Obstetrics Flashcards
Labour definition
Regular painful uterine contractions causing progressive cervical dilatation and effacement
Most people don’t consider it to be true labour unless there is 4 cm of dilatation
Characteristics of true and false labour
True
- Regular uterine contractions
- Decreasing interval
- Increasing pain
- Cervical dilatation
- Sedation does not change contraction pattern
False
- Irregular uterine contractions
- Variable interval
- Unchanged intensity
- No cervical change
- Sedation decreases contraction pattern
Labour progress
Nullip
- Latent phase should be <24h
- Cervical dilatation should occur at 1.2 cm/h
- Second stage should be <2h, <3h with epidural
Multip
- Latent phase should be <8-12h
- Cervical dilatation should occur at 1.5 cm/h
- Second stage should be <0.5 h, <1.5 h with epidural
Cardinal Movements
- Engagement
- Descent
- Flex ion
- Internal rotation
- Extension
- External rotation (restitution)
- Expulsion (anterior and then posterior shoulder)
What are the 4Ps that determine the occurrence of dystocia
Power
Passenger
Passage
Psyche
How many eggs are females born with?
5 000 000 primordial follicles at 20 weeks
200 000 eggs at birth
1000 primordial follicles to make a mature one in one ovulatory cycle, which occurs 12-13 times per year with menstruation
Menopause definition
Permanent cessation of menstruation >12 months of amenorrhea
Mean age 51 yo
Menopause pathophysiology and presentation
Estrogen deficiency
Vast motor sx (hot flashes) Urogenital atrophy and dryness Sexual dysfunction Insomnia Weight gain
LH and FSH >40 IU/L
Most common malignancies in women
- Lung
- Breast
- Colorectal
- Endometrial
Normal duration labour stage 1
Latent phase Nulliparous: - Mean 6.5h - Longest normal 20h Multiparous - Mean 5h - Longest normal 13.5h
Active phase rate Nulliparous: - Mean 3 cm/h - Slowest normal 1.2 cm/h Multiparous: - Mean 6 cm/h - Slowest normal 1.5 cm/h
Normal duration labour stage 3
Usually within 30 minutes
Labour definition
Painful, regular uterine contractions with cervical dilation
Most people consider this dilation minimum to be 4 cm
Normal labour criteria
- Begins spontaneously
- Proceeds at normal rate (according to Friedman curve)
- Proceeds without intervention
- Results in spontaneous vaginal delivery of a healthy infant
Active management of 3rd stage of labour
- If failure to deliver placenta by 30-45 minutes
- prevents PPH
- Includes uterotonics (Oxytocin), controlled cord traction and uterine massage
- After delivery of placenta, clamp and cut cord
Delayed cord clamping benefits and contraindications
- If preterm delay cord clamping for at least 1 minute to infuse more iron and blood into fetus for improved outcome (less IVH, decreased need for transfusion)
- If thick meconium immediate clamping for prompt possible resuscitation
How to interpret fetal auscultation
Fetal heart tone audible starting at 20 weeks gestation
Listen with stethoscope, pinnard horn, fetoscope or Doppler on abdomen best at baby’s back for 1 minute while palpating maternal radial pulse before and after uterine contraction
Labour definition
Painful, regular uterine contractions with cervical dilation
Most people consider this dilation minimum to be 4 cm
Normal labour criteria
- Begins spontaneously
- Proceeds at normal rate (according to Friedman curve)
- Proceeds without intervention
- Results in spontaneous vaginal delivery of a healthy infant
7 cardinal movements
- Engagement - head at level of ischial spine
- Descent - downward passage through bony pelvic
- Flexion - partial flexion of head as baby descends through pelvis due to shape of bony pelvis
- Internal rotation - rotation of head from occiput transverse to anterior or posterior
- Extension - extension of head once past pubic symphysis
- Restitution (external rotation): when head is completely delivered, it rotates back to original position prior to internal rotation, realigning with fetal torso
- Expulsion - further descent brings shoulder to pubic symphysis followed by release of anterior then posterior shoulder and rest of fetus
All cardinal movements are accompanied by descent
Normal presentation and position
Cephalic vertex and occiput anterior
4 cardinal questions
- Fetal movement (normal >6 movements in 1 hour)
- Bleeding per vagina
- Rupture of membrane
- Contractions including regularity and pain
Differentiating false and true labour
In true labour contractions are regular, interval between decreases, worsening intensity/pain, back and abdomen location (vs lower abdomen for Braxton Hicks), dilating cervix, no change on contraction with sedation
Differentiating false and true labour
In true labour contractions are regular, interval between decreases, worsening intensity/pain, back and abdomen location (vs lower abdomen for Braxton Hicks), dilating cervix, no change on contraction with sedation
What is station
Vertical distance in cm from presenting part relative to maternal ischial spine
Negative = above
Positive = below
Indications to start pushing
- Exceeded 3rd hour of stage 2 labour
- Patient without epidural feels urge to push
- In patient with epidural urge to push or head is visible or station >+2 and OA, ROA, LOA
Maximum duration of pushing
Reassess after 2h of active pushing for operative vaginal delivery if nullparous or multiparous with epidural
Reassess after 1h of active pushing for multiparous patient without epidural
Earlier reassessment if maternal or fetal status is concerning
Dystocia
- Protracted descent <1 cm/h in nulliparous women
- <2 cm/h in multiparous women
- Arrest of descent >1h
Types of placentation with multiple pregnancy
Mono or dichorionic
Mono or diamniotic
Any combination of the above
Types of placentation with multiple pregnancy
Mono or dichorionic
Mono or diamniotic
Any combination of the above
Normal uterine contraction qualities
Frequency normally 0-5 in 10 minutes and not more than every 2 minutes
Duration normally <90 seconds
Resting time >30 seconds in between contractions
Timing regular singular
Indications for fetal scalp sampling
- Atypical or abnormal fetal tracings where delivery is not imminent
- Digital fetal scalp stimulation does not result in acceleration
Contraindications for fetal scalp sampling
- Gestation <34 weeks
- High risk of bleeding
- Face presentation
- Maternal infection (HIV, hepatitis, herpes simplex, intrauterine sepsis)
Sinusoidal variability
Variability following a sinusoidal pattern of regular peaks and troughs
Tachycardia and bradycardia
> 160 bpm or <110 bpm for 10+ minutes
Tachycardia and bradycardia
> 160 bpm or <110 bpm for 10+ minutes
Complicated variable deceleration
<70bpm lasting >1min
Biphasic deceleration
Prolonged secondary acceleration (overshoot >20 bpm and/or lasting >20 seconds)
Slow return to baseline
Continuation of baseline rate at lower rate than prior to deceleration
Presence of fetal tachy or bradycardia
Repetitive deceleration
> 3 episodes of deceleration
Late deceleration
Gradual decrease in fetal heart rate and return to baseline heart rate reaching nadir in 30+ seconds after contraction
Early deceleration
Gradual decrease in fetal heart rate and return to baseline heart rate reaching nadir in 30+ seconds before contraction
Usually a mirror image of contraction
Prolonged deceleration
deceleration >15 bpm below baseline lasting 2-10 minutes from beginning to return to baseline
Classification of fetal monitoring
Chart pg 38 Tony’s
Purpose of fetal scalp blood sampling
Determine if baby should be delivered immediately based on blood pH
Interpretation of fetal scalp blood
pH >7.25 - continue observation or repeat sampling within 30 minutes if persistent atypical or abnormal fetal monitor pattern
pH 7.21-7.24 - repeat within 30 mins or consider delivery if rapid fall since last sample
pH 0-7.2 - immediate delivery
see Tony’s for practice cardiotocography
pg 39
CSE definition
Combined spinal epidural analgesia
CSE indication
Provide instantaneous pain relief with spinal analgesia while waiting for onset of epidural analgesic effect, such as in early labour, late first stage labour or rapid progress of labour
What are the main differences between spinals and epidurals?
