Delivery Flashcards
Define IOL
Artificial Induction of labour
Indications for induction of labour
Prolonged gestation - 40+0 to 40+14 weeks gestation Premature rupture of membranes - > 37 weeks Maternal health problems - hypertension, pre-eclampsia, diabetes and obstetric complications Intrauterine foetal death - mother physically well and membranes intact
Contraindications for IOL
Absolute - cephalopelvic disproportionation - major placenta praevia - vasa praevia - cord prolapse - transverse lie - active primary genital herpes - previos classical caesarean section Relative - breech presentation - triplet or higher - two or more low transverse caesarean sections
Methods of induction of labour
Vaginal prostaglandins
- ripen cervix and contraction of smooth muscle
- either tablet, gel or pessary
- max one cycle in 24 hours
Amniotomy
- membranes artificially ruptured using amnihook
- releases prostaglandins
- only performed in cervix ripe
Membrane sweep
- offered at 40 and 41 weeks gestation to nulliparous women and 41 weeks for multiparous
- adjunct of IOL
- increases likelihood of spontaneous delivery reducing need for formal induction
- separate chorionic membrane from decidua -> releases prostaglandins
What is the Bishop score
Assessment of cervical ripeness
- > 7 = cervix ripe/favourable - high chance of success of IOL
- < 4 = labour unlikely to progress naturally and prostaglandin required
Features of the Bishop score
Cervical dilation (cm) < 1 = 0 1-2 = 1 2-4 = 2 > = 4 Cervical length (cm) > 4 = 0 2-4 = 1 1-2 = 2 <1 = 3 Station - relative to ischial spine -3 = 0 -2 = 1 -1/0 = 2 \+1/+2 = 3 Consistency firm = 0 average = 1 soft = 2 Position posterior = 0 mid/anterior = 1
CTG monitoring during labour
Prior to IOL reassuring foetal heart rate must be confirmed by cardiotocography
Intermittent auscultation
If oxytocin infusion started monitor using continuous CTG
Complications of induction of labour
Failure of indcution (15%) - offer further cycle of prostaglandins or caesarean section Uterine hyperstimulation - contractions last too long or are too frequent -> foetal distress - managed with tocolytic agents such as terbutaline Cord prolapse - can occur at time of amniotomy Infection - risk is reduced by using pessary vs tablet/gel as fewer vaginal examinations required to check progress Pain - IOL more painful than spontaneous - epidural often required Increased rate of further intervention - 22% require emergency sections - 15% require instrumental deliveries Uterine rupture
Define caesarean section
Delivery of a baby through surgical incision in abdomen and uterus
Either elective or emergency
Classification of emergency caesarean
Category 1 - must be born within 30 minutes
- immediate threat to life of women or foetus
Category 2 - within 75 mins
- maternal or foetal compromise that is not immediately life-threatening
Category 3 - scheduled
- no maternal or foetal compromise
- booked elective LSCS but admitted earlier
Category 4 - elective
- time to suit women/staff
Indications for planned C-section
Breech presentation at term
Other malpresentations
Twin pregnancy
Maternal medical conditions - cardiomyopathy
Foetal compromise - early onset growth restriction
Transmissible disease - poorly controlled HIV
Primary genital herpes
Placenta praevia
Maternal diabetes - foetal weight over 4.5kg
Previous 3rd/4th degree perineal tear - where patient symptomatic
Maternal request
Indications for emergency C-section
Failure of labour to progress
Suspected/confirmed foetal compromise
When are elective c-sections planned
After 39 weeks
- reduce respiratory distress in the neonate
- if needed before administer corticosteriods to stimulate development of surfactant in foetal lungs
Pre-operative procedure for C-section
FBC and G+S - average blood loss 500-1000ml H2-receptor antagonist - Ranitidine - risk of aspiration of gastric contents into lung - due to pressure applied by gravid uterus on stomach Risk score for VTE - anti-thromboembolic stockings +/- LMWH
Anaesthesia procedure for C-section
Usually regional - topped up epidural or spinal Sometimes GA required - contraindication to regional - failure of regional - concerns about foetal wellbeing and need to expedite delivery
Spinal vs epidural anaesthesia
Spinal - directly into subarachnoid space - 1 time using needle - shorter length Epidural - epidural space - catheter so continuous - longer length
Operative procedure for C-section
Woman positioned with left lateral tilt of 15 degrees - reduce risk of supine hypotension
Indwelling Foley’s catheter catheter inserted - drains bladder and reduce risk of bladder injury
Anaesthesia
