Labour & Delivery Flashcards
How are the trimesters split in pregnancy?
When does the 1st trimester begin and end?
Begins at 0 weeks, ends at 14
Ehrn ford 2nd trimester begin and end?
14 weeks, ends at 28 weeks
NOTE: 24 week is the point of viability
When is the point of viability of pregnancy?
24 weeks
When is antepartum?
24 weeks to Term
When does 3rd trimester begin and end?
28 weeks to 42 weeks
What is labour defined as?
ONSET OF SPONTANEOUS, REGULAR, PAINFUL CONTRACTIONS
What are braxton-hicks contractions?
false contractions that are benign
What is stage 1 of labour? How many phases are there?
From the onset of regular painful contractions
To full dilation of the cervix
2 phases
What are the 2 phases in stage 1 of labour?
Latent Phase: Until the cervix is 4 cm dilated
Active Phase: Until the cervix is fully dilated (10 cm)
What occurs in the latent phase of stage 1 of labour?
Latent Phase: Until the cervix is 4 cm dilated
NB: Followed by Active Phase: Until the cervix is fully dilated (10 cm)
What occurs in the active phase of stage 1of labour?
Active Phase: Until the cervix is fully dilated (10 cm)
NB: Preceded by Latent Phase: Until the cervix is 4 cm dilated
How to measure progress in stage 1 of labour?
Progress: Should be at least 1 cm dilation every 2 hours (any less than this is considered a prolonged first stage)
When should full effacement be reached in labour? what is effacement?
Effacement should be reached at end of latent phase of stage 1 of labour.
Effacement is when the cervix stetches, thins and softens.
How long can stage 1 of labour last?
Timescale: Can last up to 24 hours
When occurs during stage 2 of labour? How many phases?
From full dilation of the cervix
To delivery of the foetus
2 phases
What are the 2 phases of stage 2 of labour?
Passive Phase: No maternal effort
Active Phase: From the onset of the maternal urge to push
What occurs in the passive phase of stage 2 of labour?
Passive Phase: No maternal effort
NOTE: Followed by Active Phase: From the onset of the maternal urge to push
What occurs in the active phase of stage 2 of labour?
Active Phase: From the onset of the maternal urge to push
NOTE: Preceded by Passive Phase: No maternal effort
What is the timescale of stage 2 of labour?
Timescale: No longer than 3 hours in primiparous women and 2 hours in multiparous women
What can be used to augment uterine contractions in stage 2 of labour?
Syntocinon can be used to augment uterine contractions
NOTE: CTG monitoring should be commenced if the patient is receiving syntocinon
What should be monitored when on Syntocinon?
CTG
What might Syntocinon be given for? When?
Syntocinon can be used to augment uterine contractions
NB: GIven in stage 2 of labour
What is prolonged 2nd stage of labour classed as?
Nulliparous > 2 hours since onset of active 2nd stage
Multiparous > 1 hour since onset of active 2nd stage
Allow an extra hour if they have epidural analgesia
What is stage 3 of labour defined as? How many phases?
From delivery of the foetus
To delivery of the placenta
1 phase
Causes of prolonged labour
Powers: relates to the strength of the uterine contractions that aim to expel the foetus
Weak uterine contractions
Passage: relates to the ergonomics of the birth canal (e.g. dimensions of the pelvis, resistance of the perineum)
Tough perineum
Cephalopelvic disproportion
Passenger: relates to the size and diameters of the foetal head
Abnormal lie
What issues with power can cause prolonged labour?
Weak uterine contractions
What issues with passage can cause prolonged labour?
Tough perineum
Cephalopelvic disproportion
What issues with the passenger can cause prolonged labour?
Abnormal lie
3 main fundamental issues that can cause prolonged labour
Power, passage, passenger
2 types of delivery
Spontaneous vaginal delivery
Elective C-section
What may be trialled if difficulty starting labour?