- Location of injection
- Spinals last for a shorter period of time
- Spinals provide stronger analgesia effect
- Spinal has larger risk of PDPH, pruritus, fetal bradycardia, limited analgesia duration in single shot spinal analgesia
Regional pudendal nerve block procedure
Insertion of local anesthesia using needle through vagina to pudendal nerve (S2-4)
Regional pudendal nerve block role
Only provide pain relief for perineum
Regional pudendal nerve block indication
Spontaneous use of outlet forceps or spontaneous vaginal delivery
Regional pudendal nerve block disadvantages
- High risk of local anesthesia toxicity, laceration, hematoma, fetal injury
- Often inadequate pain relief for delivery, repair of vagina and cervix and manual exploration of uterine cavity
Para-cervical block indication
1st stage of labour
Para-cervical block procedure
Needle inserting local anesthesia into vaginal fornices
Para-cervical block disadvantages
Risk of fetal bradycardia, fetal injury
Perineal infiltration indication, procedure and advantages
- Indication - commonly used for vaginal delivery
- Procedure - needle injecting local into posterior fouchette (posterior to vagina) to freeze perineum
- Advantage - rapid onset
Pre-term labour diagnosis, signs and symptoms
Pre term labour is a clinical diagnosis based on active labour of painful regular uterine contractions (2 in 10 minutes) with signs of cervical changes (dilation and effacement)
- Menstrual like cramps
- Low, dull backache
- Abdominal pressure, cramping, +/- diarrhea
- Pelvic pressure
- Uterine contraction, often painless
- Increase or change in vaginal discharge (mucous, watery, light bloody)
- Pelvic exam (cervical effacement >80%) or dilatation >2cm or change in cervix
- Speculum exam ROM
Pre-term labour definition
labour occurring at 20-37 weeks GA
Processes proposed in the pathogenesis of pre-term labour
Remains unknown. Proposed:
- Irritation of chorion and decidua by stress, infection, abruption, uterine distention
- Irritation triggers uterine contractions and cervical changes (release of proteases cause cervical change and ROM, release of uterotonins cause uterine contraction)
- Uterine contractions and cervical changes result in pre-term labour and delivery
Management plan for pre-term labour
- Initial - hydration, bed rest
- U/S assessment of fetus
- Abx therapy (may decrease maternal infection risk if intact membranes, definitely indicated if ROM)
- Suppression of labour
- tocolysis, usually <48h
- 1st line Indomethacin or Nifedipine
- 2nd line MgSO4 - Enhance fetal pulmonary maturity with corticosteroids
- Cervical cerclage
Pre-term labour definition
labour occurring at 20-37 weeks GA
Tocolytic in pre term labour goal and risks
- prolongs latent phase labour and delay delivery by goal of 3 days, which allows administration of 2 doses corticosteroids for maturation of lungs, thereby improving outcomes of premature babies once delivered
- Risks - narrow therapeutic index with many side effects
NSAID in pre term labour contraindication, MOA, maternal SE, fetal SE, newborn SE
a) NSAID Indomethacin
- Most commonly used tocolytic
- Contraindication: maternal platelet dysfunction, bleeding idsorder, hepatic dysfunction, GI bleed, renal failure, asthma
- MOA: inhibition of conversion of free arachidonic acid to prostaglandin –> decreased prostaglandin –> decreased uterine contraction
- Maternal SE: nausea, esophageal reflux, emesis, gastritis, platelet dysfunction
- Fetal SE: in utero constriction of ductus arteriosus, oligohydramnios
- Newborn SE: NEC, PDA
MgSO4 in pre term labour indication, maternal contraindication, MOA, maternal SE, newborn SE
b) MgSO4
- Indication: fetus 24-28 weeks due to neuroprotective effects
- Maternal contraindication: myasthenia gravis
- MOA: compete with calcium for entry into muscle cells –> decreased uterine contraction
- Maternal SE: flushing, diaphoresis, nausea, loss of deep tendon reflexes, respiratory depression, cardiac arrest especially combined with CCB
- Newborn SE: neonatal depression
Nifedipine in pre term labour maternal contraindication, MOA, maternal SE
c) CCB Nifedipine
- Maternal contraindication: hypotension, AR
- MOA: block Ca entry into muscle cells –> decreased uterine contraction
- Maternal SE: dizziness, flushing, hypotension, bradycardia, decreased cardiac output
Beta adrenergic receptor in pre term labour agonist maternal contraindication, moa, maternal se, fetal se
d) Beta-Adrenergic Receptor Agonist
- Maternal contraindication: Tachycardia sensitive maternal cardiac disease, poorly controlled maternal diabetes
- MOA: increase cAMP concentration –> decreased Ca in muscle cell –> decreased uterine contraction
- Maternal SE: tachycardia, hypotension, tremor, SOB, angina, pulmonary edema, hypokalemia, hyperglycemia
- Fetal side effects: fetal tachycardia
Corticosteroid in pre term labour examples, MOA, maternal contraindications
Betamethasone (Celestone), Dexamethasone
MOA: unknown, promotes lung maturation and increases surfactant production, thereby reducing severity of RDS, rate of IVH and mortality of premature newborn
Maternal contraindications: active TB, viral keratosis, DM
Tocolytics in pre term labour management indications and contraindications
Indications If all of the following are satisfied: - Live immature fetus - Intact membrane - Cervical dilatation <4cm - Absence of maternal or fetal contraindications
Contraindications
- Maternal bleeding from placental previa or abruption
- Maternal disease: hypertension, DM, heart disease, pre-eclampsia, eclampsia, chorioamnionitis
- Fetus: erythroblastosis fetalis, severe congenital anomalies, fetal distress/demise, IUGR, multiple gestation
Cervical cerclage definition
Placement of cervical sutures, wires or synthetic tape at internal os to close cervix
Cervical cerclage indications
Primary structural abnormality of cervical incompetence (cervical dilatation and effacement in absence of uterine contractility)
Premature rupture of membranes signs and symptoms
- fluid gush or continued leakage per vagina
- Speculum exam
a) pooling of fluid in posterior fornix
b) fluid leaking out of cervix on cough or Valsalva (“cascade”)
PROM diagnostic investigations
- Positive nitrazine test: basic amniotic fluid turns nitrazine paper blue, which can be positive with blood, urine or semen