Skin prepared with antiseptic solution and antibiotics
Skin incisions - Pfannenstiel
Sharp/blunt dissection through abdomen
- skin
- Camper’s fascia - superficial fatty layer of subcut tissues
- Scarpa’s fascia - deep membranous layer of subcut tissue
- Rectus sheath
- Rectus muscle
- Abdominal peritoneum
- Visceral peritoneum
- Uterine incision
- Baby delivered with fundal pressure from assistant
- Placenta delivered
Oxytocin 5iu given IV to aid delivery of placenta
Everything closed
Post-op management of C-section
Ob and lochia monitored
Early mobilisation, eating and drinking and removal of catheter
Aim to discharge 1 day later
Complications of C-section
Immediate
- postpartum haemorrhage
- wound haematoma
- intra-abdominal haemorrhage
- bladder/bowel trauma
- neonatal
- transient tachypnoea of the newborn
- foetal lacerations
Intermediate
- infection
- UTI
- endometritis
- resp
- VTE
Late
- urinary tract trauma (fistula)
- subfertility
- regret and other negative psychological sequelae
- rupture/dehiscence of scar at next labour (VBAC)
- placenta praevia/accrete
- caesarean scar ectopic pregnancyDefine operative vaginal delivery
Use of an instrument to aid delivery of foetus
- Ventouse or forceps - choice is operator dependent
- if after 3 contractions and pulls no reasonable progress attempt abandoned
Features of ventouse
Attaches to foetal head by vacuum
- electrical pump attached to a silastic cup - only suitable if foetus in occipital-anterior position
- hand-held disposable Kiwi - used for all positions
Cup applied to centre over flexion point on the foetal skull - traction applied during contractions
Associations of ventouse delivery
Lower success rate Less maternal perineal injuries Less pain More cephalhaematoma More subgaleal haematoma More foetal retinal haemorrhage
Features of forceps delivery
Double bladed instruments
- Rhodes, Neville-Barnes or Simpsons - used for OA positions
- Wrigley’s - used in C-section
- Kielland’s - used for rotational deliveries
Blades introduced into pelvis and applied to side of foetal head
- blades locked together
- gentle traction applied during uterine contractions following J shape of maternal pelvis
Associations of forcep delivery
Higher rate of 3rd/4th degree tears
Less often used to rotate
Doesn’t require maternal effort
Indications for operative vaginal delivery
Maternal
- inadequate progress
- nulliparous women - expect delivery in 2 hours
- multiparous women - expect delivery in 1 hour
- maternal exhaustion
- maternal medical conditions meaning active pushing or prolonged exertion should be limited
- intracranial pathologies
- maternal congenital heart diseases
- severe hypertension
Foetal
- suspected foetal compromise in second stage of labour - diagnosed by CTG monitoring or foetal blood sample
- clinical concerns
- significant antepartum haemorrhage
Contraindications for operative vaginal delivery
Absolute
- unengaged foetal head in singleton pregnancies
- incompletely dilated cervix in singleton pregnancies
- true cephalo-pelvic disproportion
- breech or face presentation
- preterm gestation for ventouse < 34
- high likelihood of any foetal coagulation disorder for ventouse
Relative
- severe non-reassuring foetal status with station of head above level of pelvic floor
- delivery of second twin when head has not engaged or cervix reformed
- prolapse of umbilical cord with foetal compromise when cervix completely dilated and station is mid cavity
Pre-requisites for instrumental delivery
Fully dilated Ruptured membranes Cephalic presentation Defined foetal position Foetal head at least level of ischial spines and no more than 1/5 palpable per abdomen Empty bladder Adequate pain relief Adequate maternal pelvis
Classification of operative vaginal deliveries
Outlet
- foetal scalp visible with labia parted
- foetal skull reached pelvic floor
- foetal head on perineum
Low
- lowest presenting part is +2 or further below ischial spines
- > 45 degrees - rotation needed
- < 45 degrees - no rotation needed
Midline
- 1/5 palpable abdominally
- lowest part is above +2 but lower than ischial spines
- > 45 degrees - rotation needed
- < 45 degrees - no rotation neededComplications of operative vaginal delivery
Foetal
- neonatal jaundice
- scalp lacerations
- cephalhaematoma
- subgaleal haematoma
- facial bruising
- facial nerve damage
- skull fractures
- retinal haemorrhage
Maternal
- vaginal tears - 3rd/4th degree
- 1:100 in normal delivery
- 4:100 in ventouse
- 10:100 in forceps
- VTE
- incontinence
- PPH
- shoulder dystocia
- infectionDefine PROM
Premature Rupture of Membranes
- rupture of foetal membranes at least 1 hour prior to onset of labour at 37+ weeks gestation