Induction of labour
Prostaglandins (pessary/gel) or devices (balloon catheter) are used to dilate the cervix
What can be used to dilate the cervix if there is difficulty starting labour?
Prostaglandins (pessary/gel) or devices (balloon catheter) are used to dilate the cervix
What can be done if there is difficulty progressing in labour?
Augmentation of labour
Artificial rupture of the membranes -> natural release of prostaglandins
Synthetic oxytocin/syntocinon -> improve quality of contractions
What procedure may be done if difficulty progressing in labour?
Artificial rupture of the membranes -> natural release of prostaglandins
NB: assuming that membranes aren’t already ruptured
Why may artificial rupture of membranes be done if difficulty progressing in labour?
natural release of prostaglandins
What may be given adjunct to ARM if difficulty progressing labour?
Synthetic oxytocin/syntocinon -> improve quality of contractions
2 types of emergency delivery
Instrumental delivery (venthouse or forceps)
Emergency C-section
Examples of instrumental delivery
venthouse or forceps
What does presentation refer to in terms of labour?
Refers to the position of the baby’s head during labour
Types of presentation during labour
Vertex Presentation: The ideal position that presents the narrowest diameter of the head.
Brow Presentation: Neck is extended to ~90 degrees
Face Presentation: Neck is fully extended to ~120 degrees
NOTE: Refers to the position of the baby’s head during labour
Vertex presentation during labour
Vertex Presentation: The ideal position that presents the narrowest diameter of the head.
NOTE: Refers to the position of the baby’s head during labour
Brow presentation during labour
Brow Presentation: Neck is extended to ~90 degrees
NOTE: Refers to the position of the baby’s head during labour
Face presentation during labour
Face Presentation: Neck is fully extended to ~120 degrees
NOTE: Refers to the position of the baby’s head during labour
What does position refer to in labour?
Relates to orientation of the baby during deliver
What can the position be described as in terms of its longitudinal orientation?
Can be described as cephalic or breech based on the longitudinal orientation
What can be palpated in order to allow assessment of direction that the foetus is facing?
anterior fontanelle
What is the ideal presentation of baby for labour?
Vertex Presentation: The ideal position that presents the narrowest diameter of the head.
What is worst presentation of baby for labour?
Face Presentation: Neck is fully extended to ~120 degrees
What can the baby position of baby be described as based on direction foetus is facing?
Occipitoanterior (OA): Ideal orientation for delivery
Can be described as left or right OA if the orientation is slightly off centre
Occipitoposterior (OP)
Transverse: Least conducive with delivery
What orientation is best for dellivery?
Occipitoanterior (OA): Ideal orientation for delivery
What orientation is worst for delivery?
Transverse: Least conducive with delivery
What are the requirements for consideration of instrumental delivery?
Fully dilated cervix
Ruptured membranes
Cephalic presentation
Engaged presenting part (not palpable abdominally)
Comparison of venthouse and forceps delivery
Pros and cons of Venthouse delivery
- More baby complications e.g. cephalohaematoma, subgaleal haematoma
- Fewer maternal complications, less pain
- Lower success rate
Pros and cons of forceps delivery
- More maternal complications e.g. vaginal tears, incontinence
- Maternal effort not required
Neville-Barnes: OA deliveries
Kielland’s: rotational deliveries
What is shoulder dystocia?
Birth complication in which the shoulder gets stuck during delivery and that requires additional obstetric manoeuvres to deliver the fetus after the head has delivered and gentle traction has failed.
RFs for shoulder dystocia
Pre-labour:
Previous shoulder dystocia
Foetal macrosomia
Diabetes mellitus
Maternal obesity
Instrumental delivery
Intrapartum-
Prolonged labour
Oxytocin augmentation
Assisted vaginal delivery
Maternal complications of shoulder dystocia
Perineal Trauma
Postpartum Haemorrhage
Foetal complications of shoulder dystocia
Brachial Plexus Injury (e.g. Erb’s palsy)
Clavicle or Humerus Fracture
Hypoxic Brain Injury
what is brachial plexus injury caused by shoulder dystocia called?
