Week 5 Flashcards
Define labour
Labour is a physiological process during which the fetus, membranes, umbilical cord and placenta are expelled from the uterus.
Ferguson’s reflex
neuroendocrine reflex in which the fetal distension of the cervix stimulates a series of neuroendocrine responses, leading to oxytocin production
Hormonal factors influencing onset of labour
Progesterone: This keeps the uterus settled, prevents gap junctions, prevents contractility
Estrogen: makes uterus contract, promotes prostaglandin
Oxytocin: initiates and sustains contractions
How does cervix ripen?
Decrease in collagen fibre alignment
Decrease in collagen fibre strength
Decrease in tensile strength of the cervical matrix
Increase in cervical decorin
5 elements of Bishop’s score
Position
Consistency
Effacement
Dilatation
Level of presenting part/station in Pelvis
Determines when it’s safe to induce labour
Stages of labour
First Stage
Latent phase up to 3-4cms dilatation
Active stage 4cms -10cms (full dilatation)
Second Stage
Full dilatation –delivery of baby
Third Stage
Delivery of baby
Describe latent phase
mild irregular uterine contractions, cervix shortens and softens, duration variable,
May last an uncomfortable few days
Describe active phase
4cms onwards to full dilatation,
Slow decent of the presenting part
Contractions progressively become more rhythmic and stronger
Normal progress is assessed at 1-2 cms per hour
Analgesia
Describe second stage of labour
Starts with complete dilatation of the cervix fully dilated =(10cms) –to delivery of the baby
Nulliparous - prolonged if >3h with reg analgesia, 2h without
Multiparous - prolonged if >2h with rgional analgesia, 1h without
Vaginal exam every 4 hours to decr risk of infection
Describe third stage of labour
Delivery of the baby to expulsion of the placenta and fetal membranes
Average duration 10 minutes but can be 3 minutes or longer
Management 3rd stage of labour
Expectant management- spontaneous delivery of the placenta
Active management: use of oxytocic drugs and controlled cord traction is preferred for lowering risk of post partum haemorrhage
Surgical - 1h prep for surgical removal of placenta under reg analgesia or GA
Describe Braxton Hicks contractions
Braxton-Hicks contractions are sometimes called “false labour” because they give the woman a false sensation that she is having real contractions.
Tightening of the uterine muscles, thought to aid the body prepare for birth
How do you know if it’s true labour?
True labour is when the timing of contractions become evenly spaced, and the time between them gets shorter and shorter (three minutes apart, then two minutes, then one).
Length of time contraction lasts also increases
3 factors influencing labour
POWER: Uterine Contraction
PASSAGE: Maternal Pelvis
PASSENGER: Fetus
Pacemaker of uterus
region of tubal ostia, wave spreads in a downward direction
Synchronisation of contractions waves from both ostia
4 types of pelvis
Gynaecoid pelvis (best for birth)
Anthropoid pelvis
Android pelvis
Platypelloid
Normal foetal position
Longitudinal Lie
Cephalic Presentation
Presents with vertex
Best if occipito-anterior presention
Flexed head
Abnormal foetal position
Presentation; breech, oblique, Transverse lie
Position; frequently “occipito –posterior”
When can sagittal suture be felt?
5-6cm dilated
Analgesia for birth
Paracetamol/ Co-codamol
TENS
Entonox
Diamorphine
Epidural
Remifentanyl
Combined spinal/epidural
Which shoulder delivered first?
Anterior
7 cardinal movements of the foetus at birth
1…Engagement
2…Decent
3…Flexion
4…Internal Rotation
5…Crowning and extension
6…Restitution and external rotation (head goes into optimum pos for shoulder)
7…Expulsion (ant shoulder first)
3 classic signs to indicate separation of placenta from uterus
Uterus contracts, hardens and rises
Umbilical cord lengthens permanently
Frequently a gush of blood variable in amount
Placenta and membranes appear at introitus
Acitve management of 3rd stage labour
Prophylactic administration of Syntometerine
OR
Oxytocin 10 units
Cord clamping/cuttting, controlled cord traction, bladder emptying
Where does placenta separate from?
