeks gestation?
b) more than 30 weeks gestation?
a) speculum examination to assess for cervical dilatation.
b) transvaginal ultrasound showing cervical length <15mm.
Outline the several options for improving the outcomes in preterm labour.
- fetal monitoring (CTG or intermittent auscultation)
- tocolysis
- maternal corticosteroids
- IV magnesium sulphate
- delayed cord clamping
Describe the role of tocolysis in preterm labour.
The use of medications (e.g. nifedipine, atosiban) to stop uterine contractions and delay delivery:
- allows time for further fetal development
- antenatal steroid administration
- transfer to specialist unit (NICU)
Used between 24 and 33+6 weeks gestation, allowing delay up to 48 hours.
Describe the role of antenatal steroids in premature labour.
Two doses of IM betamethasone, 24 hours apart, administered to mother.
Helps develop the fetal lungs and reduce respiratory distress syndrome after delivery.
Used in women with suspected premature labour of babies less than 36 weeks gestation.
Describe the role of magnesium sulphate in premature labour.
IV magnesium sulphate protects the fetal brain during premature labour, reducing the risk of cerebral palsy.
Given within 24 hours of delivery of preterm babies less than 34 weeks gestation:
- bolus
- infusion for 24 hours or until birth
What monitoring is required if administering IV magnesium sulphate?
Monitoring for magnesium toxicity at least four hourly:
- bradypnoea
- hypotension
- areflexia
What is induction of labour (IOL)?
Use of medications to stimulate the onset of labour.
Indications for IOL.
- G41-G42
- prelabour rupture of membranes
- fetal growth restriction
- pre-eclampsia
- obstetric cholestasis
- existing diabetes
- intrauterine fetal death
Describe the scoring system used to decide whether to induce labour?
Bishop score assesses:
- fetal station (max 3)
- cervical position (max 2)
- cervical dilatation (max 3)
- cervical effacement (max 3)
- cervical consistent (max 2)
A score ≥8 predicts a successful induction of labour.
A score ≤7 suggests cervical ripening required to prepare the cervix.
What are the options for IOL?
- membrane sweep
- vaginal prostaglandin E2
- cervical ripening balloon
- artificial rupture of membranes
Describe the role of membrane sweep in IOL.
Involves inserting a finger into the cervix to stimulate it and begin the process of labour within 48 hours.
It is used from 40 weeks gestation to attempt to initiate labour in women over the EDD.
Describe the role of vaginal prostaglandin E2 in IOL.
Insertion of a pessary into the vagina that slowly released local prostaglandins over 24 hours. This stimulates the cervix and uterus to cause the onset of labour.
Usually done in the hospital setting so women can be monitored, before being allowed home to await the full onset of labour.
Describe the role of cervical balloon ripening (CBR) in IOL.
Insertion and inflation of a balloon to dilate the cervix.
Used in women with a previous caesarean section, where vaginal prostaglandins have failed or in multiparous women.
Describe the role of artificial rupture of membranes in IOL.
Oxytocin infusion to induce labour if vaginal prostaglandins have been unsuccessful.
What medications can be given to induce labour in the case of intrauterine fetal death?
Oral mifepristone plus misoprostol.
What monitoring is required in IOL.
Cardiotocography (CTG) to assess fetal heart rate and uterine contractions, before and during induction of labour.
Bishop score before and during induction of labour to monitor the progress.
When there is slow progress following IOL, what are the options?
Most women will give birth within 24 hours of IOL. If they have not:
- further vaginal prostaglandins
- artificial rupture of membranes
- CRB
- elective caesarean section
What is the main complication of induction of labour with vaginal prostaglandins?
Uterine hyperstimulation.
Contraction of the uterus is prolonged and frequent, causing fetal distress and compromise.
What are the criteria for uterine hyperstimulation.
≥5 contractions in 10 minutes
or
painful contractions lasting ≥90s
PLUS ABNORMAL CTG
What are the complications of uterine hyperstimulation?
- fetal compromise (hypoxia and acidosis)
- emergency caesarean section
- uterine rupture
Management of uterine hyperstimulation.
