Management of Delivery Flashcards

Question 1

Q

What is the fetal mortality associated with haemorrhage at membrane rupture in vasa praevia?

a. 5%
b. 10%
c. 20%
d. 40%
e. 60%

Answer

A

E - 60%

The fetal mortality associated with haemorrhage secondary to rupture of a vasa praevia is as high as 60%

Question 2

Q

What is the normal blood volume of a fetus at term?

a. 10-20ml/kg
b. 40-60ml/kg
c. 80-100ml/kg
d. 150-200ml/kg
e. 250-500ml/kg

Answer

A

C - 80-100ml/kg

Normal fetal blood volume at term is 80-100ml/kg - ~350ml only for a 3.5kg fetus.

Question 3

Q

A primigravida is found to have persistent vasa praevia following an ultrasound scan at 32/40. At what gestation is elective delivery advised?

a. From 34/40
b. From 35/40
c. From 36/40
d. From 37/40
e. From 38/40

Answer

A

A - From 34/40

Patients with vasa praevia should be delivered electively from 34/40 under steroid cover. Decision on whether or not to electively admit patients to hospital from 30-32/40 should be based on an individualised assessment of the risk of preterm labour.

Question 4

Q

A patient is admitted for an elective caesarean section for placenta praevia. During the morning briefing, the theatre team leader asks if cell-salvage is required. At what anticipated blood loss threshold should routine use of cell salvage be utilised at caesarean section?

a. >1000ml
b. >1500ml
c. >1750ml
d. >2000ml
e. >2500ml

Answer

A

B - >1500ml

Where intra-operative blood loss is expected to be greater than 1500ml, cell salvage should be recommended

Question 5

Q

What is the estimated incidence of placenta praevia at term?

a. 1 in 100
b. 1 in 200
c. 1 in 500
d. 1 in 1000
e. 1 in 1500

Answer

A

B - 1 in 200

The estimated incidence of placenta praevia at term is as high as 0.5% - 1 in 200.

Question 6

Q

When should women with asymptomatic, uncomplicated placenta praevia be delivered?

a. 35-36/40
b. 36-37/40
c. 37-38/40
d. 38-39/40
e. 39-40/40

Answer

A

B - 36-37/40

Patients with an uncomplicated placenta praevia are recommended to undergo late preterm delivery at 36-37 weeks of gestation

Question 7

Q

A patient undergoes an elective caesarean section for placenta praevia. Following delivery of the fetus, the placenta is noticed to be morbidly adherent in parts to the underlying myometrium. This had not been reported antenatally. What proportion of placenta accreta remains undiagnosed prior to delivery?

a. Up to 1/5
b. Up to 1/4
c. Up to 1/3
d. Up to 1/2
e. Up to 2/3

Answer

A

E - Up to 2/3

It is estimated that as many as 2/3 of placenta accreta are only definitively diagnosed at delivery

Question 8

Q

When should women with asymptomatic, uncomplicated placenta accreta be delivered?

a. 35-36/40
b. 36-37/40
c. 37-38/40
d. 38-39/40
e. 39-40/40

Answer

A

A - 35-36/40

Patients with an uncomplicated placenta accreta are recommended to undergo delivery at 35-36/40

Question 9

Q

A primigravida attends delivery suite in early labour. The midwife who examines the patient on admission suspects a breech presentation and asks the registrar on-call to confirm this by means of ultrasound. A footling breech presentation is confirmed. The woman is 5cm on VE and plans are made for delivery by caesarean section. What proportion of term breech presentations are undetected?

a. 20-30%
b. 15-20%
c. 10-15%
d. 5-10%
e. <5%

Answer

A

A - 20-30%

20-32.5% of term breech presentations are undetected. These infants generally have worse outcomes than those where the diagnosis is made in advance of labour and a plan for delivery made. Particular care should be taken in the case of patients with a history of breech presentation, as recurrence rates are as high as 10%. Patients with breech babies who present in labour require individualised assessment and counselling on their mode of delivery – those at or near the second stage should not typically be offered routine LSCS

Question 10

Q

During a vaginal breech birth, at what time interval from delivery of the buttocks would assisted delivery be advised if the head has not yet delivered?

a. 2 minutes
b. 3 minutes
c. 5 minutes
d. 6 minutes
e. 7 minutes

Answer

A

C - 5 minutes

While a ‘hands-off’ approach to vaginal breech delivery is generally advised (owing to the reflex extension of the neck and arms in response to tactile stimulation), assistance without traction may be indicated where there is evidence of delay or poor fetal condition. Delay is defined as an interval of 5 minutes or more from buttocks to head, or 3 minutes or more from umbilicus to head.

Question 11

Q

During a vaginal breech birth, at what time interval from delivery of the umbilicus would assisted delivery be advised if the head has not yet delivered?

a. 2 minutes
b. 3 minutes
c. 5 minutes
d. 6 minutes
e. 7 minutes

Answer

A

B - 3 minutes

While a ‘hands-off’ approach to vaginal breech delivery is generally advised (owing to the reflex extension of the neck and arms in response to tactile stimulation), assistance without traction may be indicated where there is evidence of delay or poor fetal condition. Delay is defined as an interval of 5 minutes or more from buttocks to head, or 3 minutes or more from umbilicus to head.