Plane of separation: Spongy layer of decidua basali
Augmentation vs induction of labour
Augmentation is induction after waters have broken
Methods to induce labour
Artificial rupture of membranes;
- quickest method
- cervix has to be dilated >1cm
Propess (vaginal prostaglandin);
- inpatient only
- risks of uterine hyperstimulation
Cooks balloon (mechanical cervical dilatation);
- outpatient
- only cervical priming method suitable for previous caesarean section
Signs of obstructed labour
Slow/no cervical dilatation
No descent or high presenting part
Caput/moulding of presenting part
Haematuria
“Too good” CTG
Ascites at CS
Bandl’s ring
Describe chorioamnionitis
Intrauterine infection that can be life threatening to baby and to mother
Risks of chorio increase with duration of time between SRM and delivery, particularly if pre-term
Management chorioamionitis
“Golden Hour” of prompt recognition and starting IV antibiotics
Delivery needs to be expedited
PPROM vs PROM
PPROM (Pre-term, pre-labour rupture of membranes)
Antibiotic prophylaxis with erythromycin
Steroids depending on gestation
PROM (Prolonged rupture of membranes)
At term expectant management for first 24 hours after SRM
Offer induction
Signs of maternal sepsis due to chorioamnionitis
Increase MHR, RR, Temp, White Cell Count, CRP, Lactate
Fetal tachycardia/abnormal CTG
Offensive/blood stained liquor
Abdominal pain
Intrauterine pus at section
When would you not do vaginal exam in APH?
Placenta Praevia
Signs of uterine rupture
May have high PP or not in pelvis
Significant abdominal pain despite epidural
Shoulder tip pain
Acute abdomen
Fetal distress
4 Ts for management of PPH
Tone – Use uterotonics to improve
Trauma – Repair tear/uterus
Tissue – Make sure uterus is empty with no placental tissue/membranes
Thrombin – Consider blood products, tranexamic acid
Describe cord prolapse
Descent/prolapse of umbilical cord following rupture of membranes
More common in ARM
Life threatening to baby due to vasospasm of cord
Manage with rapid emergency section
Risk factors for cord prolapse
transverse/unstable lie, polyhydramnios, induced labour with high PP
Describe shoulder dystocia
Bony obstruction of fetal shoulder against maternal pelvis causing delayed delivery and hypoxia
Can cause injuries incl:
- erb’s palsy
- fetal fracture
- PPH
- vaginal tears
- IE
- fetal demise
Risk factors for shoulder dystocia
Previous shoulder dystocia
Diabetes (T1>T2>GDM) even without macrosomia
Fetal macrosomia (i.e. EFW >97th centile, LBW >4.5kg)
Narrow pelvic outlet
Management of shoulder dystocia
80% cases resolved by McRoberts position alone
10% further by suprapubic pressure
Internal manoeuvres then utilised aiming to reduce diameter of shoulders i.e. Woodscrew
Can consider all 4s position and reattempt manoeuvres
May need section or very rarely symphysiotomy to manage
Describe amniotic fluid embolism
Rare complication of labour where amniotic fluid enters systemic circulation and causes acute respiratory and circulatory collapse with coagulopathy
Risks include hyperstimulation and intrauterine demise
Causes of amniotic fluid embolism
Haemorrhage (Obstetric and non obstetric)
Pulmonary embolism
MI
AFE
Septic shock
Eclampsia/Epilepsy
Local anaesthetic toxicity/high block
Uterine inversion
Management maternal collapse
2222 citing maternal collapse and location
ABCDE multidisciplinary approach, remember left lateral and uterine displacement to improve resuscitation
Stabilise and deliver followed by postpartum management and ITU care
Describe uterine inversion
Literally uterus turning inside out after delivery of baby
Usually due to trying to pull a placenta that has not separated
Causes neurogenic shock followed by PPH
- low BP, no tachcardia, often strong bradycardia
Management of uterine inversion
Prompt recognition and replacement of uterus with manual pressure or using high volume warmed saline via a suction cup into vagina.
Placenta then left in situ
Delivery of placenta or ongoing management of inversion then done in theatre
Risk factors for OASI
Risk factors include primiparity, operative birth, macrosomia, hands off approach, previous OASI and quick delivery
Define maternal collapse
acute event involving cardio resp system or CNS causing reduced/absent conscious level at any stage in pregnancy and up to 6 weeks after birth
can result in cardiac arrest if not treated properly
What are the physiological and anatomical changes in pregnancy that affect resuscitation?