- removal of vaginal prostaglandins
- stopping oxytocin infusion
- tocolysis with terbutaline*
*Hyperstimulation should resolve within 15-20 minutes due to short half life of vaginal prostaglandins. Consider tocolysis if no spontaneous resolve within this timeframe.
What measurements can be taken from cardiotocography (CTG)?
- fetal heart rate
- contractions of the uterus
Two tranducers 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 uterine contractions
Indications for continuous CTG monitoring.
- maternal sepsis
- maternal tachycardia (>120)
- pre-eclampsia
- antepartum haemorrhage
- delay in labour
- use of oxytocin
- significant meconium
- disproportionate maternal pain
Give a mnemonic used to assess CTGs.
DR C BRaVADO
DR - Define Risk based upon individual woman and pregnancy before assessing CTG.
C - Contractions
BRa - Baseline Rate
V - Variability
A - Accelerations
D - Decelerations
O - Overall impression
Give some reasons a pregnancy may be considered high risk.
Maternal medical illness:
- gestational diabetes
- hypertension
- asthma
Obstetric complications:
- multiple gestation
- post-date gestation
- previous caesarean section
- intrauterine growth restriction
- PROM
- oxytocin induction
- pre-eclampsia
Other risk factors:
- absence of prenatal care
- smoking
- drug abuse
Interpretation of contractions on CTG.
Assess the number of contractions present in a 10 minute period.
How long do the contractions last?
How strong are the contractions (assessed using palpation)?
Define the following terms and their respective CTG findings:
a) tachysystole
b) hypertonus
c) uterine hyperstimulation
a) ≥5 contractions in 10 minutes, with normal CTG
b) painful contraction lasting ≥90s, with normal CTG
c) tachysystole or hypertonus, with abnormal CTG
Interpretation of baseline rate of fetal heart on CTG.
Average heart rate of a fetus within a 10-minute window.
Normal fetal heart rate is between 110-160bpm.
Define fetal tachycardia and suggest some causes.
Baseline heart rate >160bpm:
- fetal hypoxia
- chorioamnionitis
- hyperthyroidism
- anaemia
Define fetal bradycardia.
Baseline heart rate <110bpm
When is it common to have a baseline heart rate between 100-120bpm?
- postdate gestation
- occiput posterior presentation
- occiput transverse presentation
Define severe prolonged fetal bradycardia and suggest some causes.
Baseline heart rate less than 80bpm for >3 minutes, indicating severe hypoxia:
- prolonged cord compression
- cord prolapse
- epidural and spinal anaesthesia
- maternal seizures
- rapid fetal descent
Interpretation of variability on CTG.
The variation in fetal heart rate from one beat to the next.
Normal variability is between 5-25bpm, indicating an intact neurological system in the fetus.
Define
a) reassuring variability
b) non-reassuring variability
c) abnormal variability
on CTG.
a) 5-25bpm
b) less than 5bpm for >30 minutes, or more than 25bpm for >15 minutes
c) less than 5bpm for >50 minutes, or more than 25bpm for >25 minutes.
Causes of reduced variability on CTG.
Fetal sleeping (should last no longer than 40 minutes).
Fetal acidosis due to hypoxia.
Fetal tachycardia.
Drugs (e.g. opiates, benzodiazepines, magnesium sulphate).
Prematurity <28 weeks.
Congenital heart abnormalities.
Interpretation of accelerations on CTG.
Accelerations are an abrupt increase in the baseline fetal heart rate of greater than 15bpm >15s.
Accelerations occuring alongside uterine contractions is a sign of a healthy fetus.
NB the absence of accelerations in an otherwise normal CTG is of uncertain significance.
Define and give the physiology of decelerations on CTG.
Abrupt decrease in the baseline fetal heart rate of greater than 15bpm for >15s.
In response to hypoxic stress, the fetus reduces its heart rate to preserve myocardial oxygenation and perfusion.
Give the types of decelerations present on CTG.
- early deceleration
- variable deceleration
- late deceleration
- prolonged deceleration
What is early deceleration?
When uterine contraction begins, increased fetal intracranial pressure increases vagal tone, reducing heart rate.
When uterine contractions end, fetal ICP reduces and vagal tone follows.
This type of deceleration is PHYSIOLOGICAL.
What is a variable deceleration?