Question 12

Q

Which of the following manoeuvres is not recommended by the RCOG in assisting delivery of the vaginal breech due to concerns around hyper-extension of the fetal neck:

a. Lovsett’s manoeuver
b. Maurice-Smellie-Veit manoeuver
c. Forceps for after-coming head
d. Suprapubic pressure
e. Burns-Marshall manoeuver

Answer

A

E - Burns-Marshall Manoeuvere

Evidence regarding techniques of assisted breech delivery is lacking. Gentle rotation should be used to ensure the spine remains anterior and once the scapula is visible, the arms can be ‘hooked’ down by flexing the elbow with a finger across the chest, or face if nuchal (Lovsett’s). Delivery of the head is then achieved with Maurice-Smellie-Veit or forceps. Suprapubic pressure may aid flexion where delay is thought to be secondary to an extended neck. The Burns Marshall method is not advised due to concerns around over-extension of the fetal neck.

Question 13

Q

What is the incidence of head entrapment at delivery during preterm breech delivery?

a. 2%
b. 3%
c. 7.5%
d. 12%
e. 14%

Answer

A

E - 14%

Labour in preterm breeches should be managed as per term though a specific complication – seen in up to 14% - is of the fetal trunk delivering through an incompletely dilated cervix. Lateral incision on the cervix at 2, 6 and 10 o’clock are recommended to release the head if required.

Question 14

Q

What is the risk of caesarean section delivery in women planning vaginal breech birth?

a. 25%
b. 33%
c. 40%
d. 50%
e. 66%

Answer

A

C - 40%

Women planning vaginal breech birth have a higher risk of caesarean section (40%) than equivalent women planning cephalic.

Question 15

Q

You are called to review a primigravida who has presented in spontaneous preterm labour with a breech presentation at 30/40. On examination, the fetal trunk appears to have delivered though the head is trapped by an incompletely dilated cervix. You decide to release the fetal head by means of lateral cervical incisions. At what points on the cervix (in terms of a clock face) should these be made?

a. 3 and 9 o’clock
b. 6 and 12 o’clock
c. 2, 10 and 6 o’clock
d. 5, 7 and 12 o’clock
e. 1, 5, 7 and 11 o’clock

Answer

A

C - 2, 10 and 6 o’clock

3 lateral incisions to the cervix are recommended owing to location of the cervical arteries – 2, 10 and 6 o’clock.

Question 16

Q

What precautions should be considered at CS in patients on therapeutic doses of heparin?

a. Wound drain and skin closure with interrupted sutures
b. Staples closure and negative pressure dressing
c. Use of dissolvable sutures at skin closure
d. Haemostatic matrix routinely applied to uterine incision prior to closure
e. Closure of peritoneum where possible and drain to rectus sheath

Answer

A

A - Wound drain and skin closure with interrupted sutures

In patients receiving therapeutic doses of LMWH, wound drains (abdominal and rectus sheath) should be considered at caesarean section and the skin incision should be closed with interrupted sutures to allow drainage of any haematoma.

Question 17

Q

A Jehovah’s Witness, known to be Rh-ve is admitted for an elective Caesarean Section for placenta praevia. Intra-operative cell salvage is used and following a major PPH of 1.7L, she receives an autologous transfusion. The baby was admitted to the SCBU after birth and its rhesus status is unknown. How should the mother be managed post-transfusion?

a. Kleihaur testing at 30-40 minutes and anti-D if required
b. 250iU of anti-D routinely and Kleihaur testing to guide further requirement
c. 500iU of anti-D routinely and Kleihaur testing to guide further requirement
d. 1500iU of anti-D routinely and Kleihaur testing to guide further requirement
e. No anti-D required

Answer

A

D - 1500iU of anti-D routinely and Kleihaur to guide further requirement

Where cell salvage is used during caesarean in non-sensitised, rhesus negative women, a minimum of 1500iU anti-D should be given, where the cord blood is either rhesus positive or unknown. IOCS and leucocyte depletion filters have been shown to be effective at removing the common markers of amniotic fluid contamination though cannot remove fetal red cells.

Question 18

Q

A patient requires several units of RBCs following a massive haemorrhage during a caesarean section for placenta praevia. You consider that she might also require additional blood components. What is the recommended dose and ratio for use of FFP in an obstetric population?

a. 12-15ml/kg FFP given for every 4 units of RBCs
b. 12-15ml/kg FFP given for every 6 units of RBCs
c. 22-25ml/kg FFP given for every 4 units of RBCs
d. 22-25ml/kg FFP given for every 6 units of RBCs
e. 5ml/kg FFP given for every 6 units of RBCs

Answer

A

B - 12-15ml/kg FFP given for every 6 units of RBCs

The optimum dose or ratio of FFP to RBCs remains unknown. In obstetric practice, 12-15ml/kg should be given for every 6 units of RBCs used during major haemorrhage. Subsequent transfusion should be guided by results of clotting tests – aiming to maintain PT and APTT at ratios <1.5x normal

Question 19

Q

How long does fresh-frozen plasma take to thaw after requesting?

a. No thawing required – administer via fluid warmer
b. 15 minutes
c. 20 minutes
d. 30 minutes
e. 1 hour

Answer

A

D - 30 minutes

Once requested, FFP takes at least 30 minutes to thaw and issue.