- Fluid ferning on microscopic slide
- Ultrasound - decreased amniotic fluid volume suggests ROM
- If PPROM amniocentesis for lecitin/spingomyeline (L/S) ratio to assess lung maturity
Factors predisposing to PROM
- Maternal
- Multi-parity
- Cervical incompetence
- Infection
- Family history of premature rupture of membrane
- Poor nutrition, low SES - Current pregnancy
- Congenital anomaly
- Multiple gestation
Risks and benefits of expectant management vs immediate delivery of patient with PROM
Expectant management
- may buy time for fetus to mature
- prolongs elapse from ROM to delivery thereby increasing risk of chorioamniotis and sepsis
Immediate delivery
- Shortense elapse from ROM to delivery (decrease risk chorioamniotis and sepsis)
- Shortens time for fetus to mature in case of premature, increasing risk of complications especially RDS
Pre-term premature ROM (PPROM)
ROM before 37 weeks gestation and prior to onset of labour
Prolonged rupture of membrane
Elapse of >24h from ROM to onset of labour
PPROM risk factors
- Maternal
- Smoking
- Prior PPROM or pre-term delivery
- Short cervical length - Current pregnancy
- Polyhydramnios
- Multiple gestations
- Bleeding in early pregnancy (threatened abortion)
PROM complications
- Chorioamniotic –> maternal or fetal sepsis, cord prolapse, limb contracture
Management of PROM
1
b) . If intra-uterine environment safer than NICU –> expectant management and wait for spontaneous delivery
2. Monitoring and investigations
- admit
- daily CBC and BPP (biophysical profile) by ultrasound
- avoid bimanual to avoid introducing infection
- culture urine and genital tract (lower vagina for GBS and cervix for Gonorrhea and Chlamydia)
3. a) 34+ weeks: delivery by induction of labour or CS, GBS prophylaxis unless negative swab within 5 weeks
b) 32-33 weeks: expectant management, GBS prophylaxis, IV abx prophylaxis to prolong latency if no contraindication
c) 24-31 weeks: above + corticosteroid for lung maturation, tocolytics may be considered if ROM trigger pre-term labour
d) <24 weeks: consider termination, expectant management or induction, GBS prophylaxis, IV antibiotic prophylaxis not indicated
GBS prophylaxis
Single dose Penicillin G or Ampicillin at ROM
Indications for GBS pophylaxis
- GA<37 weeks
- Positive swab GA 35-37 weeks
- Prior history of GBS infected infant
- GBS bacteriuria
Antibiotic prophylaxis in PROM
Ampicillin and Erythromycin x 48h
Followed by Amoxicillin and Erythromycin x 5 days
What does antibiotic prophylaxis in PROM do?
Increases time from PROM to onset of labour by 5-7 days with no increase in maternal or neonatal morbidity or mortality
Indication for antibiotic prophylaxis
Expectant management where immediate delivery is not indicated (ex. fetal distress, chorioamniotis)
Indication for labour induction
Risk of continuing pregnancy exceeds risk of induced labour and delivery or post date pregnancy (>41+3)
Contraindication for labour induction
most are indications for C section and contraindications for spontaneous delivery
Maternal - prior classicla or inverted T C section or uterine surgery, unstable maternal condition, cephalicpelvic disproportion, active maternal genital herpes,invasive cervical cancer, pelvic structure deformity
Pregnancy - placenta previa, vasa previa, cord presentation
Fetus- fetal distress, malpresentation, pre-term fetus with immature lung
Pre-requisit for labour induction
- Capability for C section if necessary
- Short, thin, soft anterior cervix with open os (“inducible” or “ripe”)
- Normal fetal heart tracing, cephalic presentation and adequate fetal monitoring available
You have a patient that you want to induce, but the cervix is not ripe. What are your next steps
Prostaglandin vaginal insert, prostaglandin gel or Foley catheter
What is Bishop’s score
Pre-labour scoring system to likelihood of entering labour naturally and also success of induction of labour
You have a patient that you want to induce, but the cervix is not ripe. What are your next steps
- Prostaglandin vaginal insert (Cervidil)
- Intra-vaginal prostaglandin gel (Prostin gel)
- Foley catheter
- Hydroscopic dilator or osmotic dilator
- Synthetic methlyated PGE1 Misoprostol (not usually used)
Bishop’s score interpretation
<6 - low chance of entering labhour in the near future and cervix is unfavourable for labour induction
6+ - good chance of entering labour in the near future and cervix is favourable for induction
9+ - very good chance of entering into active labour in the near future for vaginal delivery
What is not effective in ripening cervix
Oxytocin
Indication for Cervidil insert
Long and closed cervix, and may be used in ruptured membrane
Amniotomy purpose
Artificial rupture of membrane to stimulate prostaglandin synthesis and secretion
Amniotomy indication
Unruptured membrane
Amniotomy purpose
Artificial rupture of membrane to stimulate prostaglandin synthesis and secretion (induction or augmentation)
Oxytocin complications
Hyperstimulation/tetanic uterine contraction, which may lead to fetal distress or uterine rupture
Uterine muscle fatigue and atony, which may lead to PPH
Vasopressin-like action causing anti-diuresis
Oxytocin purpose
Cause uterine contraction, facilitating progression to active labour (induction or augmentation)
Oxytocin complications
Hyperstimulation/tetanic uterine contraction, which may lead to fetal distress or uterine rupture
Uterine muscle fatigue and atony, which may lead to PPH
Vasopressin-like action causing anti-diuresis
Indications for operative vaginal delivery
- Fetal distress, based on abnormal or atypical fetal heart monitoring
- Medical indication for mother to avoid pushing/valsalva (ex. cardiac disease, CVD)
- Inadequate progress (ie dystocia) with adequate uterine activity and no evidence of cephalopelvic disproportion
Contraindication of operative vaginal delivery
- Incomplete cervical dilatation
- Unengaged head
- Non-vertex presentation including brow presentation
- Clinical evidence of cephalopelvic disproportion
- Fetal coagulopathy
- Vacuum is contraindicated in premature baby gestational age <34 weeks
Use of forceps vs vacuum
- Forceps often used for rotation
- Forceps can be used for mid to low station (0 to +3)
- Vacuum used only for low station (+3 or greater)
- Can use either, but never both!