Aortocaval compression
- significantly reduces cardiac output from 20 weeks
Respiratory changes
- lung function, diaphragmatic splinting and increased oxygen consumption makes pregnant women become hypoxic more readily
Intubation
- more difficult esp with laryngeal oedema and bigger boobs
Aspiration
- more likely due to progestrogenic effect on oeso sphincter
Circulation
Causes of maternal collapse
Drugs
PE
AFE
Haemorrhage
Anaphylaxis
Aortic dissection
Cardiac cause
Hyoglycaemia
Sepsis
4H and 4T and 1E causes of maternal collapse
Hypovolaemia
Hypoxia
Hypo/hyperkalaemia/hyponatraemia
Hypothermia
Thromboembolism
Toxicity
Tension pneumothorax
Tamponade
Eclampsia/pre-eclampsia
How to relieve aortocaval compression?
Left lateral tilt from head to toe during maternal CPR
- 15-30deg
When should you consider perimortem CPR?
Initiate after 4 mins CPR
Achieve delivery after 5 mins CPR
- rationale is due to the fact pregnant women get hypoxic much more quickly
- irreversible brain damage to mother can occur within 4-6 mins
Should be done where collapse and resus take place - not time for moving the pt
PPH definition
SVD >500ml
Operative vaginal delivery >750ml
C-section >1000ml
4 T causes of PPH
tone (uterine atony)
trauma (perineal tears, cervical tears)
tissue (placenta, fragment of placenta)
thrombin (coag problems)
Uterotonics used in PPH
Syntocinon
Ergometrine
Carboprost
How much tranexamic acid for 10% blood loss?
1g
Management PPH without drugs
IU balloon
- presses on BVs from inside out, stays in for 24h
Brace sutures
- sutures the whole way around uterus and pull down, only via laparotomy/C-section
IR
- blocking of uterine arteries
Hysterectomy
- as last resort
Active management of 3rd stage
Up to 30 mins
Uterotonics
Cord clamping
Controlled cord clamping
Define morbidly adherent placenta
Placenta abnormally adherent to womb, e.g. within increta, accreta, percreta, outwith uterus
Main risk factor: multiple C-sections
Features of uterine inversion
Uterus flips inside out
Can be due to cord avulsion etc
Massive vagal response from mum due to excessive bleeding
Put hand it to flip back up
HELPERR management of shoulder dystocia
Call for Help
Evaluate for Episiotomy
Legs (McRobert’s)
External Pressure (suprapubic)
Enter (rotational manoeuvres)
Remove posterior arm
Roll patient onto hands and knees
Risk factors for post-partum sepsis
Anaemia
Prolonged rupture of membranes
Long labour
Assisted delivery
Raised BMI
Diabetes
Sources of PP sepsis
Uterine e.g. endometritis
Skin/wound esp episiotomy
Urine
Breast e.g. mastitis
Chest
Other
Why are pregnant women at higher risk of sepsis?
Relative immunosuppresion in pregnancy, maternal population at increased risk of sepsis
Shift from cell mediated to humoral immunity
Risk factors for maternal sepsis
Pre-natal invasive diagnostic procedures (i.e. amniocentesis, CVS)
Cervical suture
Prolonged rupture of membranes
Operative delivery
RPOC
Diabetes
Obesity
Anaemia
Immunosuppression
Signs/symptoms of maternal infection
Offensive PV loss
Sore throat
Rash
Abdominal pain
Urinary frequency, dysuria
Productive cough
Wound erythema, purulent discharge
Breast erythema, tenderness
(dependent on origin of infection e.g. mastitis, endometritis)
Signs of systemic inflammatory response synrome (SIRS)
Temp >/38Cor <36C
HR >100bpm
Resp rate >20/min
White cells >16x109/L or <6x109/L
Altered mental state (confusion/hyperactivity)
Unexplained coag (prolonged PTR etc)
Blood to order in sepsis
FBC, U+E, LFTs, Coag, Glucose, Lactate, CRP
Paired cultures
Antibiotic management of suspetced maternal sepsis
IV co-amoxiclave within 1h
+/- gentamicin depending on severity
Clindamycin if sore throat (GAS)
If penicillin allergic: Clinda + gent
If septic shock: Tazocin, clindamycin + gentamicin
Antenatal/intrapartum sources of infection
Chorioamnionitis
Genitourinary
- Including HSV
Respiratory
- Influenza
- COVID
- CAP
Post-natal sources of infection
Endometritis +/- RPOC
LUSCS wound/episiotomy
Mastitis
Urinary tract (especially if catheterised)
CNS (if regional anaesthetic, suspect meningitis e.g. in spinal block)
Define chorioamnionitis
Inflammation of the amniochorionic (fetal) membranes of the placenta, typically in response to microbial invasion
Org: E.coli, mycoplasma, anaerobes, group B strep
Risk of neonatal sepsis
Presentation of chorioamnionitis
offensive PV loss, fetal CTG concerns, maternal pyrexia and abdominal pain
Management chorioanionitis
Broad spectrum IV antibiotics
Delivery
If not in established labour needs IOL or LUSCS
Manage risk of PPH with active 3rd stage syntocinon infusion
Avoid PP IU contraception
Stratifying risk of Group B strep
Most babies to GBS colonised mothers will be fine
Higher risk in pre-term labour or PRM
Rarely cause neonatal pneumonia/meningitis and sepsis
5% mortality risk in GBS infection, 7% long-term disability
When to offer intrapartum antibiotics in GBS?