Question 20

Q

Following a massive obstetric haemorrhage at a caesarean section for placenta praevia, you note that a patient who is Rhesus –ve has received a single dose of FFP from a Rhesus +ve donor. How much anti-D is required to counteract a single dose of FFP in such an instance?

a. 250iU
b. 500iU
c. 1000iU
d. 1500iU
e. No anti-D required

Answer

A

E - No anti-D indicated

Sensitisation following administration of RhD positive FFP or Cryoprecipitate to RhD negative women is extremely unlikely – hence no anti-D prophylaxis is indicated. FFP and cryoprecipitate should ideally be group matched though a different group is acceptable providing anti-A or B titres are not high.

Question 21

Q

A coagulation screen taken during a PPH returns abnormal results and your consultant suggests the patient may benefit from cryoprecipitate. What is the goal of cryoprecipitate therapy during obstetric haemorrhage?

a. Keep platelet count >50
b. Keep platelet count >75
c. Keep fibrinogen >1
d. Keep fibrinogen >1.5
e. Maintain normal APTT

Answer

A

D - Keep fibrinogen >1.5

Cryoprecipitate should be issued at a standard dose of 2x 5 unit pools early in major haemorrhage. Subsequent administration should be guided by fibrinogen results – the aim being to keep levels >1.5g/L.

Question 22

Q

What is the standard dose of cryoprecipitate used in obstetric haemorrhage?

a. Single 5 unit pool
b. 2x 5 unit pools
c. 3x 5 unit pools
d. 2x 10 unit pools
e. Single 10 unit pool

Answer

A

B - 2x 5 unit pools

Cryoprecipitate should be issued at a standard dose of 2x 5 unit pools early in major haemorrhage. Subsequent administration should be guided by fibrinogen results – the aim being to keep levels >1.5g/L.

Question 23

Q

What is the goal of FFP therapy in acute obstetric haemorrhage?

a. Platelet count >50
b. APTT and PT <1.5x normal
c. INR <2.5
d. Fibrinogen >1.5x normal
e. Platelet count >75

Answer

A

B - APTT and PT <1.5x normal

The aim of FFP is to maintain APTT and PT less than 1.5 times normal.

Question 24

Q

What is the overall risk of cord prolapse in pregnancy?

a. 0.1-0.6%
b. 0.7-0.9%
c. 1.1-1.5%
d. 1.5-1.8%
e. 1.8-2.1%

Answer

A

A - 0.1-0.6%

The overall incidence of cord prolapse ranges from 0.1 to 0.6% though is considerably higher in breech presentation – around 1%

Question 25

Q

What is the risk of cord prolapse in breech presentation?

a. 0.5%
b. 1%
c. 1.7%
d. 2.3%
e. 2.9%

Answer

A

B - 1%

The overall incidence of cord prolapse ranges from 0.1 to 0.6% though is considerably higher in breech presentation – around 1%

Question 26

Q

Which of the following is NOT a recognised risk factor for cord prolapse?

a. Low birthweight
b. Induction of labour with balloon catheter
c. Induction of labour with vaginal prostaglandins
d. Congenital abnormality
e. Low lying placenta

Answer

A

C - Induction of labour with vaginal prostaglandins

Numerous risk factors for cord prolapse are described – both general and interventional risks. Approximately half of all cord prolapse is preceded by an obstetric indication. Induction of labour with a balloon catheter is a recognised risk factor, though the risk is not thought to be altered by prostaglandin induction.

Question 27

Q

The emergency bell is pulled on labour ward after a midwife performs an amniotomy as part of a routine post-dates induction of labour and feels the cord prolapse through the open cervix. What proportion of cases of cord prolapse are preceded by obstetric intervention (amniotomy, ECV et al.)?

a. 1/5
b. 1/4
c. 1/2
d. 2/3
e. 3/4

Answer

A

C - 1/2

Numerous risk factors for cord prolapse are described – both general and interventional risks. Approximately half of all cord prolapse is preceded by an obstetric indication. Induction of labour with a balloon catheter is a recognised risk factor, though the risk is not thought to be altered by prostaglandin induction.

Question 28

Q

What is the overall rate of perinatal mortality associated with cord prolapse?

a. 0.5%
b. 0.9%
c. 3.5%
d. 9.1%
e. 15%

Answer

A

D - 9.1%

The overall perinatal mortality associated with cord prolapse is quoted as 91 in 1000 or 9.1%, the vast majority of which in the hospital setting is attributable to either prematurity or congenital abnormality – both recognised risk factors for the complication. Mortality is increased more than ten-fold where cord prolapse occurs outwith hospital.