The rapid fall in baseline fetal heart rate with a variable recovery phase, sometimes with no relationship to uterine contractions.
They are variable in their duration and is PATHOLOGICAL.
Mechanism of variable decelerations.
Umbilical cord compression:
1) Umbilical vein is occluded, causing acceleration of the fetal heart rate in response.
2) Umbilical artery is occluded, causing a subsequent rapid deceleration.
3) When pressure on the cord is reduced, another acceleration occurs and the baseline heart rate returns.
What is late deceleration?
Beginning at the peak of the uterine contraction, due to insufficient blood flow to the uterus and placenta.
There is recovery after the contraction ends.
Causes of reduced uteroplacental blood flow include:
- maternal hypotension
- pre-eclampsia
- uterine hyperstimulation
What is prolonged deceleration?
Deceleration lasting more than 2 minutes.
Non-reassuring if lasting between 2-3 minutes.
Abnormal if lasting longer than 3 minutes.
What is sinusoidal CTG pattern?
Sinusoidal CTG pattern has the following characteristics:
- smooth, regular, wave-like pattern
- frequency of 2-5 cycles a minute
- stable baseline rate
- no beat to beat variability
What are the causes of sinusoidal CTG pattern?
Associated with high rates of fetal morbidity and mortality:
- severe fetal hypoxia
- severe fetal anaemia
- fetal haemorrhage
- maternal haemorrhage
How can overall CTG impression be described?
- reassuring
- 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
How can abnormal CTG be managed?
- escalate to senior midwife and obstetrician
- further assessment for possible causes (e.g. uterine hyperstimulation, maternal hypotension, cord prolapse)
- conservative interventions (e.g. repositioning of mother, giving IV fluids for hypotension)
- fetal scalp stimulation
- fetal scalp blood sampling to test for fetal acidosis
- delivery of baby (instrumental delivery or emergency caesarean section)
What are the rule of 3s for fetal bradycardia?
3 minutes - call for help
6 minutes - move to theatre
9 minutes - prepare for delivery
12 minutes - deliver the baby
What is the role of oxytocin during labour?
Stimulates ripening of the cervix and contractions of the uterus.
What is the role of syntocinon in labour and delivery?
Synthetic infusion of oxytocin used to:
- induce labour
- progress labour
- improve frequency and strength of uterine contractions
- prevent or treat postpartum haemorrhage
What is the role of atosiban in labour and delivery?
Oxytocin receptor antagonist used as an alternative to nifedipine.
Action in tocolysis in premature labour.
Outline the role of ergometrine in labour and delivery.
Stimulates smooth muscle contraction in the uterus and blood vessels.
Used in the third stage of labour to induce delivery of the placenta.
Used postpartum to prevent and treat postpartum haemorrhage.
What are the side effects of ergometrine?
- hypertension*
- diarrhoea
- vomiting
- angina
*avoid in eclampsia
What is the role of prostaglandins in labour and delivery?
Stimulate contraction of uterine muscles and ripen the cervix before delivery.
Dinoprostone (prostaglandin E2) is used for IOL:
- vaginal pessaries
- vaginal tablets
- vaginal gel
Why are NSAIDs avoided during pregnancy?
Prostaglandins act as vasodilators, and lower blood pressure.
NSAIDs inhibit the action of prostaglandins, so can increase blood pressure.
What is the role of misoprostol in labour and delivery?
Prostaglandin analogue that agonises prostaglandin receptors to induce uterine contraction.
Used in the medical management of miscarriage.
Used alongside mifepristone for abortion, and IOL after intrauterine fetal death.
What is the role of mifepristone in labour and delivery?
An anti-progesterone medication, halting the pregnancy and ripening the cervix. It also enhances the effect of prostaglandins to stimulate contraction of the uterus.
Mifepristone is used alongside misoprostol for abortions, and IOL after intrauterine fetal death.
What is the role of nifedipine in labour and delivery?
CCB that reduces smooth muscle contraction in blood vessels and the uterus, therefore used to:
- reduce blood pressure in hypertension / pre-eclampsia
- tocolysis in premature labour
What is the role of terbutaline in labour and delivery?
Stimulates beta-2 adrenergic receptors to suppress uterine contractions.