Prophylaxis (benzylpenicillin/clindamycin)
If GBS detected antenatally
Prev baby affected by GBS
Delivery <37 weeks
Risk factors for endometritis
Operative delivery
Prolonged labour,
Retained products of conception
Presentation of endometritis
abdominal pain, abnormal PV bleeding, offensive PV loss following delivery/miscarriage/termination
Management of endometritis
Treatment with co-amoxiclav +/- surgical evacuation of uterus if significant RPOC
Co-trimoxazole +metronidazole if penicillin allergic
Pres of mastitis
Usually unilateral painful and inflamed breast in breastfeeding mothers
Management of mastitis
First line - complete breastemptying via feeding/expressing, warm compress and NSAIDs
Antibiotics - fluclox if no improvement/signs of sepsis
No response to antibiotic , suspicion of fluctuant swelling - ref to breast team for USS and drainage
Features of epidural abscess
Rare cause of sepsis in those having had regional anaesthesia
Presents with back pain, fever, potential neuro deficit
High mortality/morbidity if undiagnosed
Management of epidural abscess
Consider imaging with MRI to diagnose
Treatment with IV antibiotics +/- surgical decompression if no response or neurological concerns
- vanc, metro, cefotaxime
- open vs CT guided surgery to drain
Define APH/bleeding in late pregnancy
> / 24 weeks and before end of second stage of labour (essentially before baby delivered)
Most commonly placental abruption and placenta praevia
Ensure it’s actually coming form vagina!!!!!
Causes of APH
Placental Problem- Placenta Praevia
Placental Abruption
Uterine problem- rupture
Vasa Praevia
Local causes- ectropion, polyp, infection. carcinoma
Indeterminate
Quantification of APH
Spotting (staining, wiping)
Minor (<50ml, settled)
Major (50-1000ml, no shock)
Massive (>1000ml, maybe shock)
Describe placental abruption
separation of a normally implanted placenta
vasospasm, arteriole rupture, blood escapes into amniotic sac or into myometium
tonic contraction, interrupts placental circ = hypoxia
results in couvelaire uterus (blood goes into peritoneal cavity)
RFs of placental abruption
PET
Unknown
Trauma
Smoking, drugs
Thrombophilia, renal disease, diabetes, hypothyroid
Polyhydramnios
Multiples
Preterm
Plac insufficiency
prev abruption
Presentation of placental abruption
Severe continuous abdo pain, differentiated from intermittent contractions
Bleeding
Preterm labour
Maternal collapse (maybe if mother shocked, hypotensive from blood loss etc)
Generally disteressed pt, signs not always consistent with revelaed blood
Abdo exam signs in plaental abruption
Uterus LFD or normal
Uterine tenderness
Woody hard uterus
Fetal parts difficult to identify
May be in preterm labour
Fetal signs of placental abruption
Bradycardic, absent heart rate (IU death0
CTG shows irritabile uterus (low conractions, FH abnormality)
Complications placental abruption
Hypovolaemic shock
Anaemia
PPH (25% )
Renal failure from renal tubular necrosis
Coagulopathy/DIC (FFP, cryoprecipitate)
Infection
Complications of blood transfusion
Thromboembolism
Prolonged hospital stay
Psychological sequelae
Mortality - rare
Prevention of placental abruption in APS
LMWH and low dose aspirin
Define placenta praevia
- placenta lies directly over the internal os
- after 16 weeks, low lying + less than 20 mm from internal os on TA or TV scanning
Risk factors for placenta praevia
- previous placenta praevia
- incr number of prior C-sections
- prev termination
- multiples, multiparity, assisted conception
- smoking
- deficient/abnormal uterus
How is placenta praevia identified?
