Women's Health : Problems in Labour Flashcards
First Stage Delay in Labour Definition
cervical dilatation of less than 2cm in 4 hours.
Nulliparous Second Stage Delay
> 2 hour duration of second stage of labour.
Multiparous Second Stage Delay
> 1 hour duration of second stage of labour.
Actively Managed (oxytocin injection) Third Stage Delay
> 30 minutes without delivery of placenta
Physiological Third Stage Delay
> 60 minutes without delivery of placenta.
Three Ps’ of Delayed Labour
Power, Passenger, Passage
What is “Power” in relation to delayed labour?
Uterine contractions - deviation from normal (i.e. 3-5 contractions of 30 seconds duration per 10 minutes).
What is considered a deviation from normal uterine contractions?
3-5 contractions/30 sec/10 min
What are important factors related to the ‘Passenger’ in labor?
Size, presentation, position of the foetus
How is size of foetus monitored?
head diameter, shoulder diameter etc
How is foetal presentation monitored?
Cephalic:vertex, brow, face vs breech
How is foetal position monitored?
occipito-anterior (normal), occipito-posterior, occipito-transverse
What is the normal fetal position?
Occipito-anterior
What is “Passage” in relation to delayed labour?
Cephalopelvic disproporion
How are delays in labour investigated?
● Diagnosed by regular foetal monitoring in labour. ● Aberrant foetal position can be diagnosed on vaginal examination.
How is aberrant foetal position diagnosed?
Vaginal examination
What is the first stage in the management of delayed labour?
Membranes intact - consider amniotomy. ○ Consider oxytocin infusion - requires continuous foetal monitoring (CTG).
What is the second stage in the management of delayed labour?
Consider oxytocin infusion. ○ Offer expedited delivery i.e. instrumental delivery or caesarean section if vaginal delivery is improbable.
What is the third stage in the management of delayed labour?
Controlled cord traction, IM oxytocin / ergometrine.
What to consider if membranes are intact in the first stage?
Amniotomy
What is shoulder dystocia?
(RCOG) Vaginal cephalic delivery that requires additional obstetric manoeuvres to deliver the foetus after the head has delivered and gentle traction has failed.
What causes shoulder dystocia?
Discrepancy between size of foetal shoulders and maternal pelvic inlet leads to impaction: ○ Anterior shoulder behind maternal pubic symphysis (commonest). ○ Posterior shoulder behind maternal sacral promontory (more rare). ● Delay in delivery can result in hypoxic ischaemic encephalopathy (HIE) due to compression of the umbilical cord against the maternal pelvis. ● Another notable complication is brachial plexus injury resulting in Erb’s palsy (C5-6) or less commonly Klumpke’s palsy (C8-T1).
Where does the anterior shoulder get impacted?
Behind maternal pubic symphysis (commonest)
Where does the posterior shoulder get impacted?
Behind maternal sacral promontory (more rare)
What is Erb’s palsy?
C5-6 brachial plexus injury
Risk Factors for Shoulder Dystocia
- Previous shoulder dystocia 2. Macrosomia (foetal weight > 4500g) 3. Maternal diabetes mellitus 4. High maternal BMI 5. Induction of labour 6. Prolonged labour.
Signs of Shoulder Dystocia (which can lead to diagnosis)
○ Difficulty delivering face / chin ○ Turtle-neck sign (head retracts into birth canal) ○ Failure of restitution ○ Failure of shoulder descent
When can a definitive diagnosis of Shoulder Dystocia be made?
Definitive diagnosis is made when normal axial traction cannot deliver the baby’s body after the head has been delivered.
First Line Management for Shoulder Dystocia
- McRoberts’ manoeuvre (mother hyperflexes hips, bringing her thighs to her abdomen) plus
- Suprabupic pressure (to disimpact anterior shoulder) plus
- Discourage pushing (to prevent further impaction.
Second Line Management for Shoulder Dystocia
- Deliver posterior arm 2. Attempt internal rotation manoeuvres.