Question 29

Q

What is the increase in rate of perinatal mortality for cord prolapse occurring in such a community setting compared with in hospital?

a. 3-fold
b. 5-fold
c. 10-fold
d. 20-fold
e. 25-fold

Answer

A

C - 10-fold

Perinatal mortality is increased ten-fold when cord prolapse occurs outwith hospital when compared to inpatients.

Question 30

Q

At what threshold of depth should the sub-cut fat be routinely sutured at caesarean section?

a. The sub-cut fat should be sutured in all women
b. 2cm
c. 3cm
d. 4cm
e. 5cm

Question 31

Q

A ‘low-risk’ Para 3 (all vaginal births) discusses options for delivery with her community midwife. She wishes to deliver in a setting which gives her the greatest chance of achieving a spontaneous vaginal birth. In what setting should she be advised to deliver?

a. Home
b. Free-standing midwifery unit
c. Co-located midwifery led unit
d. Obstetric unit
e. Rate of spontaneous vaginal birth equivalent across all birth settings

Question 32

Q

A ‘low-risk’ primigravida discusses options for delivery with her community midwife. She wishes to deliver in a setting which gives her the greatest chance of achieving a spontaneous vaginal birth. Bearing in mind her wishes, in what setting should she be advised to deliver?

a. Home
b. Free-standing midwifery unit
c. Co-located midwifery led unit
d. Obstetric unit
e. Rate of spontaneous vaginal birth equivalent across all birth settings

Answer

A

B - Free-standing midwifery unit

Question 33

Q

Which of the following has NOT been shown to influence the likelihood of requiring a caesarean section in labour?

a. Continuous support in labour
b. Induction beyond 41 weeks gestation
c. Immersion in water
d. Use of a partogram with a 4 hour ‘action-line’
e. Consultant obstetrician involvement in any decision making for CS

Answer

A

C - Immersion in water

Question 34

Q

How far above the symphysis pubis should the transverse abdominal incision use in caesarean section by made?

a. 1cm
b. 2cm
c. 3cm
d. 4cm
e. 5cm

Question 35

Q

How soon following caesarean section should the wound dressing be removed?

a. 24 hours
b. 48 hours
c. 72 hours
d. 5 days
e. 7 days

Answer

A

A - 24 hours

Question 36

Q

What is the minimum time following caesarean section that the indwelling catheter may be removed?

a. 6 hours
b. 10 hours
c. 12 hours
d. 24 hours
e. 48 hours

Answer

A

C - 12 hours

Question 37

Q

What proportion of women undergoing caesarean section will be affected by stress urinary incontinence?

a. 4%
b. 12%
c. 26%
d. 38%
e. 54%

Question 38

Q

A primigravida has a forceps delivery in theatre and shoulder dystocia is diagnosed requiring internal rotational manoeuvres to deliver the fetal trunk. When compared with the general obstetric population, what is this patient’s risk of recurrence of shoulder dystocia?

a. Equivalent risk
b. Five times higher
c. 10 times higher
d. 20 times higher
e. 30 times higher

Answer

A

C - 10 times higher

Question 39

Q

A 28 year old woman with a past history of a third-degree tear was admitted in established labour and progressed well. She was in the second stage of labour and pushing well with good descent. Which one of the following would be most appropriate in preventing the recurrence of an obstetric anal sphincter injury?

a. Cold compress during the second stage
b. Mediolateral episiotomy 45 degrees from midline when perineum is distended
c. Mediolateral episiotomy 60 degrees from midline when perineum is distended
d. Perineal protection at crowning
e. Perineal massage in the antenatal period

Answer

A

D - Perineal protection at crowning

The evidence for protective effect of routine episiotomy is lacking. Where performed, this should be done at 60 degrees from the midline with the perineum at full distention.

Perineal protection at crowning can be protective, as can a warm (though not cold) compress. No differences were noted in perineal trauma rates with perineal massage.

Question 40

Q

A woman with a body mass index of 63 has a complicated labour and delivery and nearly dies. Which of the following causes of maternal mortality is independent of her BMI?

a. Amniotic fluid embolism
b. Anaesthetic complications
c. Pre-eclampsia
d. Sepsis
e. Venous thromboembolism

Answer

A

D - Sepsis

Though maternal mortality and morbidity are increased with obesity and in general get worse the more obese the woman is, this curiously does not seem to hold true for severe sepsis

Question 41

Q

You are about to perform an outlet ventouse delivery for a pathological CTG in the delivery room for a patient with no regional analgesia. You anticipate the possible need for an episiotomy and decide to infiltrate the perineum with local anaesthetic prior to delivery. What is the maximum volume of 1% lidocaine (not mixed with adrenaline) which can be administered to a patient who weighs 50kg?

a. 10ml
b. 15ml
c. 20ml
d. 25ml
e. 30ml

Answer

A

B - 15ml

3mg/kg (of 10mg/ml) lidocaine is the maximum dose. Signs of toxicity generally appear 1-5 minutes following injection though may be delayed up to one hour.