Erb’s palsy
Erb’s palsy
brachial plexus injury caused by shoulder dystocia
Intrapartum management of shoulder dystocia
Tell patient to STOP pushing
Step 1: Call for senior help
Step 2: McRoberts Manoeuvre (Place patient with hips flexed and abducted)
Step 3: Apply Suprapubic Pressure
Step 4: Consider Episiotomy
Step 5: Deliver posterior arm and shoulder and consider internal rotational manoeuvres (e.g. Rubin, Rubin II, Woods’ screw, reverse Woods’ screw)
Step 6: Change position to all fours
Step 7: Consider symphysiotomy, cleidotomy (purposefully breaking one or more clavicles to facilitate delivery) or Zavanelli manoeuvre (reversal of normal movements during delivery with the view of performing an emergency C-section)
Mnemonic for management of shoulder dystocia
Management of shoulder dystocia (HELPER)
call for Help
Episiotomy
Legs up (McRoberts maneuver)
Pressure suprapubically
Enter vagina for shoulder rotation
Reach for posterior shoulder/ Return head into vagina (Zavanelli maneuver)/ Rupture clavicle or pubic symphysis
What is McRoberts manoeuvre?
Place patient with hips flexed and abducted
1st manoeuvre done in shoulder dystocia
McRoberts - done after calling for help
1st thing to do in shoulder dystocia
tell patient to stop pushing
Cleidotomy
purposefully breaking one or more clavicles to facilitate delivery
Zavanelli manoeuvre
reversal of normal movements during delivery with the view of performing an emergency C-section
Symphisiotomy
Symphysiotomy – break pubic symphysis of woman
What does an episiotomy do?
allow better access for internal manoeuvres
What is Breech position?
Abnormal foetal lie in which the buttocks and the lower limbs enter the pelvis first.
Types of breech
Extended Breech: Flexed hips and extended knees
Footling Breech: Foot at the internal cervical os
Flexed Breech: hip and knees flexed
Causes of breech
Idiopathic
Uterine structural abnormalities (e.g. fibroids)
Prematurity
Placenta praevia
Oligohydramnios
Management of breech presentation
if < 36 weeks: many fetuses will turn spontaneously
if still breech at 36 weeks NICE recommend external cephalic version (ECV)- this has a success rate of around 60%. The RCOG recommend ECV should be offered from 36 weeks in nulliparous women and from 37 weeks in multiparous women
if the baby is still breech then delivery options include planned caesarean section or vaginal delivery
How many weeks gestation to do ECV in nulliparous women?
36 weeks
How many weeks gestation to do ECV in multiparous women?
37 weeks
Risks of ECV
Risks: may cause foetal distress that requires emergency C-section, may trigger onset of labour
Contraindications for ECV
Contraindications: placenta praevia, multiple pregnancy, antepartum haemorrhage in preceding 7 days, ruptured membranes, abnormal CTG
When is Elective CS offered in breech?
Generally recommended if ECV is unsuccessful
What maneouvres can be done if opt for a vaginal breech delivery?
Pinard Manoeuvre: poke the baby in the popliteal fossa to make their knees bend
Loveset Manoeuvre: rotate the baby into the transverse position and pull the anterior arm down
Mauriceau-Smellie-Veit Manoeuvre: performed if the baby’s head gets stuck. Rest the baby on your forearm and pull the head downwards. Forceps may be needed if this is unsuccessful.
Pinard manoeuvre (vaginal breech delivery)
Pinard Manoeuvre: poke the baby in the popliteal fossa to make their knees bend
Loveset manouevre (vaginal breech delivery)
Loveset Manoeuvre: rotate the baby into the transverse position and pull the anterior arm down
Mauriceau-Smellie-Veit manoeuvre (vaginal breech delivery)
Mauriceau-Smellie-Veit Manoeuvre: performed if the baby’s head gets stuck. Rest the baby on your forearm and pull the head downwards. Forceps may be needed if this is unsuccessful.