- If above fails - all fours position and repeat manoeuvres
Third Line Management (rare) for Shoulder Dystocia
○ Cleidotomy
○ Symphysiotomy
○ Zavanelli manoeuvre.
What does suprapubic pressure aim to do?
Disimpact anterior shoulder.
Why should pushing be discouraged during shoulder dystocia?
Prevent further impaction.
What to do if first line options fail?
All fours position, repeat manoeuvres
What is assisted vaginal birth (by forceps or vacuum) also known as?
Instrumental Delivery
How common are instrumental deliveries in the UK?
10-15% of deliveries ; ; ⅓ of first deliveries for nulliparous women.
What are the 2 types of instrumental delivery?
Forceps and Vacuum
What is typical for forceps delivery?
Interlocking blades fit around the baby’s head and guide it down the birth canal,
typically alongside medio-lateral episiotomy.
What is vacuum delivery?
Suction cup adheres to the baby’s head to assist with delivery
What is an outlet classification in assisted vaginal birth?
The fetal scalp is visible, the skull has reached the perineum, and the required rotation is less than 45 degrees.
What is a low cavity classification in assisted vaginal birth?
The fetal station is at +2 cm, but the skull has not yet reached the perineum.
What is a mid cavity classification in assisted vaginal birth?
The fetal head is less than 1/5th palpable abdominally, and the station is between +1 cm and 0 cm.
What type of instruments are used for non-rotational assisted deliveries?
Neville Barnes forceps (low cavity) : Simpson’s forceps
Wrigley forceps (outlet, also used in caesarean sections)
Anterior cup
What type of instruments are used for rotational assisted deliveries?
Kjelland’s forceps ; Posterior cup (e.g., Kiwi)
When are rotational instruments used in assisted vaginal deliveries?
Rotational instruments are used when the fetal position is occipito-posterior or occipito-transverse.
When are Wrigley forceps typically used?
Wrigley forceps are used for outlet deliveries and during caesarean sections
What classifies an outlet-assisted vaginal birth?
Visible scalp, <45° rotation.
What classifies a low cavity-assisted vaginal birth?
Station +2cm, not perineum.
What classifies a mid cavity-assisted vaginal birth?
Station +1 to 0cm.
When are rotational instruments used in assisted deliveries?
Occipito-posterior/transverse position.
Non-rotational forceps examples
Neville Barnes, Simpson’s, Wrigley
Rotational forceps example
Kjelland’s
Use of Wrigley forceps
Outlet, caesarean sections
Indications for Instrumental Delivery
- Suspected foetal compromise 2. Delayed second stage 3. Maternal exhaustion / distress 4. Medical contraindication to Valsalva
Risks of Forceps
- Vaginal trauma 2. Postpartum haemorrhage 3. Obstetric anal sphincter injury (3rd degree tear) 4. Facial / scalp laceration
Risks of Vacuum
- Vaginal trauma 2. Postpartum haemorrhage 3. OASI 4. Facial / scalp laceration 5. Retinal haemorrhage 6. Cephalohematoma 7. Subgaleal haemorrhage
How are obstectric injuries classified?
Degrees of Tears
1st Degree Tear
Skin only
2nd Degree Tear
Perineal muscle
3rd Degree Tear Types
Type A <50% external AS, Type B >50% external AS, Type C internal & external AS
4th Degree Tear
Anorectal epithelium
Caesarean Sections are categegorised by….
classifications of urgency
Category 1 Caesarean
within 30 minutes of decision - immediate threat to life of woman or foetus e.g. pathological CTG, placental abruption.
Category 2 Caesarean
within 75 minutes of decision - maternal / foetal compromise, not immediately life-threatening but birth must be expedited.
Category 3 Caesarean
no compromise, early birth indicated.
Category 4 Caesarean
elective
Indications for a Caesarean Section
-Breech presentation (resistant to external cephalic version).Placenta praevia
- Placenta accreta spectrum
- Maternal choice
- Emergency: foetal bradycardia, abruption, uterine rupture, cord prolapse, foetal pH <
7.20, failure of instrumental delivery.