Classical symptoms of toxicity are related to the CNS and include:

Numbness of the tongue or metallic taste in the mouth
Dizziness
Light-headedness
Disorientation
Tinnitus
Problems focusing

Question 42

Q

A primigravida is planned for an elective caesarean section for major placenta praevia. You are completing her consent form. What do you advise her is the risk of massive obstetric haemorrhage associated with caesarean section for placenta praevia?

a. 5 in 100
b. 10 in 100
c. 20 in 100
d. 30 in 100
e. 50 in 100

Answer

A

C - 20 in 100

The risk of massive haemorrhage in praevia is 12x the norm

Question 43

Q

Prior to undertaking a ventouse extraction delivery in a woman with no regional analgesia, you apply a pudendal block. What are the three branches of the pudendal nerve?

a. Inferior rectal, perineal, dorsal nerve of the clitoris
b. Inferior rectal, superior rectal, perineal
c. Perineal, dorsal nerve of the clitoris, ilioinguinal
d. Perineal, ilioinguinal, inferior gluteal
e. Perineal, inferior rectal, superior gluteal

Answer

A

A - Inferior rectal, perineal, dorsal nerve of the clitoris

Question 44

Q

Which of the following is NOT a recognised means of reducing the likelihood of requiring instrumental delivery?

a. Upright positioning in labour
b. Continuous support in labour
c. Avoidance of regional analgesia
d. Partogram use
e. Passive second stage in primigravidae with regional anaesthesia

Answer

A

D - Partogram use

There is no evidence that use of a partogram in labour reduces the likelihood of requiring instrumental delivery. Adopting an upright or lateral position, avoiding regional analgesia, a passive second stage in those with regional analgesia and continuous support in labour (particularly when the supporter is not a member of staff) all have been shown to be of benefit in this reducing the risk.

Question 45

Q

What is the minimum gestation at which vacuum delivery may be considered?

a. 32/40
b. 33/40
c. 34/40
d. 35/40
e. 36/40

Answer

A

C - 34/40

Vacuum delivery is contraindicated prior to 34/40 (owing to the susceptibility of the preterm infant to cephalohaematoma, intracranial haemorrhage, subgaleal haemorrhage and neonatal jaundice) and should be used with caution between 34 and 36/40 as there is insufficient evidence to support safety at these gestations.

Question 46

Q

Which of the following factors is NOT recognised as being associated with a higher rate of failure of instrumental delivery?

a. Maternal age >40
b. BMI >30
c. EFW >4000g
d. OP position
e. Mid-cavity delivery

Answer

A

A - Maternal age >40

Maternal BMI, estimated fetal weight, fetal malposition and descent of the presenting part all have a bearing on the likelihood of instrumental delivery being successful. There is no evidence that maternal age influences success.

Question 47

Q

Where regional analgesia is used for instrumental delivery, how long should an indwelling catheter remain in situ postnatally (minimum)?

a. Until fully mobile regardless of time
b. 6 hours
c. 12 hours
d. 18 hours
e. 24 hours

Answer

A

C - 12 hours

Operative delivery, prolonged labour and epidural analgesia all may predispose to postpartum urinary retention, which can be associated with long-term bladder dysfunction. Women who have had a spinal anaesthetic or an epidural that has been topped up for a trial should be offered an indwelling catheter for at least 12 hours post-delivery to prevent asymptomatic bladder overfilling followed by fluid balance charts to ensure good voiding volumes. The first void following removal should be noted and a PVR done if retention is suspected.

Question 48

Q

Who should debrief the patient on any operative vaginal delivery prior to discharge home?

a. Midwife on post-natal ward
b. SHO on post-natal ward
c. Named consultant obstetrician in charge of care
d. Obstetrician who performed delivery
e. Senior midwife on post-natal ward

Answer

A

D - The obstetrician who performed the delivery

Women should be debriefed prior to discharge from hospital on why instrumental delivery was necessary, on any complications and future prognosis. Best practice dictates that this should be done by the obstetrician who performed the delivery.

Question 49

Q

You review a patient on the post-natal ward who underwent a mid-cavity forceps delivery in theatre the previous afternoon for prolonged second stage. She asks about the likelihood of her requiring an instrumental delivery again in her next pregnancy. What percentage of women will go on to achieve spontaneous vaginal birth in a subsequent pregnancy after one instrumental delivery?

a. 55%
b. 60%
c. 75%
d. 80%
e. 85%

Answer

A

D - 80%

The aim for women who experience an instrumental delivery should be for spontaneous vaginal delivery in their subsequent pregnancy – 80% of such women achieve this.