- placental location at fetal anomaly 20 week scan
- if persistent PP or lowlying = scan at 32 and 36 weeks
- via TV scan
Presentation of placenta praevia
- Painless bleeding >24 weeks;
- Usually unprovoked but coitus can trigger bleeding
- Bleeding can be minor eg spotting/ severe
- Fetal movements usually present
- Proportional systemic effects to volume of blood loss etc
Exam findings in placenta praevia
- Soft non tender uterus
- High presenting part
- Malpresentation
- CTG normal
- Obs depends on blood loss/level of distress/etc
What exam should you never perform in placenta praevia?
- vaginal exam!!!!!
- speculum may be done by specialist
When is MRI used in placenta praevia?
to exclude placenta accreta
Deciding on method of delivery in placenta praevia
to exclude placenta accreta
Management of bleeding placenta praevia
Admit and RESUS
2 grey IVs
Bloods etc
Fluids
Anti D
Xmatch 4-6 units RBC
May need Major Haemorrhage protocol
Differences with C section in placenta praevia
- consent includes hysterectomy and risk of GA
- cell salvage
- vertical incisions of skin an uterus before 28 weeks
- avoid cutting placenta
Define placenta accreta
- A morbidly adherent placenta: abnormally adherent to the uterine wall
- Multiple C sections
Management of placenta accreta at delivery
Prophylactic internal iliac artery balloon
Caesarean hysterectomy
Blood loss >3L expected
Conservative Management – incision upper segment
Defien uterine rupture
Full thickness opening of uterus
Including serosa
If serosa is intact
- dehiscence
Risk factors for uterine rupture
previous caesarean section/ uterine surgery eg myomectomy
Multiparity and use of prostaglandins/ syntocinon increase risk
Obstructed labour
Symptoms of uterine rupture
Severe abdominal pain
Shoulder-tip pain
Maternal collapse
PV bleeding
SIgns of uterine rupture
Intra-partum - loss of contractions
Acute abdomen
Presenting part rises
Peritonism
Fetal distress / IUD
Define vasa praevia
Unprotected fetal vessels traverse the membranes below the presenting part over the internal cervical os
Rupture during labour or at amniotomy
Fetal mortality ~60%
Diagnosis of vasa praevia
Ultrasound TA & TV with doppler
Clinical
- ARM and sudden dark red bleeding and fetal bradycardia / death
Types of vasa praevia
Type I
- when the vessel is connected to a velamentous umbilical cord
Type II
- when it connects the placenta with a succenturiate or accessory lobe.
Risk factors for vasa praevia
PLacental anomalies - bilobed, vessel abnorms
Low lying placental history
Multiple pregnancy
IVF
Management of vasa praevia
Antenatal diag
Steroids from 32w
Inpatient management if preterm risk 32-34w
Elective C section before labour 34-36w
APH from vasa praevia - emergency C section
Placenta histology
Causes of vasa praevia
Cervical causes
ectropion
Polyp
carcinoma
Vaginal causes
Unexplained (1/3)
Key prevention of PPH
ID intrapartum risks
Active management of 3rd stage
- Syntocinon/syntometrine IM/IV
How to stop the bleeding in PPH?
TRABEXAMIC ACID
Uterine massage- bimanual compression
Expel clots
5 units IV Syntocinon stat
40 units Syntocinon in 500ml Hartmanns - 125 ml/h
Foleys Catheter- hrly volumes
500 micrograms Ergometrine
Carboprost, misoprostol
Theatre if req
Bleeding repairs in PPH
Non - Surgical
Packs & Balloons – Rusch Balloon, Bakri Balloon
Tissue Sealants
Interventional Radiology : Arterial Embolisation
Surgical
Undersuturing
Brace Sutures – B-Lynch Suture
Uterine Artery Ligation
Internal Iliac Artery Ligation
Hysterectomy