What is cord prolapse?
Obstetric emergency in which the umbilical cord descends below the presenting part of the foetus and through the cervix after rupture of membranes. It leads to constriction of the foetal blood supply and, hence, foetal demise if left untreated.
NOTE: Membranes have to be ruptured
What needs to have happened for diagnosis of umbilical cord prolapse?
Rupture of membranes
RFs for cord prolapse
Abnormal lie
Prematurity
Low birth weight
Polyhydramnios
What should be considered as a diagnosis if CTG abnormalities arise after ROM?
Cord prolapse
What may be seen on CTG in cord prolapse?
Features of foetal distress
Management of cord prolapse
Perform immediate digital examination if cord prolapse is suspected
Immediate senior involvement
Prepare operating theatre for emergency delivery
Elevate presenting part or fill bladder to prevent further cord compression
Consider using tocolytics
If cord is past the introitus –> keep warm and moist
Minimal handling of the cord is advised to prevent vasospasm
Position patient in one of the following positions:
All fours
Knee to chest
Left lateral position
Urgent CTG to confirm foetal viability
Delivery by emergency C-section
NOTE: if cervix is fully dilated and the head is low, vaginal delivery may be possible
What is done immediately if cord prolapse is suspected?
immediate digital examination
What is done first to prevent further cord compression?
Elevate presenting part or fill bladder to prevent further cord compression
Why is minimal handling of the cord advised in cord prolapse?
Prevent vasospasm
What position should the patient be put in during cord prolapse?
All fours
Knee to chest
Left lateral position
How should delivery be done in cord prolapse?
Delivery by emergency C-section
Can vaginal delivery be done in cord prolapse?
Yes, if cervix is fully dilated and the head is low, vaginal delivery may be possible
What should be done if cord is past the introitus in cord prolapse?
If cord is past the introitus –> keep warm and moist
NOTE: Minimal handling of the cord is advised to prevent vasospasm
Best position for cord prolapse
All Fours
Indications for CS
Placenta praevia
Pre-Eclampsia
Prolonged Labour
Foetal Distress
Malpresentation
Placental Abruption
Maternal Request
Risks and complications of CS
For VBAC, what are women advised after one C section?
After one C-section, women will generally be advised to attempt a trial of spontaneous vaginal delivery in the absence of any other indications for C-section
70-75% of cases will be successful
When should VBAC be avoided?
Vaginal birth should be avoided in patients with previous uterine rupture or a previous classical C-section (longitudinal incision rather than transverse)
Indications for IOL
Post-term pregnancy
Prelabour rupture of membranes
Pre-eclampsia
Diabetes mellitus
Deteriorating maternal illness
Antepartum haemorrhage
Foetal growth restriction
Reduced foetal movements at term
What are post term pregnancies associated with?
pregnancies that are prolonged beyond 42 weeks are associated with an increased risk of stillbirth, foetal compromise, meconium aspiration and mechanical problems during delivery
Absolute contraindications for IOL
Placenta praevia
Severe foetal compromise
Breech
What is used to track progression of labour?
The Bishop Score is used to track progression of labour (scores > 8 are suggestive of a favourable cervix and a shorter induction process whereas lower scores are more likely to fail and require C-section)
What is taken into account on the bishop score?
account position, consistency, effacement and dilation of the cervix, and the foetal station
What score on bishop score is suggestive of a favourable cervix?
scores > 8 are suggestive of a favourable cervix and a shorter induction process whereas lower scores are more likely to fail and require C-section
General order of IOL
Bishop Score +/- Membrane Sweep (if possible)
Based on Cervical Dilation
If no evidence of dilation –> Consider pharmacological methods (e.g. prostaglandin pessary or gel)
If evidence of dilation –> Consider mechanical methods (e.g. insertion of a catheter into the cervical canal and inflation of the balloon which stimulates release of endogenous prostaglandins)
Reassess and consider artificial rupture of membranes or IV syntocinon
Complications of IOL
Failure of induction
Pain
Higher rates of instrumental delivery
Hyponatraemia (associated with syntocinon use)
Uterine hyperstimulation
Condition in which prolonged and frequent uterine contractions can lead to foetal hypoxia
If contractions are more frequent than 5 every 10 mins, tocolytic drugs can be used (e.g. terbutaline)
What is prematurity?