Question 50

Q

A primigravida is taken to theatre for a trial of instrumental delivery for suspicious CTG following an induction of labour for suspected fetal macrosomia at 39/40. Examination in theatre is as follows: 0/5 per abdomen, fully dilated, DOA position, spines +2 station, caput +1, no moulding. A successful ventouse extraction is performed. How would this delivery be classified?

a. Lift-out
b. Outlet
c. Low
d. Mid-cavity
e. High

Answer

A

C - Low

The ACOG classification of operative vaginal delivery is referenced in the RCOG guideline for reference. Based on station of the presenting part alone:
• Above spines – high (OVD not recommended)
• At or below spines, above +2 – mid-cavity
• +2 below spines – low
• +3 below spines; head visible without parting the labia – outlet
‘Life-out’ is not a term in any formal classification of instrumental delivery.

Question 51

Q

A Para 1 is taken to theatre for a trial of instrumental delivery for prolonged second stage. Examination in theatre is as follows: 1/5 per abdomen, fully dilated, DOP position, at spines, caput +++, moulding ++. The registrar attempts 3 pulls with Neville Barnes forceps though there is suboptimal descent and opts to perform a caesarean section. What is the classification of this attempted instrumental delivery?

a. Outlet
b. Low
c. Mid-cavity
d. High
e. Outwith classification – instrumental delivery should not be attempted here

Answer

A

C - Mid-cavity

The scenario here describes an attempted mid-cavity delivery. Only 1/5 of the fetal head is palpable per abdomen which is the requisite threshold for consideration of instrumental delivery (instrumental should not be attempted where 2/5 or more is palpable) however a number of factors here suggest a low likelihood of success – malposition, a high head and signs suggestive of obstruction (caput and moulding) after a prolonged second stage in a multipara. Nevertheless there are no features in the history which suggest an attempt at instrumental delivery is absolutely contraindicated.

Question 52

Q

Which of the following complications occurs with equivalent frequency in both vacuum and forceps delivery?

a. Need for phototherapy
b. Retinal haemorrhage
c. Cephalohaematoma
d. Significant perineal trauma
e. Procedural failure

Answer

A

A - Need for phototherapy

When compared with forceps delivery, vacuum extraction is associated with an increased likelihood of failure (though curiously there is no difference in caesarean section rates); cephalohaematoma, retinal haemorrhage and maternal anxiety about the baby. The lower risk of maternal perineal trauma is an advantage of vacuum extraction over forceps. Need for phototherapy, caesarean section and 5-minute APGAR scores are equivalent for both modalities.

Question 53

Q

Which of the following complications of instrumental delivery is NOT an indication for completing an ‘incident report’ after the procedure?

a. pH <7.1
b. Unexpected admission to NICU
c. APGAR score <7 at 5 minutes
d. Birth trauma
e. Use of two instruments

Answer

A

E - Use of two instruments

The use of sequential instruments – while associated with a significant increased risk of fetal/neonatal injury – is not an indication for completion of an incident report. Where the first choice instrument has failed, the operator must then make a choice between the relative safety and likelihood of success with another instrument versus the risks of a second stage caesarean section, which may well be complicated further by the recent OVD attempt.

Question 54

Q

The use of multiple instruments is a known risk factor for neonatal trauma in operative vaginal delivery. What is the increased risk of neonatal intracranial or subdural haemorrhage in such an instance?

a. 2-3x
b. 4-5x
c. 6-7x
d. 9-10x
e. 15x

Answer

A

A - 2-3x

The risk of neonatal injury with forceps (1 in 860), vacuum (1 in 664) and intrapartum caesarean (1 in 954) is fairly similar. The risk with use of sequential instruments however is increased 2-3 fold (1 in 256).

Question 55

Q

Which of the following is not a recognised risk factor for should dystocia?

a. Maternal diabetes
b. Induction of labour
c. Maternal BMI <18
d. Maternal BMI >30
e. Assisted vaginal delivery

Answer

A

C - Maternal BMI <18

A number of risk factors – both ante- and intra-partum are known to be associated with shoulder dystocia though both singly and in combination, their predictive value is low – only 16% of shoulder dystocia resulting in infant morbidity could have been predicted by conventional risk factors. The main risk factors are as follows:

Pre-Labour:
Previous shoulder dystocia
Macrosomia >4.5kg
Diabetes 
BMI >30
Induction of labour

Intrapartum:
Prolonged first stage
Secondary arrest
Prolonged second stage
Oxytocin augmentation
Assisted vaginal delivery

Question 56

Q

What proportion of shoulder dystocia occurs in infants <4kg?

a. ~1/3
b. ~1/2
c. ~1/4
d. ~2/3
e. ~3/4

Answer

A

B - 1/2

While a relationship between fetal size and shoulder dystocia is recognised, it is not a good predictor – the vast majority of infants >4.5kg do NOT develop shoulder dystocia. Furthermore, 48% of should dystocia occurs in infants smaller than 4kg.

Question 57

Q

A newborn infant is reviewed on the post-natal ward round following a forceps delivery complicated by shoulder dystocia. His mother is concerned about the position in which he is holding his arm. What percentage of brachial plexus injuries sustained at the time of shoulder dystocia cause permanent neurological impairment?

a. 5%
b. 10%
c. 20%
d. 40%
e. 60%

Answer

A

B - 10%

Brachial plexus injury is one of the most important fetal consequences of shoulder dystocia. This is seen in up to 16% though with permanent neurological impairment in only 10% of those affected by BPI. There is some evidence to suggest that larger infants are more likely to be affected by BPI where shoulder dystocia occurs.