Operative vaginal delivery general procedure
A - address consent, anesthesia, assistance for delivery and neonatal resuscitation, absence of contraindication
B- bladder empty
C- cervix fully dilated, membranes ruptured, contractions adequate
D - determine fetal position, fetal station, pelvic adequacy, dystocia consideration
E - equipment check
F- flexion point for vacuum, forceps position for safety
G - mental traction with (forceps or vacuum) with uterine contraction and pushing
H- handle (traction in axis of birth canal for forceps); halt (stop vacuum if 3 pop-offs or after 3 pulls with no progress or after 20 minutes; stop either instrument after 20 minutes of trying)
I - incision (episiotomy if needed)
J - remove vacuum or forceps when jaw is reachable or delivery assured
Risk of complications with operative vaginal delivery
Maternal - laceration (forceps higher risk than vacuum), hematoma, perineal tears
Fetal
- Trauma to head (scalp lac, bleeding, skull fracture, cephalohematoma, sub-aponeurotic hemorrhage (aka subgaleal hemorrhage), ICH, retinal hemorrhage, facial nerve palsy
- Trauma elsewhere (shoulder dystocia)
Difference betwen cephalohematoma and sub-galeal hemorrhage
Cephalohematoma does not cross suture lines
Sub-galeal hemorrhage crosses suture lines and causes rapid increase in head circumference
Next step if failure of operative vaginal delivery
C-section
Grading of perineal laceration
1st degree - involvement of fourchette, perineal skin and vaginal mucosa, but no involvement of underlying fascia and muscle
2nd degree- 1st degree + involvement of fascia and muscles including bulbocavernosus, perineal body, transverse perineal muscle, but not anal sphincter
3rd degree - 2nd degree + extension to involve anal sphincter, but does not extend through rectal mucosa
4th degree - 3rd degree + extension through rectal mucosa
Surgical repair of perineal laceration indication
- Perineal laceration 2nd degree+ requires surgical repair with suture (1st degree may be, but not necessary)
Surgical repair of perineal laceration procedure
- Lidocaine, irrigation, consider cephalosporin
- Closure of rectal mucosa and external anal sphincter
a) Identify and incorporate apex of rectal mucosal tear
b) rectal mucosa is approximated using closely interrupted or running stitch, do not go complete thickness of mucosa into anal canal to avoid formation of fistula
c) Suture continued to anal verge (ie onto perineal skin)
d) Closure of internal anal sphincter by continuous stitch
e) Re-approximate and close external anal sphincter with interrupted sutures by end-to-end technique or overlapping technique (brings together ends of sphincter with mattress sutures)
f) Post repair, put finger through rectum to ensure no stitch can be palpated in rectal mucosa - Intermittent or continuous suture of perineal body and bulbocavernosus
a) After closing vaginal incision and re-approximating cut margins of hymenal ring, need, suture positioned to close perineal incision
b) perineal body and bulbocavernosus muscle reapproximated with intermittent or continuous suture, where intermittent suture can hold repair in place even if one suture breaks
c) Suture then carried upward as subcuticular stitch to approximate superficial fascia and skin overlying bulbocavernosus and perineal body - Continuous closure of vaginal mucosa and submucosa
a) Identify and incorporate apex of tear in repair
C section indications
Maternal
- Birth canal - obstruction, active herpetic lesion, invasive cervical cancer
- Previous uterine surgery
- Underlying maternal illness - pre-eclampsia, eclampsia, HELLP syndrome, heart disease
Pregnancy complications
- Failure to progress
- Placental abruption, placenta previa
- Vasa previa
- Umbilical cord prolapse
Fetal complications
- Abnormal fetal heart tracing
- Mal-presentation
- Cephalic pelvic disproportion
- Certain congenital anomalies
Types of C section incisions and their benefits, risks or indications
- Vertical - rapid peritoneal entry, increased exposure, increased risk of dehiscence
- Transverse - slower entry, decreased exposure, improved wound strength and cosmesis
- Low transverse -in non-contractile segment to decrease chance for rupture in subsequent pregnancies (most common incision used)
- Low vertical for very pre-term infants or poorly developed maternal lower uterine segment
- Classical incision in thick contractile uterine segment for transverse lie, fetal anomaly, >2 fetuses, lower segment adhesion, obstructing fibroid (rarely used)
Maternal mortality rate with CS
<0.1%
VBAC stands for
Vaginal Birth After Cesarean
What’s the deal with VBAC
Recommended vaginal delivery after previous low transverse uterine incision (success usually 60-80%, risk of uterine rupture 1/200)
VBAC contraindication
- Previous classical, previous inverted-T, previous unknown uterine incision, previous complete transection of uterus, which have 6% risk of uterine rupture
- Previous uterine rupture
- Multiple gestation
- Estimated fetal weight >4 kg
- Non-vetex presentation or placenta previa
- Inadequate facilities or personnel for emergency CS
Dystocia definition
Abnormal labour progress, defined as the following in women in active labour with cervix dilated >3-4 cm
1. 1st phase (active phase): protracted cervical dilatation <1.2cm/hr in nulliparas women, <1.5cm/hr in multiparas women 1st phase (active phase): arrest of dilatation >2 hours in nulliparas and multiparas women
- 2nd phase: protracted descent <1cm/hr in nulliparas women, <2cm/hr in multiparas women
2nd phase: arrest of descent >1 hour in nulliparas and multiparas women
(2nd stage usually limited to 2 hours (or 3 hours with regional analgesia) in nulliparas women; and 1 hour (or 2 hours with regional analgesia) in multiparas women
protracted disorder in dystocia
slower than normal progress
arrested disorder in dystocia
complete cessation of progress
Dystocia pathophysiology
dystocia can be due to power, passenger and / or passage (3 Ps)
1) Power = ineffective uterine expulsive forces
2) Passenger = abnormal fetal lie, malpresentation, malposition, fetal anatomic defect, macrosomia
3) Passage = maternal bony pelvic contracture
Power, passenger and passage can contribute to failure to progress or cephalopelvic disproportion
dystocia is most commonly failure to progress, because there are very few cases of true cephalopelvic disproportion