Birth before 37 weeks’ gestation. Can be further divided as late preterm (32-37 weeks), very preterm (28-32 weeks) and extreme preterm (less than 28 weeks).
Late preterm
32-37 weeks
Very preterm
28-32 weeks
Extreme preterm
less than 28 weeks
RFs of prematurity
Infection
Cervical Incompetence (e.g. history of LLETZ or cervical surgery)
Stress
Multiple Pregnancy
Smoking
IVF
When should prevention of preterm labour be offered?
To women with a history of spontaneous preterm or mid-trimester loss (16-34 weeks’ gestation) and to women who hae a cervical length of <25mm on USS between 16-24 weeks
What to offer women whom transvaginal ultrasound has been carried out between 16-24 weeks gestation and reveals a cervical length < 25 mm?
Prevention of preterm labour
What to offer women with a history off spontaneous preterm or mid trimester loss?
Prevention of Preterm Labour
What are the options to prevent preterm labour?
prophylactic vaginal progesterone OR prophylactic cervical cerclage
Who should you offer prophylactic vaginal progesterone to? (prevention of preterm labour)
Women with:
NO history of spontaneous preterm birth or mid-trimester loss in whom transvaginal ultrasound scan has been carried out at 16-24 weeks and shows a cervical length < 25 mm
Progesterone is also offered to women with recurrent miscarriage (defined as 3 or more miscarriages)
Who to offer prophylactic cervical cerclage to? (prevention of preterm labour)
Women whom:
A transvaginal ultrasound scan (16-24 weeks) shows cervical length < 25 mm and have either:
Previous pregnancy complicated by PPROM
History of cervical trauma
What is PPROM?
Pre-term premature rupture of membranes
Rupture of membranes occurring prior to the onset of labour <37 weeks
What is PROM?
Premature rupture of membranes
Rupture of membranes occurring prior to the onset of labour >37 weeks
What is PPROM associated with?
an increased risk of infection (chorioamnionitis) and preterm delivery
1st line investigation in PPROM
Offer sterile speculum examination to check for pooling of amniotic fluid
Investigations in PPROM
Primarily a clinical diagnosis
Offer sterile speculum examination to check for pooling of amniotic fluid
If pooling is seen –> Diagnose PPROM
If pooling is NOT seen –> Consider performing an insulin-like growth factor binding protein-1 test or alpha-microglobulin-1 test of the vaginal fluid
If positive –> interpret results based on the clinical findings and consider offering treatment consistent with PPROM
If negative –> do NOT offer antibiotic prophylaxis and explain that this is very unlikely to be PPROM
IMPORTANT: Do NOT perform diagnostic tests for PPROM if labour becomes established in a woman reporting symptoms suggestive of PPROM
What investigation should NOT be done in PPROM?
BIMANUAL –> increases chance of infection
What can be diagnosed if pooling is seen on sterile speculum examination?
PPROMp
pooling of amniotic fluid
PPROM
Example of tocolytic
Nifedipine, atosiban
What investigation to do if pooling is not seen on PPROM?
