Obstetrics Flashcards
List the criteria for normal labor
Regular uterine contractions along with cervical dilation
- begins spontaneously
- proceeds at normal rate
- proceeds without intervention
- results in spontaneous vaginal delivery
Describe the stages of labor
1st Stage (Contraction and cervical dilatation)
- latent phase is prodrome labour and not clinically classified as true labour (6-20h in nulli and 4-13 in multi)
- active phase is true labour and cervical dilation of >3-4cm
- begins with acceleration phase
- phase of maximum slope where have cervical dilation to 10cm
- deceleration phase into 2nd stage
- nulli have 1.2-3.0cm/hr and multi have 1.5-5.7cm/h
2nd Stage
- fetal descent and delivery over 1-3 in nulli and 0.5-1 in multi
3rd Stage
- delivery of placenta
Discuss the changes in stage 1 of labour
- uterus changes where upper uterus have stronger contractions resulting in shrinking and lower uterus have smaller contractions and get bigger
- cervix becomes effaced and then dilated
Discuss the changes in stage 2 labor
Baby 7 Cardinal Movements
- engagement where head engaged to ischial spine
- descent where downward passage through cervix
- flexion where partial flexion of head as baby passess through pelvis
- internal rotation where rotate head from occiput transverse to either anterior or posterior
- extension where extend head once past pubic symphysis
- restitution once head delivered it rotates back to original position
- expulsion where further descent bring shoulder past pubic symphysis
Discuss the 5 cardinal findings on physical exam of pregnant women
Effacement - smoothness of the cervix relative to the uterus Dilatation - dilation of the cervix Station - relation of head to ischial spines Presentation - foremost part of the fetus within or near birth canal - normal is cephalic vertex Position - orientation of the baby occiput relative to maternal pelvis - normal is occiput anterior
What are the four cardinal questions for women in labour
Cardinal - fetal movement (>6 per hour normal) - bleeding per vagina - rupture of membranes - contrations including regularity, length and pain History - gestational age - maternal age - GTPAL - complications during pregnancy - prenatal care
Discuss how to differentiate true and false labour
True - contractions: regular - frequency: decreasing interval - intensity: worsening - location: back and abdomen - cervical change: dilating - effect of sedation: no change False - contractions: irregular - frequency: interval increasing - intensity: not changing - location: lower abdomen - cervical change: no change - effect of sedation: diminish
Discuss the management of Stage 1 Labor
Preparation - epidural - GBS positive require prophylaxis - Rh- require rhogram Management - mark progress by cervical dilation per hour - should take between 5-10 hours - assess for dystocia if cervical dilation <1.2cm/h in nulli or 1.5/h in multi
Discuss the management of Stage 2 labour
- progress by monitoring station
- assess correct position by Leopold and vaginal exam
- no time limit as long as no fetal compromie
Indications for pushing - exceeded 3rd hour of stage 2
- patient without epidural feel urge to push
- nulliparous with epidural when fetus head visible or station >+2 and occiput anterior
- multiparous with epidural when urge to push, head is visible, or station >+2 with occiput anterior
Reassessment - dystocia if <1cm/hr descent in nulliparous or <2cm/hr in multi
- maximum duration if after 2 hours of pushing
Discuss the management of stage 3 of labour
- placenta should deliver within 15 minutes
- if no delivery within 30-45 minutes then active management
- after delivery than clamp and cut cord (delay by >1 minutes if <37 weeks)
Discuss the different terminology of twins Dizygotic Monozygotic Monoamniotic Monochorionic
Dizygotic - fertilization of 2 different eggs with 2 different sperm Monozygotic - fertilization of 1 egg with 1 sperm Monoamniotic - twins sharing same amniotic sac - di is have own amniotic sac Monochorionic - twins sharing same placenta - di is have each their own
Complications
- monoamn and monochori have highest risk of complications
Splitting
- di - di split within 3 days
- diamniotic and mono split within 3-8 days
- mono - mono split within 8-13 days
- conjoined split after 13 days
Discuss the complications of multiple gestations
Maternal - hyper-emesis gravidarum - gestational diabetes or hypertension - anemia Pregnancy - polyhydramnios - placental abruption or previa - cord anomalie - twin transfusion syndrome Delivery - increased morbidity and mortality - premature preterm rupture of membranes - preterm labor - prolonged labor - malpresentation - umbilical cord prolapse - increased risk of C - section - post-partum hemorrhage Fetal - IUGR