Failure to progress
lack of progressive cervical dilatation or lack of fetal descent
What does fetus position refer to
Orientation of baby’s head relative to birth canal
Normal fetal position
occipitoanterior (OA), which is baby’s occiput (posterior head) is oriented to anterior
Normal lie of fetus
Longitudinal (long axis of fetus parallel to long axis of mother)
Management of breech presentation
external cephalic version (manual converting breech fetus to vertex presentation) before labour; C-section
Management of face presentation
mentum anterior can be delivered with descent, internal rotation, flexion, extension and external rotation; C-section
Management brow presentation
wait for conversion to face presentation or cephalic vertex presentation; if persist, then C-section
Management shoulder presentation
spontaneous delivery is impossible, so C-section
Management compound presentation
usually does not interfere with labour, may attempt gentle retraction if preventing progress
Management occiput transverse
manual rotation or forceps (Kielland) rotation and delivery
Management occiput posterior
observe for spontaneous change to OA; if persistent consider forceps or manual rotation
Types of breech
Complete breech - flexion at hips and knees
Frank breech (most common) - flexion at hips and extension at knees
Footling presentation - foot as presenting part with extension at hip and knee
Breech epidemiology
25% of pregnancies before 28 weeks
3-4% pregnancies at term
Breech risk factors
- Maternal
a) Anatomy - pelvis contraction, uterus shape abnormalities, intra/extrauterine masses
b) Ob/Gyn history - grand multiparity - Current pregnancy
- placenta previa
- poly or oligohydramnios
- fetal prematurity
- multiple gestation
- congenital malformation
- abnormality in fetal tone and movement
- aneuploidy
Breech presentation complications
Lower birth weight, higher rate peri-natal mortality, higher risk congenital anomalies, higher risk placental abruption, higher risk cord prolapse
Breech management
1) Ultrasound Assessment
pre or early labour ultrasound assessment to assess type of breech presentation, fetal growth, fetal weight, attitude of fetal head
if ultrasound unavailable, then C-section
2) External Cephalic Version (ECV)
criteria where ECV may be attempted: gestational age >37 weeks, unengaged presenting part and reactive non-stress test
contraindication: previous 3rd trimester bleed, prior classical C-section, previous myomectomy, oligohydramnios, premature rupture of membrane, placenta previa, abnormal
ultrasound, suspected intra-uterine growth restriction, hypertension, uteroplacental insufficiency, nuchal cord
procedure: repositioning of fetus within uterus under ultrasound guidance under continuous cardiotocography
success rate of 65%, higher for multiparous, good amniotic fluid volume, small baby and skilled obstetrician
complication: placental abruption, cord compression
3) Delivery of Baby
delivery of baby can be vaginal delivery or C-section
a) vaginal delivery
criteria where vaginal delivery may be attempted: frank or complete breech presentation, gestational age >36 weeks, fetal weight estimated 2.5-3.8kg on clinical or ultrasound
exam, fetal head flexed, continuous fetal monitoring, 2 experienced obstetrician, assistant and anesthetist, ability to perform emergency C-section within 30 minutes if required
contraindication: cord presentation, clinically inadequate maternal pelvis, fetal anomaly incompatible with vaginal delivery
procedure: encourage maternal pushing effort, assistant apply supraubic pressure to flex and engage fetal head, apply fetal manipulation only after spontaneous delivery to
level of umbilicus
b) C-section
indication: footling presentation, dystocia (failure to descend to perineum in second stage of labour after 2 hours in absence of active pushing or vaginal delivery not imminent
after 1 hour of active pushing), any contraindication for vaginal delivery
Anatomical sites of pelvic contraction
mid-pelvic contraction > pelvic inlet contraction > pelvic outlet contraction
Pelvic inlet contraction
pelvic inlet contraction = shortest anteroposterior diameter, the obstetric conjugate <10cm; greatest traverse diameter <12cm
clinically, obstetric conjugate estimated based on diagonal conjugate (see below), where
pelvic inlet contraction if diagonal conjugate <11.5cm
Mid-pelvic contraction
contracted mid pelvis cause transverse arrest of fetal head in labour
mid-pelvis = obstetrical plane extending from interior margin of symphysis pubis, through ischial spine and touches sacrum near junction of 4th and 5th vertebrae
mid-pelvis transverse line = line connecting ischial spines dividing mid-pelvis into anterior and posterior portions
clinically, mid-pelvis transverse line measured by palpation of bilateral ischial spines during vaginal exam and estimating distance between the 2 spines (interspinous
distance)
mid-pelvis contraction is suspected when inter-spinous distance is <10cm and definitely diagnosed when inter-spinous distance is <8cm
Pelvic outlet contraction
pelvic outlet transverse measured as the distance between the bilateral ischial tuberosity (inter-ischial tuberous distance), which is palpated from external palpation of perineum pelvic outlet contraction = inter-ischial tuberous diameter <8cm
Management of maternal pelvic contraction and cephalopelvic disproportion
C section
Uterine dysfunction definition
uterus lack enough power to push fetus through birth canal
uterine dysfunction can be hypotonic, hypertonic or incoordinate
hypotonic uterine dysfunction = synchronous but insufficient pressure to dilate cervix
hypertonic uterine dysfunction = elevated basal tone of uterus
incoordinate uterine dysfunction = distorted pressure gradient
Uterine dysfunction etiology
mechanical: maternal position during labour, birthing position in 2nd stage of labour
iatrogenic: epidural analgesia
infection: chorioamnionitis
structural: uterine abnormality (e.g. fibroids, bicornuate uterus)
Uterine dysfunction management
1) active management
correctly diagnosis active phase of labour
early recognition of slowed progression, prompting timely use of augmentation
2) augmentation of labour
amniotomy if membrane has not ruptured and oxytocin IV
Oxytocin contraindication