Consider performing an insulin-like growth factor binding protein-1 test or alpha-microglobulin-1 test of the vaginal fluid
Insulin-like growth factoring binding priotein-1 test
test for PPROM if pooling not seen on Speculum
alpha-micoglobulin-1 test
test for PPROM if pooling not seen on Speculum
Tests for PPROM if pooling not seen on speculum
insulin-like growth factor binding protein-1 test or alpha-microglobulin-1 test
If test for insulin-like growth factor binding protein-1 test or alpha-microglobulin-1 test positive, what next? (PPROM)
interpret results based on the clinical findings and consider offering treatment consistent with PPROM
NOTE: Done if pooling not seen on speculum
If test for insulin-like growth factor binding protein-1 test or alpha-microglobulin-1 test negative, what next? (PPROM)
do NOT offer antibiotic prophylaxis and explain that this is very unlikely to be PPROM
NOTE: NOTE: Done if pooling not seen on speculum
Management of PPROM
Offer oral erythromycin 250 mg QDS for a maximum of 10 days until the woman is in established labour
Alternative: Oral Penicillin
Offer antenatal steroids if less than 36 weeks’ gestation
What abx offered in PPROM
oral erythromycin 250 mg QDS
How long abx offered for in PPROM?
maximum of 10 days until the woman is in established labour
NOTE: oral erythromycin 250 mg QDS
When are antenatal steroids offered in PPROM?
if less than 36 weeks’ gestation
What to do in preterm labour with intact membranes in <29+6 weeks pregnant?
If clinical assessment suggests that the woman is in preterm labour and she is < 29+6 weeks’ pregnant, advise that treatment is indicated
Management for preterm labour with intact membranes and >30 weeks gestation
Consider transvaginal ultrasound scan to measure cervical length (and, hence, determine likelihood of delivery within 48 hours)
If cervical length > 15 mm –> unlikely to be in preterm labour
If cervical length < 15 mm –> make diagnosis of preterm labour
Consider foetal fibronectin as alternative if transvaginal ultrasound is unavailable or unacceptable
If negative –> unlikely to be in preterm labour
If positive –> make diagnosis of preterm labour
What can be done to determine the likelihood of delivery in preterm labour with intact membranes? How?
Consider transvaginal ultrasound scan to measure cervical length (and, hence, determine likelihood of delivery within 48 hours)
Cervical length >15mm on TVUSS in preterm labour with intact membranes
unlikely to be in preterm labour
Cervical length <15mm on TVUSS in preterm labour with intact membranes
make diagnosis of preterm labour
What can be considered instead of TVUSS to determine likelihood of delivery in preterm labour with intact membranes?
Consider foetal fibronectin as alternative if transvaginal ultrasound is unavailable or unacceptable
If negative –> unlikely to be in preterm labour
If positive –> make diagnosis of preterm labour
Negative foetal fibronectin
Unlikely to be in preterm labour
Positive foetal fibronectin
make diagnosis of preterm labour
When to offer tocolysis in preterm labour with intact membranes?
Consider nifedipine if between 24 to 25+6 weeks and have suspected or diagnosed preterm labour with intact membranes
Offer nifedipine if between 26 and 33+6 weeks and have suspected or diagnosed preterm labour with intact membranes
Most common tocolytic
Nifedipine (hence not used close to term in pre-eclampsia)
Alternative to nifedipine as a tocolytic
Atosiban
What can be offered as neuroprotection to those in established preterm labour?
IV Magnesium Sulphate
What can be offered as neuroprotection for those having planned preterm birth within 24 hours?
Administer 4 g IV bolus over 15 mins followed by IV infusion of 1 g/hour until birth or for 24 hours
Monitor for magnesium toxicity (deep tendon reflexes, pulse, blood pressure and respiratory rate)
What must be monitored when giving IV mag sulph?
Monitor for magnesium toxicity (deep tendon reflexes, pulse, blood pressure and respiratory rate)
Antidote for Mag Sulph overdose
IV calcium gluconate 10% 10mls 10 mins
What is the mode of delivery in prematurity?
Offer 24 hours expectant management to see whether labour commences spontaneously
Consider IOL if labour does not commence after 24 hours of expectant management
Consider C-section if in breech position and preterm
Aim for delivery by 34 weeks (earlier if there are signs of infection)
When should you aim for delivery in prematurity?
Aim for delivery by 34 weeks (earlier if there are signs of infection)