Discuss the presentation and management of twin-twin transfusion syndrome
- 10% of mono-chorionic twins
Pathophysiology - arterial blood from twin A passes through placenta and into twin B resulting in twin A having reduced blood supply and IUGR and twin B having excessive blood supply and hypervolemia, congestive heart failure, polycythemia
Investigation - ultrasound with doppler flow
Management - recipient twin get serial amniocentesis to reduce volume
- donor twin get intra-uterine blood transfusion
Discuss the management of multiple gestation
- weekly testing from 24 weeks gestation
- serial ultrasound every 2-3 weeks from 28 weeks to assess growth
- weekly Doppler to assess growth
- 3rd trimester cervix checks for preterm delivery
Discuss the interpretation of fetal heart rate monitoring
Contractions:
- frequency (normal is less than 5 in 10 minutes, tachsystole is >5 per 10 minutes)
- duration (normal is less than 90 seconds)
- resting tone (>30 seconds between contractions)
- timing (regular, singular contractions; tetanic is prolonged contraction lasting >3 minutes, paired or tripling is multiple occurring right next to eachother)
Baseline
- normal is 110-160 per minute
Variability
- fluctuations in baseline rate
- undectable is no variability
- minimal is <5bpm in variability
- moderate is 6-25bpm in variation (normal)
- marked is >25bpm
Acceleration
- abrupt increase in fetal heart rate greater than 15bpm lasting 15 seconds to 2 minutes and reaching peak in <30 seconds
Deceleration
- discussed on another card
Discuss the different types of deceleration
Variable
- abrupt decrease in FHR that is >15bpm below baseline and lasts 15 seconds to 2 minutes and reaches nadir <30 seconds
Complicated
- deceleration to <70bpm lasting >1 minute
- low variability of baseline
- biphasic deceleration
- prolonged secondary acceleration (overshoot by 20bm for >20 seconds)
- slow return to baseline
- presence of fetal tachycardia or bradycardia
Repetitive
- >3 decelerations
Late Deceleration
- gradual decrease in FHR and return to baseline after reaching nadir >30s after contraction
Early Deceleration
- gradual decrease in FHR and return to baseline after reaching nadir >30s before contraction
List the differential for fetal tachycardia
Maternal - Infection - dehydration - hyperthyroidism - anxiety Fetal - infection - prolonged fetal activity - chronic hypoxemia - cardiac anomaly - anemia
Discuss the management of fetal tachycardia
Intra-uterine resuscitation
- reposition mother to left or right lateral decubitus
- supplement O2
- IV bolus
Determine Cause
Intervention
- if persists >80 minutes then fetal scalp pH or delivery to be considered
List the differential for fetal bradycardia
Maternal - hypotension - medication - maternal position - connective tissue disease Fetal - umbilical cord occlusion - fetal hypoxia/acidosis - vagal stimulation - fetal cardiac defect
Discuss the Management of Fetal Bradycardia
Intra-uterine resuscitation
Determine cause
Intervention
- if <100bpm or persistant then fetal scalp pH or delivery
List the Indications and Findings of a fetal scalp blood sample
Indications - atypical or abnormal fetal tracings - digital fetal scalp stimulation does not result in acceleration Interpretation - >7.25 then continue to observe - 7.21-7.24 then repeat in 30 minutes - <7.2 then immediate delivery
List the causes of abnormal variability
Minimal - fetal sleep - prematurity - medications: narcotics, beta-blockers, betamethasone - hypoxic acidemia - congenital abnormality Marked - mild hypoxia - fetal gasping Sinusoidal - severe fetal anemia
List the causes of acceleration
- presence of acceleration is reassuring meaning pH >7.2
- no presence is not concerning however
List the causes of Uncomplicated variable deceleration
- vagal stimulation due to cord compression
- manage with observation and intra-uterine resuscitation
List the causes of complicated, variable deceleration
- fetal acidemia Management - intra-uterine resuscitation - amnioinfusion of RL or NS - confirm fetal well being with scalp monitor - consider deliver
list the causes of late deceleration
Maternal - maternal hypotension - uterine tachysystole Placental - insufficiency Fetal - fetal acidemia Management - repetitive or >50% contractions require fetal scalp or deliver
List the non-pharmacological pain relief in pregnancy
Minimal Training - continuous support - distraction - massage - hydrotherapy - vertical position (best for 1st stage) Specialized Training - biofeedback - intradermal water infection - TENS - acupuncture
Discuss the pain management of intermittent bolus parenteral opioids
Types:
- morphine and fentanyl most common
