Instrumental

Question 1

Postnatal care involvement

Answer 1

Analgesia
Voiding function
Bowel function
Thromboembolic prophylaxis
Rehabilitation of the pelvic floor
Counselling regarding the birth and future births

Question 2

Percentage of births

Answer 2

11% aus

10% nz

Question 3

Likelihood of vaginal birth after one previous

Answer 3

78-91%

Question 4

Consequences of delays in second stage of labour

Answer 4

Increased chance of fetal compromise with prolonged pushing in second stage, or when the presenting part Is low on the perineum for an extended length of time
Maternal exhaustion
Pelvic floor injury

Question 5

Relative contraindications and contraindications to instrumental birth

Answer 5

Fetal bleeding disorders
Predispostion to fractures

No vacuum for a face presentation or <34/40
Caution ventouse 34-36

Question 6

Prerequisites for instrumental vaginal birth

Answer 6

Full abdominal and VE: less than or equal to 1/5 palpable abdominal Ly, head, fully dilated, ROM, position, assess caput and mounding, pelvis adequate

Prep mother: explanation, consent, analgesia, bladder emptied, aseptic technique

Prep staff: operated needs knowledge, experience and skill, adequate facilities, back up plan, anticipate complications, neonatal resus team

Question 7

Outlet birth

Answer 7

Fetal scalp visible without separating labia
Fetal skull reached the pelvic floor
Sag suture in AP diameter or ROA or LOA or OP (do not exceed rotation >45 degrees)
Fetal head is at or on perineum

Question 8

Low

Answer 8

Leading point of the skull (not caput) is at station plus 2cm or more and not on the pelvic floor
Rotation of 45 degrees or less from the OA
Rotation of more than 45 degrees including the OP position

Question 9

Mid

Answer 9

Fetal head is no more than 1/5th palp
Leading point of the skull is above station +2cm but not above the ischial spines

Subdivisions

• rotation of 45 degrees or less from the OA position
• rotation of more than 45 degrees including OP

Question 10

High

Answer 10

Not included in the classification as instrumental vaginal birth is not recommended in this situation where the head is 2/5th or more palpable abdominal Ly and the presenting part is above the level of the ischial spines

Question 11

Increased risk of instrumental failure

Answer 11

BMI>30
EFW >4kg
OP
Mid cavity or when 1/5 palp abdominally

Question 12

Cup placement

Answer 12

Flexion point (6cm from the anterior fontanelle and 3cm from the posterior fontanelle in the midline over the Sagital suture)

Question 13

Failure rate and scalp injury rates by cups

Answer 13

Failure:
Rigid 9.5
Soft 14.8

Injury
Rigid 24%
Soft 13%

Question 14

Vacuum suction pressures

Answer 14

500-600mmHg

Establishment of negative pressure without delay reduces procedure time without compromising effectiveness or safety

Question 15

Rotational forceps risks over caeser

Answer 15

Increased risk of traumatic intracranial haemorrhage and cervical spine injury

Question 16

Rotational cup risks

Answer 16

Higher failure rate

Increased risk intracranial and subaponeurotic/subgaleal haemorrhage

Question 17

Complications of instrumental birth (fetal)

Answer 17

Shoulder dystocia
Subgaleal haemorrhage
Facial nerve palsy
Corneal abrasion
Retinal haemorrhage
Skull fracture
ICH
Cervical spine injury

Question 18

Risk of skull fracture and or intracranial haemorrhage by mode of birth

Answer 18

Forceps : 1 in 664
Vacuum: 1 in 860
Caeser (intrapartum): 1 in 907
SVB: 1 in 1900
Cold caeser: 1 in 2750

Question 19

Maternal complications of instrumental del

Answer 19

Vaginal trauma
PPH
urinary tract injury
Damage to pelvic floor 
Damage to anal sphincter

Question 20

Advantage forceps

Answer 20

More likely to achieve vaginal birth
Less cephalhaematoma
Less fetal retinal haemorrhage
Less neonatal jaundice
Less shoulder dystocia
Less maternal worry

Question 21

Advantage vacuum

Answer 21

Less OASIS
Less type of any vag trauma
Less incontinence

Question 22

No significant difference between instruments

Answer 22

Any neonatal injury
Low apgar score (<7) at 5 minutes
Low pH (<7.2) in umbilical artery at birth

Question 23

Subgaleal haemorrhage

Answer 23

Accumulation of blood in the loose connective tissue of the subgaleal space

Question 24

Rate of mortality with SGH

Answer 24

12-25%

Question 25

Risk factors for SGH

Answer 25

Vacuum extraction
Incorrect positioning
Prolonged extraction time (>20min)
>3pulls 
>2 cup detachments
Failed vacuum
PROM >12 hours
Macrosomia, neonatal coagulopathy
LBW
male sex

Nulliparity
5 minute apgar <8
Cup marks on sagital suture
Leading edge of cup <3cms from anterior fontanelle

Question 26

Pathophysiology of SGH

Answer 26

Fractional and rotational forces with the use of vacuum extraction can result in rupture of veins and haemorrrhage into different layers of the scalp.
Most significant - rupture of emissary veins into the subgaleal space

Question 27

Signs of SGH

Answer 27

Generalized swelling or a boggy consistency of the scalp, not limited by sutures, especially at the cut site
Elevation and displacement of the ear lobes and periorbital oedema
Hypovolemic shock:tachycardia, tachypnoea, dropping haematocrit on blood gases, increasing lactates, worsening acidosis, poor activity, pallor , hypotension, acidosis

Question 28

Degree of SGH

Answer 28

6% asymptomatic
15-20% mild
40-50% moderate
25-335 severe

Question 29

Management SGH

Answer 29

Vit K asap
Cord ph, lactate, FBC and platelets
Admit nicu for Obs
Coag
Group and cross matched
Cap gas
Maintain bsls

Question 30

Indications for operative vaginal delivery

Answer 30

Presumed fetal compromise
To shorten and reduce the effects of the second stage of labour on medical conditions (ie cardiac disease)
Inadequate progress -
-primip: lack of continuing progress for 3 hours (total of active and passive second stage labour) with regional anaesthesia or 2 hours without regional anaesthesia
-multip- lack of progress for 2 hours with anaesthesia or 1 hour without
Maternal exhaustion