Used for tocolysis in uterine hyperstimulation, notably when uterine contractions become excessive during induction of labour.
What is the role of carboprost in labour and delivery?
Synthetic prostaglandin analogue, stimulating uterine contraction.
Given as a deep intramuscular injection in postpartum haemorrhage, where oxytocin and ergometrine have been inadequate.
Contraindication of carboprost.
Asthma - causes life-threatening exacerbation of asthma.
What is the role of tranexamic acid in labour and delivery?
Antifibrinolytic medication to reduce bleeding.
Used in the prevention and treatment of postpartum haemorrhage.
Delay in the first stage of labour is considered when there is:
Less than 2cm of cervical dilatation in 4 hours
or
Slowing of progress in a multiparous women.
How is progress throughout the first stage of labour monitored?
Using a partogram, which records:
- cervical dilatation (4-hourly vaginal examination)
- descent of fetal head
- maternal pulse, blood pressure, temperature and urine output
- fetal heart rate
- frequency of contractions
- status of the membranes
- drugs and fluids that have been given
How is failure to progress in labour recorded on a partogram?
Dilation of the cervix is plotted against the duration of labour. When it takes too long for the cervix to dilate, the readings will cross to the right of the alert and action lines.
What action should be taken when the
a) alert line
b) action line
is crossed on a partogram?
a) amniotomy: artificial rupture of the membranes and a repeat examination after 2 hours.
b) escalate to obstetric-led care and senior decision-makers for appropriate action.
Delay in the second stage of labour is when the active second stage (pushing) lasts over:
- 2 hours in nulliparous women
- 1 hour in multiparous women
The second stage of labour depends upon the three Ps:
- Power (uterine contractions)
- Passenger (size, presentation and position of baby)
- Passage (shape and size of pelvis and soft tissues)
Power refers to what in the second stage of labour?
The strength of uterine contractions.
When there are weak uterine contractions, an oxytocin infusion can be used to stimulate the uterus.
Passenger refers to what in the second stage of labour?
Refers to four descriptive qualities of the fetus:
1) Size - macrosomic babies are more difficult to delivery (ie. shoulder distocia).
2) Attitude - the position of the fetus (ie. how the back is rounded, and how the head and limbs are flexed).
3) Lie - the position of the fetus in relation to the mother’s body.
4) Presentation - the part of the fetus that is closest to the cervix.
Types of fetal lie?
Types of fetal presentation?
Cephalic presentation - the head is first.
Shoulder presentation - the shoulder is first.
Breech presentation - the legs are first. This can be:
- Complete breech (hips and knees flexed)
- Frank breech (hips flexed and knees extended)
- Footling breech (foot hanging through the cervix)
When there are problems with the second stage of labour, what are the possible interventions?
- changing positions
- encouragement
- analgesia
- oxytocin infusion
- episiotomy
- instrumental delivery
- caesarean section
NICE (2017) define delay in the third stage of labour as:
- more than 30 minutes with active management
- more than 60 minutes with physiological management
What is the active management of the third stage of labour?
IM oxytocin and controlled cord traction.
What are the options for managing failure to progress?
- amniotomy
- oxytocin infusion
- instrumental delivery
- caesarean section
Describe the role of oxytocin infusion in failure to progress?
Stimulate uterine contractions during labour, started as a low rate and titrated up at intervals of 30 minutes.
The aim is for 4-5 contractions per 10 minutes.
How can pain be managed in labour without medication?
Antenatal classes help prepare women for what to expect in labour:
- understanding what to expect
- having good support
- being in a relaxed environment
- controlled breathing
What are the options for pain relief during labour?
- paracetamol / codeine
- gas and air (entonox)
- IM pethidine or diamorphine
- PCA IV remifentanil
- epidural
What is an epidural?
Insertion of a catheter into the epidural space in the lower back, through which local anaesthetic medications are infused.
Anaesthetic options include levobupivacaine or bupivacaine.
What are the adverse effects of an epidural?
- headache after insertion
- hyotension
- motor weakness in legs*
- nerve damage
- prolonged second stage
- increased probability of instrumental delivery
*indicated catheter is sited in subarachnoid space.