- fentanyl have reduced effect on fetus
Indication
- 3rd line
- used for early labor or very late stage where epidural not an option
Advantage
- simple and easy to use with quick onset
Disadvantage
- maternal side effects of respiratory depression, drowsiness and delayed gastric emptying
- fetal side effects of decreased FHR variability and respiratory depression
Discuss the pain management of PCA
- fentanyl used in PCA Indication - 2nd line - intrauterine fetal demise or termination Advantages - provides instantaneous relief at lower doses - have reduced maternal side effects Disadvantage - specialized equipment - small doses not as effective
Discuss pain management of inhalation nitrous oxide
- entonox (50 nitrous oxide: 50 oxygen) breathed via mask PRN
Indication - used before or in conjunction with opioids
Advantage - easy to use and minimal accumulation of drug
- no uterine effect
Disadvantage - not complete analgesia
- drowsiness, disorientation and nausea when wearing mask
Discuss pain management of epidural
- go into epidural space Indication - 1st line Contraindication - patient cannot sit still - raised ICP - infection at site or systemic - coagulopathy Complications - early: failure, bleeding, dura puncture, urinary retention - late: post-dural puncture headache, nerve injury, infection, hematoma Advantage - most effective - can be transferred to C-section anaesthesia
Discuss pain management of spinal analgesia
- going past dura mater Indication - provide instanenous relief while waiting for epidural Advantage - rapid onset - complete analgesia Disadvantage - delayed verification of epidural - require dural puncture - risk of fetal bradycardia
Discuss the definition, pathophysiology, and presentation of preterm labour
- labour occurring between 20 and 37 weeks
Pathophysiology - have irritation of the chorion and decidua which triggers uterine contractions and cervical changes
Presentation - uterine contractions with cervical changes
- abdominal pain and pressure
- increase or change in vaginal discharge
List the medications used in pre-term labor
Tocolytics (prolong the latent phase of labour in order to delay delivery by 2-3 days)
- NSAID Indomethecin 50-100mg PO
- MgS04 6g IV loading dose (used in fetus 24-28 weeks due to neuroprotective effect)
- Nifedipine 20mg PO
Corticosteroids
- betamethasone 12mg IM
- done to promote lung maturation and increase surfactant production
List the risk factors for pre-term labor
Maternal - prior history of pre-term labor - low maternal weight - smoking, substance use - short interval between pregnancies Pregnancy - pre-term uterine contraction or rupture of membranes - vaginal bleedng - periodontal disease
List the risk factors for pre-term premature rupture of membranes
- rupture of membrane before 37 weeks and prior to onset of labour Maternal - smoking - prior PPROM - short cervical length Pregnancy - polyhydramnios - multiple gestations - bleeding in early pregnancy
List the risk factors for premature rupture of membranes
- rupture of membranes prior to labour Maternal - multi-parity - cervical incompetence - infection - poor nutrition - family history Pregnancy - congenital anomaly - multiple gestation
Discuss the presentation and management of premature rupture of membranes
Presentation
- fluid gush or continued leakage
- speculum show pooling of fluid in posterior fornix or fluid leaking from cervix
- positive nitrazine test
- most go into labour within 1 week
Complications
- chorioamniotis
- cord prolapse
- limb contracture
Management
- if intra-uterine safer than NICU than expectant managmenet
- near term or term deliver by induction or C-section, with GBS prophylaxis
- pre-term expectant management and IV abx (corticosteroids if less than 31 weeks)
List the Indications and Contra-indications for induction of labour
Indications - post-date pregnancy where >41+3 weeks - gestational hypertension or maternal comorbidities - antepartum hemorrhage - chorioamnionitis - PROM - fetal IUGR Contra-indications - prior C-section - active maternal genital herpes - invasive cervical cancer - placenta previa or cord presentation - fetal distress
List the components of Bishop’s score
Score
- position
- consistency
- effancement
- dilatation
- station
Induction
- >6 than can consider induction as cervix is favourable
List the techniques used for induction of labour
Cervical Ripening (soften, effce, dilate the cervix)
- intra-vaginal PGE2 gel
- foley catheter to manually dilate cervix
Amniotomy
- artificial rupture of membranes to stimulate prostaglandin synthesis and secretion
Oxytocin
- causes uterine contraction allowing for progression of labour
- 10 units in 1L of NS at 0.5-2mU/min to increasing
List the indications and contra-indications for operative vaginal delivery