Question 58

Q

Relative to background risk, what is the risk of recurrence of shoulder dystocia?

a. 2x
b. 5x
c. 6x
d. 8x
e. 10x

Answer

A

E - 10x

Those with a history of previous should dystocia are thought to be at an increased risk of the complication occurring again – approximately 10x higher than the background risk. Overall recurrence risks are quoted as high as 25% although this may be infact an underestimate as many cases of severe shoulder dystocia lead to caesarean birth in subsequent pregnancies. There is no absolute requirement to recommended elective caesarean birth in a future pregnancy though either this or vaginal delivery is appropriate depending on maternal preference.

Question 59

Q

What percentage of shoulder dystocia will be relieved by McRobert’s position alone?

a. 33%
b. 50%
c. 66%
d. 75%
e. 90%

Answer

A

E - 90%

McRobert’s manoeuvre – defined as flexion and adduction of the maternal hips to position the thighs on her abdomen – is an effective intervention in shoulder dystocia with success rates from this simple step alone reported as high as 90%. This works by straightening the lumbosacral angle, rotating the maternal pelvis towards the head and increasing the relative AP diameter of the pelvis.

Question 60

Q

Which of the following steps may help in relieving a shoulder dystocia without risking further injury to the fetus?

a. Maternal pushing during contractions
b. Fundal pressure
c. Axial traction of the fetal head
d. Downward traction of the fetal head
e. Maternal ‘upright’ positioning

Answer

A

C - Axial traction of the fetal head

Upon recognition of a shoulder dystocia, the mother should be laid flat and advised not to push as this may exacerbate the impaction. With the hips hyper-flexed, axial traction (downwards traction is strongly associated with brachial plexus injury) should be applied at the usual traction as a normal delivery to assess whether the shoulders have been released. Suprapubic pressure from the side behind the fetal back can aid the efficacy of McRobert’s to improve success rates by reducing the fetal bi-sacromial diameter and rotating the anterior shoulder forwards into the oblique. Fundal pressure should not be used.

Question 61

Q

What is the risk of PPH and OASIS with shoulder dystocia?

  PPH	OASIS

a. 11% 4%
b. 20% 3%
c. 4% 15%
d. 15% 8%
e. 5% 5%

Answer

A

A - PPH 11%; OASIS 4%

Clinicians should be alert to the possibility of secondary complications after a shoulder dystocia including PPH and OASIS which occur at rates of 11 and 3.8% respectively.

Question 62

Q

What is the approximate incidence of shoulder dystocia in vaginal birth?

a. ~0.2%
b. ~0.7%
c. ~1.3%
d. ~2.1%
e. ~3.5%

Answer

A

B - ~0.7%

There is a wide variation in the reported incidence of shoulder dystocia. Studies report incidences between 0.58% and 0.70%

Question 63

Q

A patient is reviewed in the diabetic clinic following a scan on which the fetal weight is estimated at 4.2kg. She enquires about her risk of complications during birth. Compared with non-diabetic mothers, what is the relative risk of shoulder dystocia in women with diabetes?

a. Equivalent risk
b. 2-4x
c. 6-8x
d. 10-12x
e. 15-18x

Answer

A

B - 2-4x

Infants of diabetic mothers have a two- to four-fold increased risk of shoulder dystocia compared with infants of the same birth weight born to non-diabetic mothers. Elective caesarean should be considered for pregnancies complicated by diabetes (either pre-existing or gestational) in which the EFW is >4.5kg. The NNT to prevent one permanent BPI is 443 vs. 3695 in the non-diabetic population. The ACOG recommend that fetuses >5kg regardless of diabetic status should prompt consideration of LSCS delivery.

Question 64

Q

A woman attends the antenatal clinic at 20/40 in her second pregnancy. Her first pregnancy ended in an emergency LSCS for fetal distress at 8cm. Her scan today has demonstrated normal fetal anatomy, though the placenta is noted to be low lying, completely covering the os. What is the likelihood of placenta accreta in such a history?

a. Up to 5%
b. Up to 10%
c. Up to 14%
d. Up to 19%
e. Up to 23%

Answer

A

C - Up to 14%

The Green Top Guideline advises of a 1%, 1.7% and 2.8% risk of placenta praevia after 1, 2 and 3 previous caesarean sections respectively. Where praevia occurs, the risk of accreta is up to 14% with 1 previous section, up to 40% with 2 and 67% with 5 or more.

Answer 61

A

D - Maternal BMI 16

Factors which increase the risk of uterine rupture in women with previous caesarean section undergoing VBAC are well described:
•	Delivery interval <12 months (contentious)
•	Post-maturity
•	Maternal age >40
•	Obesity
•	Low pre-labour Bishop’s score
•	Macrosomia
•	Reduced myometrial thickness on scan
•	Induction/augmentation of labour

Answer 62

A

C - 72-75%

Quoting women an individualised success chance for VBAC is challenging as there are typically numerous conflicting variables in each case. As per the Green Top Guideline however, women should be informed that the overall success rate of planned VBAC is 72-75%. As differences can be considerable between different centres, counselling on local statistics may also be considered.

