Assisted Vaginal Birth GTG

Question 1

What % of women delivery by assisted vaginal delivery?

Answer 1

10-15%

Question 2

What % of primips delivery by assisted vaginal delivery?

Answer 2

33% (lower in MW led units)

Question 3

What can reduce the risk of assisted birth?

Answer 3

Continous support

If epidural and P0, delay pushing for 1-2 hours

Question 4

Do epidurals increase risk of instrumental delivery?

Answer 4

Yes (less significant with new epidurals)

No difference in latent or ascot phase

No evidence reduced risk AVD if discontinue epidural in pushing phase

Question 5

What positions are recommended in labour if no epidural?

Answer 5

Upright/Lateral positions in 2nd stage

Question 6

What positions are recommended if epidural?

Answer 6

Lateral in 2nd stgage

Question 7

What is the definition of outlet assisted vaginal delivery?

Answer 7

Fetal scalp visible without separating the labia
Fetal head reached perineum
Rotation does not exceed 45 degree

Question 8

What is the definition of low assisted vaginal delivery? Rotational vs non rotational

Answer 8

Fetal scull is at 2+ but not at perineum

Non rotational equal to <45 degrees
Rotational > 45 degree

Question 9

What is the definition of mid assisted vaginal delivery?

Answer 9

Fetal head is no more than 1/5th palpable per abdomen

Leading point of skull is at 0 or +1 cm

Non rotational equal to <45 degrees
Rotational > 45 degree

Question 10

What are the fetal indications for AVD?

Answer 10

Suspected fetal compromise

Question 11

What are the maternal reasons for AVD

Answer 11

No progress after combination of active passive 2nd stage

P0
With epidural 3 hrs
Without epidural 2hrs

Multip
With epidural 2hrs
Without epidural 1hr

Maternal exhaustion
Medical indication - avoid valsalva

Question 12

When are vacuum cups contraindicated?

Answer 12

Avoid <32 weeks
Caution 32-36 weeks

Caution with suspected bleeding disorder/ predisposition to fracuture

Face presentation

Question 13

What safety criteria from examination must be fulfilled before AVD

Answer 13

Head equal or less than 1/5th palpable
Cx fully dilated and membranes rupture
At level or below ischial spines
position of fetal head determined
Caput and moulding less than 2+
Pelvis is deemed adequate

Question 14

What preparation of mother must occur before assisted vaginal delivery

Answer 14

Clear explanations and informed consent
Appropriate analgesia
Maternal bladder emptied
Catheter balloon removed and catheter removed
Aseptic

Question 15

Preparations for stafff

Answer 15

Operator has knowledge
Adequate facility
Back up plan for mid pelvic births e.g. theatres
Anticipation of complications
Person trained in neonatal rhesus stations

Question 16

If considering midpelvic or rotational delivery, what should be explained to the patient?

Answer 16

Risks & benefits of ASV or 2nd stage EMCS

EMCS - increased NNU admission and PPH

AVD - higer pelvic floor morbidity/neonatal trauma, more likely to have VD in next delivery (80% vs 305%)

Question 17

Which cases are considered high risk and should be taken to theatre?

Answer 17

BMI >30
Short maternal state
EFW>4kg
HC >95th
OP position
Midpelvic birth or 1/5th palpable

No sig difference in fetal outcomes

Question 18

Which has higher failure rate between vacuum and forceps, what is the failure rate

Answer 18

Vacuum more likely to fail (OR 1.7)
17-36% fail

Question 19

Vacuum cup is more likely too…

Answer 19

Fail
Cephalhaemotoma
Retinal haemorrhage
Maternal worries about the baby

Question 20

Forceps is more likely too….

Answer 20

Significant maternal perineal and vaginal trauma

No difference in bowel and bladder dysfunction at 5 years

Question 21

What significantly increases risk of subdural/cerebral haemorrhage

Answer 21

Change of instrument Change 1/256
forceps 1/664
Vacuum 1/860

Question 22

What is the risk of episiotomy
i) Vacuum
ii) Forceps

Answer 22

50-60%

90%

Question 23

What is the risk of OSAI
i) Vacuum
ii) Forceps

Answer 23

1-4%

8-12%

Question 24

What is the risk of significant vaginal/vulval tear
i) Vacuum
ii) Forceps

Answer 24

i) 1/10
ii) 1/5

Question 25

What is the risk of PPH
i) Vacuum
ii) Forceps

Answer 25

Same 10-40%

Question 26

What is the risk of cephalhaematoma
i) Vacuum
ii) Forceps

Answer 26

1-12%

Minimal

Question 27

Risk facial laceration

Answer 27

10% for both

Question 28

Risk retinal haemorrhage

Answer 28

17-38% for both

Question 29

Risk of jaundice

Answer 29

5-15%

Question 30

Subgleal haemorrhage

Answer 30

3-6/1000 for both

Question 31

Risk intracranial bleed

Answer 31

5-15/10,0000

Question 32

Additional procedures to consent for?

Answer 32

Episiotomy, manoeuvres shoulder dystocia, CS , blood transfusion, repair perineal teal, manual rotation before instrumental

Question 33

Maximum number of pulls for instrumental?

Answer 33

3 pulls to perineum
3 pulls out

If after 2 pulls, minimum descent, consider application, position, CP disproportion, second opinion

Question 34

After how many pop offs should the vacuum be discontinued?

Answer 34

2 pop offs

Question 35

Risk of OASI with sequential instruments?

Answer 35

17%

Question 36

When should forceps be stopped?

Answer 36

Not applied easily/locked
Lack descent with moderate traction
No imminent following 3 pulls

Question 37

When should episiotomy be given, what angle?

Answer 37

When head distending perineum
60 degrees

Question 38

Why given single dose IV Co-amox?

Answer 38

Reduce risk of chorio from19 to 11%
Reduced risk perineal wound infection/pain/wound breakdown

Question 39

If successful AVD chances of vaginal in next pregnancy?

Answer 39

90%

Question 40

Transverse and AP diameter of pelvic inlet?

Answer 40

Transverse 13 cm
AP 11cm

Question 41

Transverse and AP diameter of mid pelvis

Answer 41

transverse and AP 11cm

Question 42

Transverse and AP of pelvic outlet

Answer 42

transverse 11cm
AP 12.5cm