Management of Labour and Delivery including GT26 Operative Vaginal Delivery, GT29 3rd/4th Perineal Tears, GT42 Shoulder Dystocia Flashcards
How much above background risk is the chance of a shoulder dystocia if a woman has had one previously?
x10
Background risk is 1 in 150
What is the incidence of breech presentation at term?
3-4%
What percentage of all live births were <37/40 in England and Wales in 2005?
7.6%
What is the mortality rate for babies born
@23/40?
@32/40?
23/40 >90%
32/40 2%
What is the incidence of 3rd/4th degree perineal tears associated with Shoulder dystocia?
3.8%
Background incidence in
primp is 6.1%
Multip is 1.7%
What is the rate of recurrence of shoulder dystocia?
15-25%
What is the overall rate of OASIS in the UK and what measure decreases risk?
3%
Hands poised on perineum
What is the recurrence rate of placental abruption?
4.4% (OR 7.8)
19-25% after 2 abruptions
What is the rate of dural headache followin accidental dural puncture and when do 90% develop by?
70%
within 3 days
What is the sensory supply to the uterus and cervix?
T11-L1 uterine via Frankenhauser’s plexus
Cervical dilatation perceived at T11-12
What are the UK rates of operative vaginal delivery?
10-13%
What are the measures to help avoid operative vaginal delivery?
- Continuous support during labour (RR 0.82)
- Upright/lateral positions, (RR 0.80)
- Avoiding epirdural (OR 1.4 more likely to have OVD)
- Delayed pushing in primips with epidural - decreased rotational/midcavity OVD
What are the gestational limits of vacuum extraction?
34/40
Safety unknown, insufficient evidence 34-36+0/40
What risk factors contribute to a high failure rate for OVD?
- BMI >30
- EFW >4kg/clinically big baby
- OP position
- Mid cavity
What are the differences between outcomes with soft and rigid ventouse cups?
- Increase failure rate OR 1.6
- Less puerperal scalp trauma OR 0.4
What is the failure rate with Kiwi OmniCup?
13%
What is more likely with vacuum vs forceps…?
- Cephalhaematoma OR 2.4
- Maternal worries about baby OR 2.2
- Retinal haemorrhage OR 2.0
- Failed delivery OR 1.7
What is less likely with vacuum vs forceps…?
Significant maternal perineal and vaginal trauma OR 0.4
What is no more likely with vacuum vs forceps…?
- Delivery by CS
- 5 min Apgar scores being low
- Need for phototherapy
What % of women will have spontaneous VB after OVB?
80% even if complex instrumental in theatre
What is the incidence of OASI in the UK?
2.9% (Range 0-8)
6% Pri, 1.7% Multip
Tripled from 2-6% from 2000-2012
What are the risk factors for OASI?
- Nullip (OR 6.97)
- OP position (2.44)
- Asian (2.27)
- BW >4kg (2.27)
- Shoulder dystocia (1.90)
- Prolonged second stage (RR 2 if >4hrs)
- Instrumental delivery - forceps no epis OR 6.5
- Recurrent (5.51 - even higher if above RFs)
What are preventive measures for OASI?
- Consider RMLE
- Perineal protection at crowing
- Warm compression 2nd stage RR 0.48
- Perineal massage last 4/40 RR 0.91 of trauma requiring suturing
Which suture is recommended for the anorectal mucosa?
3.0 polyglactin, continuous or interrupted
Which sutures is recommended for the external anal sphincter?
3.0 PDS or 2.0 polyglactin
Overlapping or end to end
Bury under superficial perineal muscles
What is the incidence of suture migration in OASI?
7%
What is the risk of further 3rd/4th degree tear in subsequent pregnancies?
5-7%
17% will have worsening symptoms if they were symptomatic at 3-6 months postpartum
What is the incidence of shoulder dystocia?
0.58-0.70%
What % will have a PPH with shoulder dystocia?
11%
What % will have 3rd/4th degree tear with shoulder dystocia?
3.8%
What is the rate of brachial plexus injury with shoulder dystocia? And how many occurred after CS?
- How many with permanent neurological dysfunction?
- What % due to substandard care?
2-16% (0.43/1000)
At CS - 4%
Permanent dysfunction - <10%
Substandard - 46%
What % of shoulder dystocias are predicted by conventional risk factors?
16%
What are the pre-labour risk factors for shoulder dystocia?
- Previous shoulder dystocia
- Macrosomia >4.5kg
- DM (x2-4 risk)
- BMI >30
- IOL
What are the intrapartum risk factors for shoulder dystocia?
- Prolonged 1st stage
- Secondary arrest
- Prolonged 2nd stage
- Oxytocin augmentation
- Assisted vaginal delivery
When should IOL be considered for shoulder dystocia?
Term with women with GDM
Not for suspected macrosomia
When should elective Caesarean section be considered to prevent brachial plexus injuries?
In diabetic women regardless of treatment with EFW >4.5kg
NNT 443 vs 3695 (non-diabetic)
ACOG recommend consideration if EFW >5kg
What is the increase in risk of shoulder dystocia in someone with a previous history of shoulder dystocia?
10x that of general population
recurrence rate 1-25%
Which factors should be considered in women with previous shoulder dystocia when planning mode of delivery?
- Previous maternal or neonatal injury
- Predicted size
- Maternal choice
What is the incidence of humeral fractures with delivery of the posterior arm?
2-12%
What is the time cut off for hypoxic ischaemia in management of shoulder dystocia?
5 minutes
What are the maternal complications of shoulder dystocia?
- PPH
- 3rd/4th degree tears
- Vaginal/cervical lacerations
- Bladder rupture
- Uterine rupture
- Symphyseal separation
- SI joint dislocation
- Lateral femoral cutaneous nerve dysfunction
What are the fetal complications of shoulder dystocia?
- Brachial plexus injury (Erb’s C5-6; Clumpke’s C8-T1)
- Humeral and clavicular fracture
- Pneumothorax
- Brain damange
What is the incidence of cord prolapse?
0.1-0.6%
1% of breech babies
What is the mortality rate from cord prolapse?
91/1000
What is the rate of SVD following IOL with prostaglandins alone?
61-70%
How many births are there a year in England/Wales?
And what proportion are first babies and how many spontaneous labours?
700,000
40% first
2/3 spontaneous
90% cephalic singletons
What is the increase in risk of adverse outcome for baby with a homebirth in a low risk nullip compared to other birth settings?
4/1000