What is umbilical cord prolapse?
When the umbilical cord descends below the presenting part of the uterus and through the cervix into the vagina, following rupture of the fetal membranes.
Risk factors for umbilical cord prolapse.
Fetus in abnormal lie after G37 provides space for the cord to prolapse below the presenting part:
- unstable
- transverse
- oblique
What is the major complication of umbilical cord prolapse?
Compression of the cord, resulting in fetal hypoxia.
How is umbilical cord prolapse diagnosed?
Suspect where there are signs of fetal distress on CTG.
Diagnosis via vaginal examination plus speculum examination.
How should cord prolapse be managed?
Emergency caesarean section.
While awaiting caesarean section, lay woman in left lateral position or knee-chest position, as these utilise gravity to draw the fetus away from the pelvis and reduce compression on the cord.
Tocolytic medications (e.g. terbutaline) can be used to minimise contractions.
Why should the cord have minimum handling whilst waiting for delivery in prolapse?
Handing causing vasospasm, which will worsen fetal hypoxia and distress.
What is shoulder distocia?
The anterior shoulder of the baby becomes stuck behind the pubic symphysis of the pelvis, after the head has been delivered.
An obstetric emergency!!
What is the most common cause of shoulder distocia?
Macrosomia secondary to gestational diabetes.
How does shoulder distocia present?
Difficulty delivering the face and the head, and obstruction in delivery the shoulders after delivery of the head.
The head will not turn sideways as expected after delivery of the head.
The turtle-neck sign is where the head is delivered but then retracts back into the vagina.
How should shoulder dystocia be managed?
MDT approach:
- experienced midwifes
- obstetricians
- paediatricians
- anaesthetics
There are several techniques used to manage the position and deliver the baby:
- episiotomy
- pressure to anterior shoulder
- McRoberts manoeuvre
- Zavanelli manoeuver
What is an episiotomy and what is its use in shoulder dystocia?
A cut along the perineum to enlarge the vaginal opening and reduce the risk of perineal tears.
Cut is made at 45° diagonally, to avoid damaging the anal sphincter.
How does pressure to the anterior shoulder help in shoulder dystocia?
Pressing on the suprapubic region of the abdomen puts pressure on the anterior shoulder, to encourage it down and under the pubic symphysis.
What is McRoberts manoeuvre in shoulder dystocia?
Hyperflexion of the mother at the hip (bringing her knees to the abdomen), providing a posterior pelvic tilt.
This lifts the pubic symphysis up and out of the way.
What is Zavanelli’s manoeuvre in shoulder dystocia?
Involves pushing the baby’s head back into the vagina, to allow the baby to be delivered by emergency caesarean section.
Complications of shoulder dystocia.
- fetal hypoxia
- cerebral palsy
- Erb’s palsy
- perineal tears
- postpartum haemorrhage
What is Erb’s palsy?
An upper brachial plexus injury (C5, C6) as a result of a stretching injury during a difficult vaginal delivery.
The affected limb:
- hangs limply
- medially rotated
- pronated
- wrist flexion
What is instrumental delivery?
Vaginal delivery of a baby assisted by either a ventouse suction cup or forceps.
Are antibiotics recommended after instrumental delivery?
A single dose of co-amoxiclav is recommended after instrumental delivery to reduce risk of maternal infection.
Indications of instrumental delivery.
- failure to progress
- fetal distress
- maternal exhaustion
- control of the head in various fetal positions
Risk factors for instrumental delivery.
Epidural for analgesia
Risks of instrumental delivery to the mother.
- postpartum haemorrhage
- episiotomy
- perineal tears
- injury to anal sphincter
- incontinence of the bladder or bowel
- nerve injury (obturator or femoral)
What is ventouse delivery?
A suction cup on a cord, that goes on the baby’s head to pull the baby out of the vagina.
What are the key complications of ventouse delivery to the baby?
Capput succedaneum - oedema between the skull and scalp.
What is forceps delivery?
The use of tongs that grip the baby’s head, with careful traction applied to pull the head from the vagina.
What are the complications of forceps delivery to the baby?
Facial nerve palsy, with facial paralysis on one side.
Can also leave bruises on the face, and rarely baby’s develop fat necrosis (spontaneously resolves).