a) 1. indication where C-section is more appropriate
significant cephalopelvic disproportion
2. unfavourable fetal position or presentation which are undeliverable without conversion prior to delivery
3. obstetrical emergency where benefit to risk ratio for fetus or mother favours surgical intervention
4. fetal distress where vaginal delivery is not imminent
b) hypertonic uterine contraction pattern
c) hypersensitivity to oxytocin
Shoulder dystocia definition
- difficult vaginal cephalic delivery of shoulder requiring additional obstetric maneuvers to deliver the fetus where gentle traction has failed
Shoulder dystocia pathophysiology
- shoulder dystocia can be due to impaction of anterior or posterior shoulder during vaginal delivery
- anterior shoulder impaction is much more common than posterior shoulder
- impaction
anterior shoulder impaction at maternal pubic symphysis; posterior shoulder impaction at sacral promontory
Shoulder Dystocia Risk Factors
- Pre-labour
- Macrosomia
- Previous history
- Induction of labour - Intra-partum risk factors
- Prolonged first and second stage
- Secondary arrest
- Oxytocin augmentation
- Assisted vaginal delivery
Diagnosis of shoulder dystocia
Clinically based on any of the following
- Difficulty with delivery of face and chin
- Head remaining tightly applied to vulva or even retracting (turtle neck sign)
- Failure of restitution of fetal head
- Failure of shoulder to descend
- Head to body delivery time exceeding 60 seconds
Shoulder dystocia risk factors
- Pre labour
- Macrosomia
- history of shoulder dystocia in previous deliveries with 12-25% recurrence risk
- induction of labour - Intra-partum risk factors
- Prolonged first and second stage
- Secondary arrest
- Oxytocin augmentation
- Assisted vaginal delivery
Shoulder dystocia diagnosis
Clinically based on any of the following:
- difficulty with delivery of face and chin
- Head remaining tightly applied to vulva or even retracting (turtle neck sign)
- Failure of restitution of fetal head
- Failure of shoulder to descend
- Head to body delivery time exceeding 60 seconds
Shoulder dystocia managment
- Prepare
- call for help including experienced ob, neonatal team, anesthesia
- discourage pushing, allow mother to lie flat and move buttocks to edge of bed - First line maneuvers
a) McRobert’s - sharp flexion of mother’s legs up onto abdomen with supra-pubic pressure (straightens sacrum relative to lumbar vertebrae, rotates pubic symphysis toward maternal head thereby decreasing angle of pelvic inclination to free anterior shoulder)
b) Episiotomy - consider incision if it will make internal maneuvers easier
c) Wood’s Maneuver - progressive rotating posterior shoulder 180 degrees in corkscrew fashion to release impacted anterior shoulder
d) Delivery of posterior shoulder - careful sweeping of posterior arm of fetus across chest followed by delivery of arm -> shoulder girdle rotated into oblique diameter of pelvis with subsequent delivery of anterior shoulder
e) Second Rubin Maneuver - rock shoulders side to side with force to the maternal abdomen - push most accessible fetal shoulder toward anterior surface of chest, resulting in abduction of both shoulders freeing impacted shoulder
f) All fours position - delivery baby with mother on all fours - Second line Maneuvers
- Cleidotomy - surgical division of clavicle or bending with finger
- Zavanelli maneuver - vaginal replacement of head then delivery by CS
- Symphysiotomy - dividing anterior fibers of maternal symphyseal ligament
Complications of shoulder dystocia
1) Maternal complications 3rd and 4th degree perineal tears post-partum hemorrhage infection uterine rupture fistula formation 2) Fetal complication brachial plexus injury: Erb brachial plexopathy or Duchenne brachial plexopathy Erb brachial plexopathy = extended and medially rotated arm, “waiter tip” most brachial plexus injury will resolve without permanent disability, <10% will have permanent neurological dysfunction clavicle or humeral fracture fetal distress -> death
Risk factors for postpartum hemorrhage
- failure to progress during 2nd stage of labour
- morbidly adherent placenta, abnormal placenta
- family history of PPH
- Asian or Hispanic race
- instrumental delivery
- large for gestational age newborn
- hypertensive disorder: pre-ecamplia, eclampsia, HELLP (hemolysis, elevated liver enzyme, low platelets)
- obesity
- multiple gestation
Differential diagnosis PPH
4 T’s: Tone, Tissue, Trauma, Thrombin early PPH (<24h): 4 T's late PPH (24h to 6 weeks): retained tissue, endometritis, sub-involution of uterus
Immediate management PPH
1) Stabilize patient
- 2 large bore IV’s, ensure ABC
- fluid resuscitation with IV crystalloids and blood transfusion if necessary (have 4 units pRBC ready)
- get help
2) Monitoring
- continuous monitoring
- blood work: CBC, INR, aPTT, cross & type
- Foley catheter to drain bladder and also measure urine output
- Inspection for lacerations
3) General medical therapy
- general medical therapy to facilitate uterine contraction and involution (uterotonics), which address uterine atony
- 1st line = Oxytocin 20 units / L NS or RL IV continuous infusion
- following utertonics can be added in addition to Oxytocin
a) Methylergonavine Maleate, an Ergotamine
b) Carboprost (Hemabate), a PGF-2 alpha analog
c) Misoprostil (Cytotec)
d) 15-Methyl Prostaglandin (Hemabate)
4) Source control
- retained placenta: use of uterotonics + controlled cord traction + uterine massage
- vaginal laceration: pressure and packing, surgical repair
- uterus bleeding: bimanual compression, intra-uterine balloon tamponade, uterine packing
- bleeding disorder
5) Invasive Intervention
- surgical option for uterus bleeding: B-lynch suture, Cho sutures, internal iliac ligation, hysterectomy
- internal radiology intervention for uterus bleeding: uterine artery embolization
PPH Definition
> 500 mL blood loss by vaginal delivery
> 1000 mL of blood loss by CS
Clinically any blood loss postpartum that results in hemodynamic instability
What is the most common cause of PPH
Tone: Uterine atony (75-80%)
Causes of uterine atony
- labour: prolonged, precipitous, induced, augmented labour, which all exhaust uterine muscle
- uterus: infection, over-distension (polyhydramios, multiple gestation, macrosomia, leiomyoma), functional or anatomic distortion, choioamnionitis
- placenta: abruption, previa