Indications - fetal distress - medical complications for mother to not push - inadequate progress with adequate uterine activity Contra-indication - incomplete cervical dilatation - unengaged head - non-vertex position - fetal coagulopathy
Discuss the procedure for operative vaginal delivery (ABCDEFGHIJ)
A: Address consent, anesthesia, and assistance
B: Bladder empty
C: Cervix fully dilated, membranes ruptured, contractions adequate
D: Determine fetal position, station and dystocia
E: Equipment check
F: Flexion point for vacuum
G: Gentle mental traction over the posterior fontanelle
H: handle in axis of birth canal, halt (3 pop offs or 3 pulls with no progress after 20 minutes)
I: incision
J: remove when jaw is reachable
List the grading system for perineal tears
1st Degree
- involvement of the fourchette, perineal sin and vaginal mucosa
2nd Degree
- involvement of 1st degree plus fascia and muscles (bulbocavernosus, perineal body, and transverse perineal muscle)
3rd Degree
- involvement of above plus extension into anal sphincter
4th Degree
- involvement of above plus extension into rectal mucosa
Discuss the indications for surgical repair of perineal tears
Indication
- perineal laceration >=2nd degree
List the indications for a C-section
Maternal - obstruction in birth canal - active herpetic lesion - invasive cervical cancer - previous uterine surgery - underlying maternal illness Pregnancy - failure to progress - placental abruption, previa - vasa previa - umbilical cord prolapse Fetal - abnormal fetal heart tracing - malpresentation - cephalic pelvic position - congenital anomaly
List the risks of C-section
- anesthesia risk
- hemorrhage
- injury to surrounding bowel, bladder, ureter or uterus
- thromboembolism
- increased recovery time
What is vaginal birth after cesarean and what are the contraindications
- usually done after previous low transverse uterine incision
Contraindication - previous classical or unknown incision with risk of possible rupture
- previous uterine rupture
- multiple gestation
- estimated fetal weight >4kg
- non-vertex position
Define dystocia
- abnormal labour progress when cervix dilated >3-4cm
1st phase - protracted cervical dilatation <1.2cm/hr in nulli or <1.5cm/hr in multi
- arrest of dilatation >2hours in nulli or multi
2nd Phase - protracted descent <1cm/hr in nulliparous or <2cm/hr in multi
- arrest of descent >1hr in nulli and multi
Due to 3 primary causes
- power: ineffective uterine expulsive forces
- passenger: abnormal fetal lie, malpresentation, fetal anatomic defect, macrosomia
- passage: maternal bony pelvic contracture
Discuss the causes of Passenger abnormalities
Mal-presentation
- breech: buttock or feet first
- brow: brow of face
- face: face first
- shoulder
- compound presentation: extremity prolapse with transverse lie
Management
- breech: external cephalic version before labour or C-section
- face presentation: mentum anterior can be delivered
- brow presentation: wait for conversion to face or cephalic, if not C-section
- shoulder: C-section
- compound: retraction and then normal delivery
Discuss the presentation and management of breech presentation
Definition
- complete: flexion at hip and knees (least common)
- frank: flexion at hips and knees extended (most common)
- footling: foot as presenting with extension at hip and knee
Risk Factors
- maternal: abnormal uterine shape or pelvic contraction
- pregnancy: previa, polyhydramnios, prematurity, multiple gestation
Management
- ultrasound
- external cephalic version if >37 weeks, head not engaged and unreactive stress test
- delivery: vaginal only if perfect criteria (>36 weeks, weight between 2.5-3.8, fetal head flexed, continuous monitoring and ability to perform crash C-section) otherwise perform C
Discuss the passage complications
- cephalopelvic disproportion: maternal bony pelvis is not sufficient
Pelvic Inlet Contraction - shortest anteroposterior diameter if diagonal conjugate <11.5 (1.5cm greater than obstetric conjugate)
Mid-Pelvic Contraction (most common) - palpation of ischial spines where <10cm is suspected as cause and <8cm is known
Pelvic Outlet Contraction (least common) - inter-ischial tuberous diameter of <8cm
Discuss the power complications
- uterine dysfunction: lack power to push fetus through birth canal
- hypotonic when synchronous effort but insufficient pressure to dilate cervix
- hypertonic where have elevated base tone of uterus
- incoordinate where distorted pressure gradient in uterus
Etiology - maternal position
- epidural analgesia
- chorioamnionitis
- uterine abnormality
Management - augementation of labour through amniotomy and oxytocin
Discuss the presentation and management of Shoulder Dystocia