Answer 63

A

B - 5%

The risk of anal sphincter injury in women undergoing VBAC is quoted at 5% - higher than the UK average of 2.9% - birthweight is the biggest predictor of this though the increased rates of instrumental delivery seen in a VBAC population (up to 39%) may in part account for this.

Answer 64

A

E - 40%

This question describes a rather specific scenario though it is one which appears verbatim in the Green Top Guideline – the hypothetical patient possesses several of the most frequently described factors known to reduce the likelihood of successful VBAC (obesity, induction, previous section for failure to progress in the first stage, no history of vaginal delivery) – where all of these factors are present, the likelihood of successful VBAC is 40%.

Answer 65

A

B - Early first stage

90% of all uterine rupture occurs in labour – most commonly in the early first stage (4-5cm).

Answer 66

A

B - 2-3x risk rupture; 1.5x risk of caesarean

Induction of labour is known to have a considerable impact on the risk of uterine rupture and of requiring emergency caesarean delivery in women attempting VBAC when compared with women in spontaneous labour. Risks of rupture are increased 2-3 fold (to approx.1.5%) while the risk of caesarean delivery is increased 1.5-fold. While use of oxytocin for induction of labour seems almost certain to increase the risk of rupture, studies which evaluate its use in labour fail to comment on the indication for it’s use which may be a factor. One case-control study suggests a 4-fold or greater increased risk with the use of higher dose (>20mU/min) Oxytocin during VBAC labour.

Answer 67

A

A - 5%

The risk of recurrence of uterine rupture in women labouring with such a history is quoted at 5% - unacceptably high to support a decision to attempt VBAC such as in the scenario here.

Answer 68

A

C - Up to 40%

The risk of both praevia and accreta is increased in patients with previous caesarean section. In a patient such as that described – confirmed praevia with 2 previous caesareans – the risk of this actually representing an accreta is potentially as high as 40%.

Answer 69

A

C - 1 in 10

As many as 10% of women planning elective repeat caesarean will labour in advance of their date for section. For this reason it is good practice to discuss and document a plan for delivery in the event of such an occurrence.

Answer 70

A

B - 0.5%

The overall risk of rupture in women with one previous caesarean is 0.5% or 1 in 200. Likely lower in spontaneous labour and known to be higher with induction.

Answer 71

A

C - Up to 33%

The rate of eventual hysterectomy has not been shown to be significantly different between patients undergoing ERCS and those attempting VBAC. Meta-analysis has shown however that in the context of uterine rupture, hysterectomy rates are quoted up to 33%.

Answer 72

A

D - Previous vaginal birth

Women attempting VBAC with a history of one previous caesarean section should be informed that previous vaginal birth is the singular greatest predictor of success and associated with a 85-90% chance of success. It is also associated with a decrease risk of uterine rupture.

Answer 73

A

C - Previous caesarean for failure to progress

Rates of VBAC success are lower amongst women in whom the primary caesarean was performed for labour dystocia compared with malpresentation or fetal distress. Maternal age <40, white ethnicity, BMI <30, gestation <40/40, EFW <4kg and greater maternal height are all thought to increase likelihood of success.

Answer 74

A

E - Abnormal CTG

All of the signs/symptoms described are associated with uterine rupture though not all signs are seen in every patient – infact the ‘classic triad’ of pain, bleeding and fetal heart abnormality may be seen together in as little as 10%. Abnormal CTG is the most consistent finding and is seen in up to 76% of uterine rupture. It is important to note that scar dehiscence may be asymptomatic in almost 50% of cases (by the guidelines, rupture is defined as ‘disruption of uterine muscle involving the serosa or extension into the bladder/broad ligament, while dehiscence is defined as disruption of muscle with intact uterine serosa).

Answer 75

A

D - 1 in 1000

TOG 2016

Answer 76

A

A - Peritoneal entry

Where bladder injury occurs at primary caesarean section, this is most likely to occur during peritoneal entry compared with repeat caesarean where this is more likely during bladder reflection

TOG 2016

Answer 77

A

B - Bladder refection prior to uterotomy

Where bladder injury occurs at primary caesarean section, this is most likely to occur during peritoneal entry compared with repeat caesarean where this is more likely during bladder reflection

TOG 2016

Answer 78

A

C - Dome

TOG 2016

Answer 79

A

C - Transection

Transection and ligation (or kinking) by a suture are the most common ureteric injuries seen at caesarean section

TOG 2016

Answer 80

A

B - During entry into the peritoneal cavity

In primary CS, most bladder injuries occur during peritoneal entry, while in repeat CS most occur during dissection of the bladder from the lower uterine section (i.e. raising the bladder flap).

TOG StratOG Resource

Answer 81

A

C - 9.3%

TOG 2018

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