What nerves are most commonly injured during instrumental delivery?
Femoral nerve (compression against the inguinal canal during a forceps delivery).
Obturator nerve (compression by the forceps or by fetal head during normal delivery).
What are the clinical signs of
a) femoral nerve injury
b) obturator nerve injury
following instrumental delivery?
What is the prognosis?
a) weakness of knee extension; loss of patella reflex; numbness of the anterior thigh and medial lower leg.
b) weakness of hip adduction and rotation; numbness of medial thigh.
Usually spontaneously resolves within 6-8 weeks.
What nerves are commonly injured during normal vaginal delivery?
Lateral cutaneous nerve (prolonged flexion at the hip).
Lumbosacral plexus (compression by fetal head).
Common peroneal nerve (compression on the head of the fibula).
What are the clinical signs of:
a) lateral cutaneous nerve of the thigh injury
b) lumbosacral plexus injury
c) common peroneal nerve injury
a) numbness of the anterolateral thigh.
b) foot drop; numbness of the anterolateral thigh, lower leg and foot.
c) foot drop; numbness in the lateral lower leg.
What are perineal tears?
Where the external vaginal opening is too narrow to accommodate the baby, the skin and tissues tear as the baby’s head passes.
Risk factors for perineal tears.
- nulliparity
- macrosomia (>4kg)
- shoulder dystocia
- occipito-posterior position
- instrumental delivery
Describe the four degrees of perineal tear.
First degree - injury limited to the frenulum of the labia minora and superficial skin.
Second degree - injury including the perineal muscles, but not affected the anal sphincter.
Third degree - injury including the anal sphincter, but not affecting the rectal mucosa.
Fourth degree - injury including the rectal mucosa.
How are perineal tears managed?
Sutures to correct the injury*.
Broad spectrum abx to reduce risk of infection.
Laxatives to reduce risk of constipation and wound dehiscence.
Physiotherapy to reduce risk and severity of incontinence.
Followup to monitor for longstanding complications.
Elective caesarean section in subsequence pregnancies.
*first degree tears do not usually require any sutures.
Short-term complications of perineal tears.
- pain
- infection
- bleeding
- wound dehiscence
Long-term complications of perineal tears.
- urinary incontinence
- anal incontinence (3-4th degree)
- fistula between vagina and bowel
- dyspareunia
- mental health consequences
How can the risk of perineal tear be limited?
- episiotomy
- perineal massage from G34
What are the management options for the third stage of labour?
Physiological management - the placenta is delivered by maternal effort without medications or cord traction.
Active management - assisted delivery of the placenta with medication or cord traction.
Indications for active management of the third stage of labour.
Routinely offered to all women to reduce the risk of postpartum haemorrhage.
Also initiated if:
- haemorrhage
- prolonged third stage (>60 minutes)
Describe active management of the third stage of labour.
1) IM dose of oxytocin after delivery of the baby.
2) Cord clamped and cut between 3-5 minutes of birth.
3) Controlled cord traction carefully applied during uterine contractions to help deliver the placenta.
4) After delivery of the placenta, massage the uterus until it is contracted and firm.
How much blood loss meets the criteria for postpartum haemorrhage?
Vaginal delivery >500ml
Caesarean section >1000ml
Define the following in terms of blood loss:
a) minor PPH
b) moderate PPH
c) severe PPH
a) 500-1000ml blood loss
b) 1000-2000ml blood loss
c) >2000ml blood loss
Define
a) primary PPH
b) secondary PPH
a) bleeding within 24 hours of birth.
c) bleeding between 24 hours and 12 weeks after birth.
What are the causes of PPH?
Four Ts:
- Tone (uterine atony)
- Trauma (e.g. perineal tear)
- Tissue (ie. retained placenta)
- Thrombin (ie. bleeding disorder)
Risk factors for PPH.
- previous PPH
- multiple pregnancy
- obesity
- macrosomia
- prolonged labour
- pre-eclampsia
- placenta accreta
- retained placenta
- instrumental delivery
- episiotomy / perineal tear
How can the risk of PPH be reduced?
Treat anaemia during the antenatal period.
Giving birth with an empty bladder (a full bladder reduces uterine contraction).
