Assisted Vaginal Birth GTG Flashcards
What % of women delivery by assisted vaginal delivery?
10-15%
What % of primips delivery by assisted vaginal delivery?
33% (lower in MW led units)
What can reduce the risk of assisted birth?
Continous support
If epidural and P0, delay pushing for 1-2 hours
Do epidurals increase risk of instrumental delivery?
Yes (less significant with new epidurals)
No difference in latent or ascot phase
No evidence reduced risk AVD if discontinue epidural in pushing phase
What positions are recommended in labour if no epidural?
Upright/Lateral positions in 2nd stage
What positions are recommended if epidural?
Lateral in 2nd stgage
What is the definition of outlet assisted vaginal delivery?
Fetal scalp visible without separating the labia
Fetal head reached perineum
Rotation does not exceed 45 degree
What is the definition of low assisted vaginal delivery? Rotational vs non rotational
Fetal scull is at 2+ but not at perineum
Non rotational equal to <45 degrees
Rotational > 45 degree
What is the definition of mid assisted vaginal delivery?
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
What are the fetal indications for AVD?
Suspected fetal compromise
What are the maternal reasons for AVD
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
When are vacuum cups contraindicated?
Avoid <32 weeks
Caution 32-36 weeks
Caution with suspected bleeding disorder/ predisposition to fracuture
Face presentation
What safety criteria from examination must be fulfilled before AVD
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
What preparation of mother must occur before assisted vaginal delivery
Clear explanations and informed consent
Appropriate analgesia
Maternal bladder emptied
Catheter balloon removed and catheter removed
Aseptic
Preparations for stafff
Operator has knowledge
Adequate facility
Back up plan for mid pelvic births e.g. theatres
Anticipation of complications
Person trained in neonatal rhesus stations
If considering midpelvic or rotational delivery, what should be explained to the patient?
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%)
Which cases are considered high risk and should be taken to theatre?
BMI >30
Short maternal state
EFW>4kg
HC >95th
OP position
Midpelvic birth or 1/5th palpable
No sig difference in fetal outcomes
Which has higher failure rate between vacuum and forceps, what is the failure rate
Vacuum more likely to fail (OR 1.7)
17-36% fail
Vacuum cup is more likely too…
Fail
Cephalhaemotoma
Retinal haemorrhage
Maternal worries about the baby
Forceps is more likely too….
Significant maternal perineal and vaginal trauma
No difference in bowel and bladder dysfunction at 5 years
What significantly increases risk of subdural/cerebral haemorrhage
Change of instrument Change 1/256
forceps 1/664
Vacuum 1/860
What is the risk of episiotomy
i) Vacuum
ii) Forceps
50-60%
90%
What is the risk of OSAI
i) Vacuum
ii) Forceps
1-4%
8-12%
What is the risk of significant vaginal/vulval tear
i) Vacuum
ii) Forceps
i) 1/10
ii) 1/5
What is the risk of PPH
i) Vacuum
ii) Forceps
Same 10-40%
What is the risk of cephalhaematoma
i) Vacuum
ii) Forceps
1-12%
Minimal
Risk facial laceration
10% for both
Risk retinal haemorrhage
17-38% for both
Risk of jaundice
5-15%
Subgleal haemorrhage
3-6/1000 for both
Risk intracranial bleed
5-15/10,0000
Additional procedures to consent for?
Episiotomy, manoeuvres shoulder dystocia, CS , blood transfusion, repair perineal teal, manual rotation before instrumental
Maximum number of pulls for instrumental?
3 pulls to perineum
3 pulls out
If after 2 pulls, minimum descent, consider application, position, CP disproportion, second opinion
After how many pop offs should the vacuum be discontinued?
2 pop offs
Risk of OASI with sequential instruments?
17%
When should forceps be stopped?
Not applied easily/locked
Lack descent with moderate traction
No imminent following 3 pulls
When should episiotomy be given, what angle?
When head distending perineum
60 degrees
Why given single dose IV Co-amox?
Reduce risk of chorio from19 to 11%
Reduced risk perineal wound infection/pain/wound breakdown
If successful AVD chances of vaginal in next pregnancy?
90%
Transverse and AP diameter of pelvic inlet?
Transverse 13 cm
AP 11cm
Transverse and AP diameter of mid pelvis
transverse and AP 11cm
Transverse and AP of pelvic outlet
transverse 11cm
AP 12.5cm