Pathophysiology
- impaction of anterior or posterior shoulder during vaginal delivery
Risk Factors
- pre-labour: macrosomia >4.5kg, history of shoulder dystocia, induction of labour
- intra: prolonged first and second stage, secondary arrest, oxytocin augmentation, assisted vaginal delivery
Diagnosis
- difficulty delivering head and chin
- head remaining tightly in vulva and retracting
- failure to restitute fetal head
- failure of shoulder to descend
- head to body delivery >60 seconds
Management
- call for help and discourage pushing
- McRobert’s maneuver: sharp flexion of mothers leg onto abdomen with suprapubic pressure
- episiotomy
- Woods maneuver: progressive rotation of posterior shoulder 180 degrees
- deliver posterior shoulder
- second Rubin maneuver
List the complications from shoulder dystocia
Maternal - 3rd-4th degree perineal tears - post-partum hemorrhage - infection - uterine rupture - fistual Fetal - brachial plexus injury - clavicle or humerus fracture - fetal death
List the definition and risk factors for post-partum hemorrhage
Definition: - >500mL of blood loss with vaginal delivery or >1000mL with C-section - any blood loss which results in hemodynamic instability Risk Factors - failure to progress in second stage - adherent placenta - family history - Asian or hispanic - instrumental delivery - large for gestational age baby - hypertensive disorder - obesity - multiple gestation
Discuss the differential for PPH
Tone (most common)
- pathophysiology: failure of uterus to contract and involute post-delivery resulting in early (<24hrs) PPH
- labour: prolonged, induced, augmentated
- uterus: infection, over-distention, functional disorder
- placenta: abruption, previa
- grand-multiparity
Tissue
- pathophysiology: retained tissue within uterus preventing from involution
- placental or clots retained
Trauma
- pathophysiology: trauma to any part of female anatomy
Thrombin
- pathophysiology: disruption of platelet plug formation or coagulation cascade
Discuss the management of PPH
Stabilize and Monitor Medical: - Oxytocin 20units/L NS continuous - add Methylergonavine maleate, carboprost, misoprostil, or 15-methyl prostaglandin Source control - remove retained products - close laceration or add compression Invasive - B-lynch suture: compression of atonic uterus - internal iliac ligation - hysterectomy
Discuss the post-partum management for contraception
- OCP not recommended for first 3-6 weeks following delivery for non-breast feeding mothers due to risk of VTE
- can ovulate within 25 days post-partum so require immediate protection
- breast feeding mothers anovulation <6 months, breast feeding exclusively, and amenorrhea.
- Initially condoms or IUD recommended as progesterone does not affect milk production.
Discuss the post-partum management of depression
Presentation
- blues increase 3-5 days post-partum and improve after few weeks
- depression in onset of depressive symptoms within 3 months post-partum
Prevention
- lifestyle modification in order to reduce stress
Treatment
- SSRI
- psychosis get CBT
Discuss nutrition and alcohol post-partum
- require increased calories in breastfeeding women with good iron and calcium intak
- gradual post-partum weight loss of <4.5lbs/month
Discuss effects of smoking and alcohol use post-partum
Smoking - SIDS - lung disease - learning disorder Alcohol - decreased milk intake - impaired motor development - altered sleep
Discuss appropriate breastfeeding guidelines
Recommendations - should breastfeed for first 6 months exclusively - feed 8-12x per day with 6-8 wet diapers and one soft, seedy stool Contraindications - HIV positive - HTLV - Herpes lesion of breast - Child with galactosemia - Drugs use in mother
Discuss the risk factors for intra-uterine fetal death
- is fetal death after 20 weeks or if weight >500g Maternal - advanced maternal age - prior stillbirth - post-term - obesity - smoking or illicit drug use Pregnancy - fetal growth restriction - fetal macrosomia - multiple gestation - no antenatal care
Discuss the presentation and management of intra-uterine fetal death
Presentation - decreased fetal movements - uterine contraction - vaginal bleeding - symphysis-fundal height no increasing Investigations - high AFP - absent cardiac activity - secondary analysis for cause - possible DIC Management - spontaneous labour and vaginal delivery - induced labour - dilatation and evacuation for 18-24 weeks
Discuss the medical management of termination of pregnancy
Medical Management
- Fetus <9 weeks: Methotrexate plus misoprostol
- Fetus >12 weeks: prostaglandin or misoprostol
- require good follow up care
Surgical Management
- <12-14 weeks dilatation and curettage
- >12-14 weeks: dilatation and evacuation