Active management of the third stage.
IV tranexamic acid used during caesarean section.
How is PPH initially managed?
Managed by an experienced MDT:
- resuscitation with A-E approach
- lie the woman flat, keep her warm and communicate with her and the partner
- insert two large-bore cannulas
- bloods for FBC, U&E and clotting screen
- cross match 4 units of blood
- warmed IV fluid and blood resuscitation
- oxygen (regardless of saturations)
- FFP if clotting abnormalities or after 4 units of blood transfusion
In severe cases, activate the major haemorrhage protocol.
How are the treatment options for stopping bleeding in PPH categorised?
- mechanical
- medical
- surgical
What are the mechanical treatment options for PPH?
- rubbing the uterus through the abdomen to stimulate contraction
- catheterisation (bladder distension prevents uterine contraction)
What are the medical treatment options for PPH?
- oxytocin (40 units in 500ml IV infusion)
- ergometrine (IV/IM)
- carboprost (IM)
- misoprostal (SL)
- tranexamic acid (IV)
What are the surgical treatment options for PPH?
- intrauterine balloon tamponade
- uterine artery ligation
- hysterectomy
What are the most common causes of secondary PPH?
- retained POC
- infection (endometritis)
How is secondary PPH investigated?
- ultrasound for retained POC
- endocervical and HVS for infection
How is secondary PPH managed?
- surgical evaluation for retained POC
- antibiotics for infection
How are elective caesareans performed?
A planned date on which a woman will come in for delivery, after 39 weeks gestation.
Usually performed under spinal anaesthetic.
Indications for elective caesarean section.
- previous caesarean
- symptomatic after previous perineal tear
- placenta praevia
- vasa praevia
- breech presentation
- multiple pregnancy
- uncontrolled HIV infection
- cervical cancer
What are the categories of emergency caesarean section?
Cat 1: immediate threat to life of mother or baby. Deliver within 30 minutes.
Cat 2: no imminent threat, but urgent delivery required due to compromise of the mother or baby. Deliver within 75 minutes.
Cat 3: Delivery is required, but mother and baby are stable.
Cat 4: Elective caesarean.
What are the two commonly used incisions for Caesarean section?
Pfannenstiel incision - a curved incision two fingers width above the pubic symphysis.
Joel-cohen incision - a straight incision above the pubic symphysis (recommended)
After the initial incision with a scalpel, what are the benefits of blunt dissection in caesarean section?
- less bleeding
- shorter operating times
- less risk of injury to baby
What are the layers of the abdomen that need to be dissected during a caesarean?
- skin
- subcutaneous tissue
- fascia / rectus sheath
- rectus abdominis muscle
- peritoneum
- vesicouterine peritoneum
- uterus (perimetrium, myometrium and endometrium)
- amniotic sac
Which is the preferred anaesthetic option in caesarean section?
Spinal anaesthetic:
- safer
- fewer complications
- faster recovery
It takes longer the initiate than a general anaesthetic, so this may be opted for in emergency caesarean section.
Risks associated with having an anaesthetic.
- anaphylaxis
- hypotension
- headache
- urinary retention
- nerve damage (spinal anaesthesia)
- haematoma (spinal anaesthesia)
- sore throat (general anaesthesia)
- damage to teeth or mouth (general anaesthesia)
Complications of caesarean section.
- bleeding
- infection
- pain
- VTE
- aspiration pneumonitis
How can caesarean section complications be reduced?
Oxytocin infusion to reduce the risk of PPH.
LMWH prophylaxis for VTE.
Prophylactic abx for infection.
H2 receptor antagonists or PPIs for aspiration pneumonitis.
Pain relief for pain.
What are the key causes of sepsis in pregnancy?
- chorioamnionitis
- urinary tract infections
What is chorioamnionitis?
Infection of the chorioamniotic membranes and amniotic fluid, occuring later in pregnancy and during labour.
Presentation of chorioamnionitis.
- abdominal pain
- uterine tenderness
- vaginal discharge
Plus non-specific signs of sepsis:
- fever
- tachycardia
- tachypnoea
- hypoxaemia
- altered consciousness
- oligouria
- fetal compromise on CTG
How are all patients admitted to maternity inpatient units monitored?