- occurs in 10-15%
- associated with minimal risk to mother and foetus due to advanced gestation
Define P-PROM
Pre-term Premature Rupture of Membranes
- rupture of foetal membranes occurring before 37 weeks
- complicates 2% of pregnancies - 40% of preterm deliveries
- higher rates of foetal and maternal complications
Pathophysiology of PROM/P-PROM
Foetal membranes weaken at term - apoptosis and collagen breakdown by enzymes
Earlier weakening of membranes
- earlier activation of normal physiological process - higher than normal levels of apoptotic markers and MMPs in amniotic fluid
- infection - inflammatory markers contribute to weakening
- gender predisposition
Risk factors for PROM/P-PROM
Smoking Previous PROM/pre-term delivery Vaginal bleeding during pregnancy Lower genital tract infection Invasive procedures - amniocentesis Polyhydramnios Multiple pregnancy Cervical insufficiency
Clinical features of PROM/P-PROM
‘Broken waters’ - painless popping sensation followed by gush of watery fluid leaking from vagina or gradual leaking or change in colour/consistency of vaginal discharge
On speculum examination fluid draining from cervix and pooling in posterior vaginal fornix
Differential diagnosis of PROM/P-PROM
Urinary incontinence Normal vaginal secretions of pregnancy Increased sweat/moisture around perineum Increased cervical discharge - infection Vesicovaginal vaginal fistula Loss of mucus plug
Investigations for PROM/P-PROM
Maternal history
Positive examination findings
USS not routinely used unless unclear
High vaginal swab should be taken - may grow group B Streptococcus
Management of PROM/P-PROM
Most will enter labour in 24-48 hours
If not
- < 34 weeks - aim for increased gestation till 34 weeks
- monitor for clinical chorioamnionitis and avoid sexual intercourse
- prophylactic erythromycin
- corticosteriods
- 34-36 weeks - IOL and delivery recommended
- monitor for clinical chorioamnionitis and avoid sexual intercourse
- prophylactic erythromycin
- corticosteriods
- clindamycin/penicillin during labour if GBS isolated
- > 36 weeks - IOL
- watch and wait for 24 hours or consider IOL and delivery
Complications of PROM/P-PROM
Outcome of PROM generally correlates with gestational age
Greater latency period the lower the gestational age - increases risk of complications
- chorioamnionitis - inflammation of foetal membranes due to infection
- oligohydramnios - esp if less than 24 weeks increases risk of lung hypoplasia
- neonatal death - complications associated with prematurity, sepsis and pulmonary hypoplasia
- placental abruption
- umbilical cord prolapse
Define VBAC
Vaginal birth after caesarean section
- planned vaginal birth after C-section is clinically safe for majority of women who have had one prior LSCS
Risk factors for VBAC
Multiple pregnancy
Macrosomia
Maternal age > 40 years old - risk of uterine rupture
Feature of VBAC
If successful shorter hospital stay and recovery
Risk of uterine rupture - 0.5%
5% risk of anal sphincter injury
Risk of maternal death - 4 in 100,000
If successful good chance of successful future VBACs
2-3% risk of transient resp difficulties for neonate
Risk of hypoxic ischaemic encephalopathy to neonate
Risk of stillbirth beyond 39 weeks whilst awaiting spontaneous labour
Features of elective repeat caesarean section
Longer recovery Almost negates risk of uterine rupture No risk of anal sphincter injury Risk of maternal death - 13 in 100,000 Subsequent pregnancies likely to require C-section 4-5% risk of neonatal resp morbidity < 0.01% risk of neonatal HIE With each C-section delivery there is an increased risk of placental problems (accreta and praevia) and adhesion formation
Define uterine rupture
Full-thickness disruption of the uterine muscle and overlying serosa
- foetus can be extruded from the uterus -> foetal hypoxia and larger internal maternal haemorrhage
Risk factors for uterine rupture
Previous C-section - esp classical incisions Previous uterine surgery - myomectomy Induction of labour Obstruction of labour Multiple pregnancy Multiparity
Management of VBAC delivery
Women should be in hospital setting with facilities for emergency caesarean and advanced neonatal resuscitation
Should be continuous CTG monitoring
Additional analgesic requirements may indicate uterine rupture
Cautious with augmentation - increased risk of uterine scar rupture
After 39 weeks an elective repeat section is recommended delivery method
VBAC contraindications
Absolute - classical caesarean scar - previous uterine rupture - placenta praevia Relative - complex uterine scars - > 2 lower segment C-sections