- maternal factors: grand multiparity (G>5), gestational hypertension
- anesthesia: halothane anesthesia
- other: bladder distension, MgSO4 treatment of pre-eclampsia
Methylergonavine Maleate contraindication
hypertension, HIV medication
Carboprost contraindication
Asthma, cardiovascular, pulmonary, renal and hepatic dysfunction
Hemobate contraindication
Severe asthma
Misoprostol relative contraindication
Careful in asthma
What is a B-lynch suture or Cho suture
compression suture to compress an atonic uterus, facilitating uterus involution
What is internal iliac ligation
ligation of internal iliac artery, which supply the uterus
Options for intrauterine balloon tamponade
Senstaken-Blakmore catheter, Foley catheter,
esophageal catheter, urologic balloon, hydrostatic condom catheter
What does bimanual compression entail in uterine bleeding
elevate uterus and massage through patient’s abdomen
Bleeding disorder management
- platelets for thrombocytopenia
- reversal of anti-coagulants
- fresh frozen plasma to reverse coagulopathy
Patient counseling regarding incision/wound management
C-section: dressing off in 3 days, staples removed in 3 days, sutures usually absorbable sutures, no heavy lifting >10 pounds in 2 weeks to prevent hernia
vaginal tear repair: sutures usually absorbable sutures, so no management post repair
Patient counseling regarding contraception options
- diaphragm and cervical cap should be delayed up to 6 weeks postpartum, because fitting cannot be performed properly until pregnancy-related cervical changes have regressed
Breast-Feeding Mothers
- condoms, progestin only contraceptives or IUD immediately post delivery
- OCP may be started >4 weeks postpartum for women without additional risk factors for VTE or >6 weeks for women with additional VTE risk factors
Non-Breast-Feeding Mothers
- condoms, progestin only contraceptives or IUD may be started immediately after delivery
- OCP NOT recommended for first 6 weeks after delivery with risk factors for VTE
Post partum mood disorders
- Baby blues (aka postpartum reactivity) = common mood swings or mild feelings of sadness after childbirth
- Postpartum depression
- Postpartum psychosis
- Postpartum anxiety including panic disorder, social phobia, generalized anxiety
- Postpartum obsessive compulsive disorder
Patient counseling regarding nutrition and post partum weight loss
- additional 500kcal per day is recommended for breastfeeding women
- calcium intake >1000mg/day
- iron intake >15mg/day
- naturally, with healthy diet and exercise, much of the weight gained during pregnancy will be shed naturally during 1st year postpartum
- postpartum weight loss should be gradual <4.5lbs/month
Effects of smoking and second hand smoke on baby
Second hand smoking increases risk to baby’s health including
- sudden infant death syndrome
- lung diseases: asthma, pneumonia
- allergies
- ear infections
- learning disorder, ADHD
Smoking result in decreased milk production and nicotine in breast milk, which cause agitation, restlessness and tachycardia in baby
Patient counseling regarding consumption of alcohol and recreational drugs
- occasional consumption of small amount of alcohol are not contraindicated during breastfeeding (try to breastfeed before drinking when possible)
- breast feeding is discouraged if mother is actively using illicit drugs or used illicit drug within 30 days prior to delivery (especially IV drug use)
Patient counseling regarding neonatal care
- well baby visits at 1 week, 1 month, 2 months, 4 months, 6 months, 12 months, 2-3 years, 4-5 years
Why are progestin only contraceptive agents preferred over OCP in breast feeding mothers postpartum
progestin does not affect milk volume or composition
In breast feeding women, anovulation is likely only when all of the following conditions are met:
1) <6 months postpartum
2) breast feeding exclusively
3) amenorrhea
When does ovulation recur in non breast feeding mothers
Ovulation can occur as early as 25 days (usually 45 to 90 days) postpartum
Pathophysiology of delayed ovulation in breast feeding mothers
women who breastfeed have delay in resumption of ovulation postpartum due to prolactin-induced inhibition of GnRH form hypothalamus
Importance of early contraception post partum
Decreased birth interval can have negative health affects for mom and baby including preterm birth and low birth weight
Post partum mood disorders clinical presentation
- Blues usually peak approximately 3-5 days postpartum and disappear within a couple of weeks
- Postpartum depression: onset usually within first 3 months postpartum with low mood, sadness, hopelessness, low self esteem, guilt, feeling of being overwhelmed, inability to be
comforted, feeling of emptiness, anhedonia, social withdrawal, sleep disturbance, suicidality, poor functioning - Postpartum psychosis: hallucination, delusions, agitation
- Postpartum anxiety: excessive worry, feeling anxious, short temper, irritability, common in first week
Post partum depression prevention
- Lifestyle modification with rest, diet, exercise, support, delay going back to work for at least 6 weeks postpartum
- if any symptoms of depression, seek healthcare
Post partum depression treatment
biological: SSRI
psychological: CBT, IPT
social interventions
Effect of marijuana on mother and baby
- marijuana can be transferred to infant via breast milk and passive smoking
- effect on mother: decreased milk production
- effect on infant: sedation, weakness, poor feeding pattern
Effect of opioid on baby
- heroin is not transferred to baby, but methadone is transferred via breastmilk to baby
- effect on infant: opioid withdrawal symptoms if ceased (tremor, restlessness, vomiting), sedation, poor feeding
Hallucinogen/amphetamines effect on baby
- no published information on ecstasy excretion into breast milk
- effect on infant: drug induced behavioural abnormality including irritability, poor sleeping pattern, agitation, crying
Benzodiazepines effect on baby
- no effect on infant documented
Cocaine effect on baby
- cocaine is excreted into breast milk in high concentration
- effect in infant: irritability, vomiting, diarrhea, tremor, seizure, dilated pupil
Alcohol affect on mom and baby
- alcohol can interfere with milk letdown reflex and reduce milk production
- large amount of alcohol during breastfeeding can cause adverse effects including