MEOWS chart - maternity early obstetric warning system.
Presentation of urinary tract infection.
- dysuria
- urinary frequency
- suprapubic pain
- renal angle pain (pyelonephritis)
- vomiting (pyelonephritis)
Plus non-specific signs of sepsis.
For patients with suspected sepsis, how should they be investigated?
- FBC (assess WCC / neutrophils for infection)
- U&Es (assess kidney function ?AKI)
- LFTs (assess liver function, possible source of infection ?acute cholecystitis)
- CRP (assess inflammation)
- clotting (?DIC)
- blood cultures (identify bacteraemia)
- blood gas (lactate, pH and glucose)
How can the source of infection be identified in maternal sepsis?
- urine dipstick and culture (?UTI)
- high vaginal swab (?chorioamnionitis)
- throat swab
- sputum culture
- wound swab after procedures
How should maternal sepsis be managed?
Involve senior midwifes and obstetricians early in the care.
Initiate sepsis six.
Continuous maternal (MEWOS) and fetal monitoring (CTG).
Emergency caesarean section if fetal distress, under GA.
Broad spectrum antibiotics as per local guidelines.
What is the sepsis 6?
Give 3:
- oxygen (target SpO2 >94%)
- empirical broad spectrum abx
- IV fluids
Take 3:
- blood lactate
- blood cultures
- urine output
What is amniotic fluid embolism?
During labour and delivery, amniotic fluid passes into the mother’s blood.
Risk factors for amniotic fluid embolism.
- increasing maternal age
- induction of labour
- caesarean section
- multiple pregnancy
Presentation of amniotic fluid embolism.
Acute onset of symptoms:
- SOB
- hypoxia
- hypotension
- coagulopathy
- haemorrhage
- tachycardia
- confusion
- seizures
- cardiac arrest
Management of amniotic fluid embolism.
Call for help immediately from senior obstetricians, anaesthetics, haematologists.
A - secure the airway
B - provide oxygen for hypoxia
C - IV fluids to treat hypotension / blood transfusion in haemorrhage
D - Treat seizures
E - Exposure
CPR and immediate caesarean section are required if cardiac arrest occurs.
What are the types of uterine rupture?
During labour, the muscle layer of the uterus ruptures.
With an incomplete rupture, the perimetrium surrounding the uterus remains intact.
With a complete rupture, the serosa ruptures and the contents of the uterus are released into the peritoneal cavity.
Risk factors for uterine rupture.
- previous caesarean section
- previous uterine surgery
- vaginal birth after caesarean (VBAC)
- increased BMI
- high parity
- induction of labour
Presentation fo uterine rupture.
Acutely unwell mother and abnormal CTG.
Signs and symptoms of massive bleeding:
- abdominal pain
- vaginal bleeding
- ceasing of uterine contractions
- hypotension
- tachycardia
- collapse
Management of uterine rupture.
Obstetric emergency - early senior involvement with resuscitation and transfusion as required.
Emergency caesarean section to remove the baby, stop the bleeding and repair or remove the uterus.
What is uterine inversion?
A rare complication of birth, where the fundus of the uterus drops down through the uterine cavity and cervix.
It can be the result of pulling too hard on the umbilical cord during active management of the third stage of labour.
Presentation of uterine inversion.
Sever PPH with maternal shock or collapse.
Feel the uterus on bimanual examination (incomplete); see the uterus at the introitus of the vagina (complete).
What are the management options for uterine inversion?
- Johnson manoeuvre
- hydrostatic methods
- surgery
What is the Johnson manoeuvre in uterine inversion?
Using a hand to push the fundus back up into the abdomen, with medications given to create a uterine contraction (e.g. oxytocin, ergometrine).
What are the hydrostatic methods used to manage uterine inversion?
Where the Johnson manoeuvre fails, the vagina can be filled with fluid to ‘inflate’ the uterus back to the normal position.
It requires a tight seal at the entrance of the vagina, which can be challenging to achieve.
What are the surgical methods used to manage uterine inversion?
When the Johnson manoeuvre and hydrostatic methods fail, a laparotomy is performed and the uterus is returned to the normal position.
