[45] Operative Vaginal Delivery Flashcards
What is operative vaginal delivery?
The use of an instrument to aid the delivery of the fetus
What % of deliveries in the UK are operative?
12-13%
What are the two main types of instruments used in operative vaginal delivery?
- Ventouse
- Forceps
Which instrument is most likely to succeed in delivering the baby vaginally?
The one that is used first - the one used second is less likely to deliver regardless which is used first
Which instrument has a lower risk of fetal complications?
Forceps
Which instrument has a lower risk of maternal complications?
Ventouse
When should an attempt to deliver with an instrument be abandoned?
After 3 contractions and pulls and no reasonable progress
What is a ventouse?
An instrument that attaches a cup to the fetal head via a vacuum
What are the most common types of ventouse?
- Electrical pump attached to a silastic cup
- Hand-held, disposable device commonly known as the Kiwi
When is an electrical pump ventouse suitable?
Only if the fetus is in an occipital-anterior position
When is a kiwi ventouse suitable? 🥝
All fetal positions and rotational deliveries
How is the ventouse used?
Cup is applied with centre over the flexion point of the fetal skull. Traction is applied perpendicular to the cup during contractions
What is the flexion point of the fetal skull?
In the midline 3cm anterior to the posterior fontanelle
What are the advantages of ventouse delivery?
- Less maternal perineal injuries
- Less pain
What are the disadvantages of ventouse delivery?
- Lower success rate
- More cephalohaematoma
- More subgaleal haematoma
- More fetal retinal haemorrhage
What are forceps (obstetrics)?
Double bladed instrument that comes in different types for different scenarios
What scenarios may require different forceps for delivery?
- OA positions
- C-section
- Rotational delivery
How are forceps used to deliver?
Introduced into the pelvis taking care not to cause trauma to maternal tissues and applied to fetal head with blades locked together. Gentle traction applied during contractions
What angle is used when applying traction to forceps?
Following the J shape of the maternal pelvis
What is the advantage of forceps delivery?
Don’t require maternal effort
What is the disadvantage of forceps delivery?
Have a higher rate of 3rd and 4th degree tears
When should a decision for operative vaginal delivery be made?
In the 2nd stage of labour
What are the main considerations when deciding on operational vaginal delivery?
- Is there a valid clinical indication
- Is the patient suitable
What are the most common maternal indications for operative vaginal delivery?
- Inadequate progress
- Maternal exhaustion
- Maternal medical conditions that mean active pushing should be limited
When should delivery be expected in nulliparous women?
After 2 hours of active pushing
When should additional time be allowed for pushing in nulliparous women?
If there is no urge to push at diagnosis of second stage (common in regional anaesthesia)
When should delivery be expected in multi-around women?
Within one hour of active pushing
What maternal medical conditions may limit active pushing in delivery?
- Intracranial pathologies
- Some maternal heart diseases
- Severe hypertension
What are some common fetal indications for operative vaginal delivery?
- Suspected fetal compromise in second stage of labour
- Clinical concerns e.g. significant antepartum haemorrhage
How are most fetal compromises diagnosed?
- CTG monitoring
- Abnormal fetal blood sampling
What are the pre requisites for operative vaginal delivery?
- Fully dilated
- Ruptured membranes
- Cephalic presentation
- Defined fetal position
- Fetal head at least the level of the ischial spines and no more than 1/5 palpable per abdomen
- Empty bladder
- Adequate pain relief
- Adequate maternal pelvis
What are some absolute contraindications to operative vaginal delivery?
- Unengaged fetal head in singleton pregnancy
- Incompletely dilated cervix in singleton
- True cephalo-pelvic disproportion
- Breech and face presentation
- Most brow presentation
What is true cephalo-pelvic disproportion?
Where the fetal head is too large to pass through the maternal pelvis
What are some specific absolute contraindications for ventouse delivery?
- Preterm gestation (<34 weeks)
- High likelihood of any fetal coagulation disorder
What are some relative contraindications for operative vaginal delivery?
- Severe non-reassuring fetal status and scalp is not visible
- Delivery of the second twin when head not quite engaged
- Prolapse of umbilical cord with fetal compromise when cervix is completely dilated and the station is mid cavity
How are operative vaginal deliveries classified?
By the degree of fetal descent
What are the classifications of operative vaginal delivery?
- Outlet
- Low
- Midline
How does the risk of complications change with classification of operative vaginal delivery?
Decreases the lower the classification
What is an outlet operative vaginal delivery?
- Fetal scalp visible with labia parted OR
- Fetal skull reached pelvic floor OR
- Fetal head on perineum
What is a low operative vaginal delivery?
Lowest presenting part (not caput) is +2 or further below the ischial spines
What is a low operative vaginal delivery subdivided into?
- > 45 degrees (rotation needed)
- <45 degrees (no rotation needed)
What is a midline operative vaginal delivery?
- 1/5 palpable abdominal
- Lowest part is above +2 but is lower than the ischial spines
What is a midline operative vaginal delivery subdivided into?
- > 45˚ - rotation needed
- <45˚ - no rotation needed
What are the potential fetal complications of operative vaginal delivery?
- Neonatal jaundice
- Scalp lacerations
- Cephalhaematoma
- Subgaleal haematoma
- Facial bruising
- Facial nerve damage
- Skull fractures
- Retinal haemorrhage
What are the potential maternal complications of operative vaginal delivery?
- Vaginal tears
- VTE
- Incontinence
- PPH
- Shoulder dystocia
- Infection
What are the 3rd/4th degree vaginal tear rates in a normal vaginal delivery?
1/100
What are the 3rd/4th degree vaginal tear rates in a ventouse delivery?
4/100
What are the 3rd/4th degree vaginal tear rates in a forceps delivery?
10/100
When is a lower complication rate likely in an operative vaginal delivery?
- Lower classification
- Less rotation needed
- Fewer pulls