a) decreased milk intake
b) impaired motor development
c) altered sleep pattern
IUFD definition
after 20 weeks gestation
IUFD risk factors
Risk Factors
1) Maternal factors
- advanced maternal age
- OB&GYN history: prior stillbirth, post-term pregnancy
- comorbidity: obesity, maternal comorbidity
- social history: smoking, illicit drugs and alcohol
2) Current pregnancy factors
- fetal growth restriction
- fetal macrosomia >90th percentile
- multiple gestation
- no antenatal care
IUFD clinical presentation
Symptoms
-decreased perception of fetal movement by mother
-uterine contraction
-vaginal bleeding
Signs
-symphysis fundal height and maternal weight not increasing
-absent fetal heart tones on auscultation
IUFD etiology
50% cases are idiopathic
fetus (25-40% cases): chromosomal anomalies, non-chromosomal birth defect, congenital anomalies, erythroblastosis fetalis (Rh related hemolytic anemia), non-immune hydrops,
intra-uterine infection, fetal vascular thrombosis
placenta (25-35% cases): premature ruptured membrane, placental abruption, feto-maternal hemorrhage, cord accident, cord prolpase, placental insufficiency, intra-partum asphyxia,
placental previa, twin-twin transfusion syndrome, chorioamnionitis, utero-placental under-perfusion
maternal (5-10% cases): diabetes, hypertensive disorders, obesity, thyroid disease, renal disease, anti-phospholipid anti-bodies, thrombophilias, infection & sepsis, pre-term labour,
abnormal labour, uterine rupture, post-term pregnancy, smoking, illicit drugs, alcohol
IUFD complications
- disseminated intravascular coagulopathy (DIC)
- infection
IUFD Investigations
blood work: high maternal serum AFP
ultrasound: absent cardiac activity, absent fetal movement
fetal autopsy is most useful for determining cause for intra-uterine fetal demise
IUFD diagnosis
intra-uterine fetal death diagnosed based on absent cardiac activity and absent fetal movement on ultrasound
IUFD management
deliver fetus by any of the following:
- spontaneous labour and vaginal delivery: spontaneous labour usually beings within 1-2 weeks of fetal death
- induced labour (cervical ripening with mechanical method, then Oxytocin in 3rd trimester or Misoprostol in late 2nd trimester) and vaginal delivery, which is the
standard of care and safer than C-section
- dilatation and evacuation for smaller pregnancies, usually less than 18-24 weeks
- C-section only in special circumstances
monitor for maternal coagulopathy, especially if intra-uterine demise lasting >4 weeks without spontaneous delivery
if given consent, conduct investigations for secondary causes
Psychological Care
- hold newborn (developing physical or visual connection with baby makes death real and help prevent emotional withdrawal form
loss)
- make neonatal footprint, take photo of newborn, encourage to name child
- early discharge home
- early follow up within 2 weeks to assess mental wellbeing
- comprehensive discussion within 3 months about final investigation and post-mortem results, which may help make plans for future pregnancy
- pregnancy after stillbirth should be delayed until parents feel psychological closure of previous pregnancy loss (usually takes 6-12 months)
DIC in IUFD pathophysiology
- uncontrolled release of plasmin and thrombin (from placenta into maternal circulation in case of intra-uterine fetal death) leading to intravascular coagulation, which consumes and
depletes platelets, coagulation factors and fibrinogen - consumption of platelets, coagulation factors and fibrinogen increases risk of life threatening hemorrhage
DIC in IUFD clinical presentation
DIC result in thrombosis and hemorrhage
1) signs of microvascular thrombosis
neurological: multifocal infarcts, delirium, coma, seizure
pulmonary: acute respiratory distress syndrome
renal: renal failure causing oliguria, azotemia
GI: acute GI ulcer
skin: focal ischemia, superficial gangrene
RBC: microangiopathic hemolysis
2) signs of hemorrhagic diathesis
bleeding form any site in body due to thrombocytopenia or deficiency in clotting factors
neurologic: intracranial bleeding
skin: petechiae, ecchymosis, oozing from puncture sites
renal: hematuria
mucosal: gingival oozing, epistaxis, massive bleeding from mucosal sites
DIC in IUFD investigation
blood work: CBC, blood film, INR, aPTT, FDP (fibrinogen degradation products), Fibrinogen
CBC: thrombocytopenia from consumption of platelets
blood film: schistocytes from microangiopathic hemolysis
INR, aPTT: prolonged from consumption of coagulation factors
FDP: increased FDP from fibrinolysis
fibrinogen: decreased form fibrinolysis
DIC in IUFD treatment
- treat underlying cause such as delivery of fetus
- hemorrhage: replacement of hemostasis with platelets for thrombocytopenia, fresh frozen plasma or cryoprecipitate for prolonged aPTT / INR
- thrombosis: low molecular weight heparin may be considered (controversial)
- supportive management: IV fluids
Termination of pregnancy definition
active termination of pregnancy before fetal viability (<500g or less than 20 weeks gestational age)
Termination of pregnancy indication
maternal health: pregnancy puts mother at risk such that pregnancy cannot be continued (e.g. severe cardiac disease)
failed pregnancy: fetal demise, incomplete abortion
social: patient personal preference
Termination of pregnancy management
abortion can be done by medical or surgical means
A) Medical Management
- medical management results in fetal demise, which is then delivered vaginally
- medical management requires facility for surgical management in case medical management fails
- fetus <9 weeks: Methotrexate (PO or IM) plus Misoprostol (PO or vaginally)
- fetus >12 weeks: Prostaglandin (IM or intra-amniotically or extra-amniotically) or Misoprostol (PO or vaginally)
B) Surgical Management
- fetus less than 12-14 weeks: dilatation and curettage aka vacuum aspiration (curette to scrap lining of uterus and remove tissue)
- fetus older than 12-14 weeks: dilatation and evacuation (vacuum to remove tissue form uterus)
Termination of pregnancy surgical management complications
pain & discomfort, hemorrhage, uterus perforation, cervix laceration, risk of future infertility, infection / endometritis, Asherman’s syndrome (adhesion within
endometrial cavity causing amenorrhea / infertility), retained products of conception
