Obstetrics Flashcards
1
Q
Pre-eclampsia background
A
Epidemiology
- approximately 5% of pregnancies
- in approx 0.5% of cases
- > eclampsia
- > maternal death
Aetiology
- unknown
- risk factors
- > previous hx
- > family hx
- > primip
- > multiple pregnancy
- > older age
- > obesity
- > HTN
- > diabetes
- > renal disease
- > autoimmune disease
Pathophys
- normal pregnancy
- > invasion of trophoblastic cells into spiral arteries
- > remodelling into large capacitance vessels
- pre-eclampsia
- > trophoblastic cells invade endo but not myometrium
- > normal spiral artery remodelling does not occur
- > placental hypoperfusion, hypoxia, ischaemia
- > release of antiangiogenic factors into maternal circulation
- > alters systemic endothelial function
- > vasoconstriction and increased permeability
2
Q
Pre-eclampsia evaluation
A
Hx
- Timing
- > most commonly after 34 weeks
- > almost always after 20 weeks
- > occasionally during labour or postpartum
- May be asymptomatic
- Severe symptoms screen
- > altered mental status
- > severe, persistent headache
- > severe, persistant RUQ/epigastric pain
- > photopsia/scotoma/blurred vision
- > new dyspnoea/orthopnoea
- Fetal wellbeing
- > fetal movements
- > abruption (abdo pain/contractions/PV bleeding)
- Obstetric hx
- > previous pregnancies/complications/HTN
- > GA/route of delivery
- Medical hx
- > chronic illnesses?
- > HTN/CVD
- > kidney disease
- > diabetes
- Allergies
- Medications
- Social
- > smoking/drinking/drugs
Exam
- Height/weight/BMI
- HTN
- > 2 readings 4 hours apart
- Hyper-reflexia or clonus
- > indicates severe disease
- Oedema
- > pulmonary
- > peripheral
- Fundoscopy
- > rarely abnormal (would imply underlying HTN)
- > arteriolar narrowing/cotton wool/flame haemorrhages
- Abdo palpation
- > assess lie/presentation for pre-term delivery
- Fundal height
- > reduced = raised concern for IUGR (30% incidence)
- Doppler
- > FHR
Investigations
- urinalysis
- > protein 2+ on dipstick
- > UACR >30
- FBC
- > anaemia?
- > thrombocytopaenia?
- EUC
- > raised creatinine?
- LFTs
- > raised transaminases?
- Consider
- > coags if thrombocytopaenic
- > CXR if concern for pulmonary oedema
Fetal wellbeing
- Initial assessment
- > growth scan
- > BPP (NST/tone/movement/breathing/AFI)
- > umbilical artery doppler (reduced end diastolic flow)
- Ongoing monitoring
- > umbilical dopplers most useful
- > growth scans can be repeated in 2 weeks for velocity
Pre-eclampsia criteria
- HTN plus
- > proteinuria or
- > end organ dysfunction
- > growth restriction
Severe pre-eclampsia criteria
- SBP >160 or DBP>110
- CNS symptoms
- > visual disturbance
- > severe headache
- Liver involvement
- > transaminase >2x upper limit
- > severe RUQ pain
- Renal involvement
- > creatinine >2x upper limit
- Thrombocytopaenia
- > less than 100,000/microL
- Pulmonary oedema
- HELLP syndrome
- > severe subtype of pre-eclampsia
- > haemolytic anaemia
- > elevated Liver enzymes
- > low Platelets
3
Q
Severe pre-eclampsia management
A
Prelabour
- Strictly inpatient management
- > labour/delivery unit (consider tertiary transfer if ex pre)
- > regular (4x daily) BP monitoring
- > accurate fluid monitoring
- > repeat blood tests daily (on advice)
- > fetal wellbeing (dopplers and CTG)
- Indication for delivery
- > certainly for >34wks
- > probably for >24wks (consider tertiary transfer)
- Route
- > no clear evidence for absolute caesarian need
- > consider parity/GA/severity etc
- Magnesium sulfate IV
- > approx 4g IV then 1g/hr infusion (diluted)
- > given immediately prophylactically
- Anti hypertensives
- > labetalol IV (start at 20mg and work up)
- > hydralazine IV
- > caution nifidepine
- Anaesthetic review
- > neuraxial = haematoma (platelets)/hypotension
- > general = hypotension/hypertensive extubation/laryngeal oedema
- > morphine = cardiorespiratory depression
- Corticosteroids
- > delay delivery by 48hrs if possible for full course
- > betamethasone favoured
- > clear benefit for <34 wks/ likely benefit <37 wks
- Thrombocytopaenia
- > transfusion usually only given if severe or bleeding
Intrapartum
- Monitoring
- > maternal HR/BP/RR/O2
- > accurate fluid balance/consider maintenance fluids
- Maintain antihypertensive therapy
- Fetal wellbeing
- > neonatologist/paediatrician attending
- > continuous FHR
- > glucose and cord gases
Postpartum
- Magnesium sulftate
- > no clear evidence for safe duration
- > usually up to 48 hrs
- > regular monitoring for SE
- Bloods
- > daily monitoring until repeatedly normal
- Blood pressure
- > often peaks in first week postpartum
- > may last several weeks
- > continue treating/swap to oral when non severe
- Fluids
- > risk of overload and pulmonary oedema
- > restrict until passing urine freely
4
Q
aneuploidy screening
A
Discuss
- patient hx
- > concerns
- > family hx
- > risk factors
- genetic conditions
- > information on common genetic conditions
- > risks for pregnancy, baby and beyond
- > concept of phenotypic variability
- genetic testing
- > description of available tests
- > benefits and limitations of different tests
- > screening vs diagnosis
- > risk of unexpected findings without solutions
- > private costs
- implications
- > continue or terminate pregnancy
- > palliate baby with terminal illness
- > timing and restriction of abortion methods
- supports and further information
- > referral to genetic counselling
- > written information
- > support groups
Combined first trimester screening
- Timing
- > 11-13+6 weeks
- Components
- > NT = >95th centile
- > PAPP-A = low
- > b HCG = high
- > maternal age
- > gestational age
- Cost = approx $100
- Conditions tested (66% of all aneuploidies)
- > trisomy 21 (Down)
- > trisomy 13 (Patau)
- > trisomy 18 (Edwards)
- Performance for 21
- > sensitivity = 85%
- > FPR = 5%
- Soft markers increase sensitivity/specificity
- > nasal bone/DV waveform/tricuspid flow
- Confounders
- > maternal weight
- > smoking
- > IVF
- Report of results
- > risk of disease
Cell free DNA
- Timing
- > from 10 weeks
- > consider as secondary screen
- Components
- > maternal serum taken
- > fetal fraction and number of sequence specific chromosomes = presence of aneuploidy
- Offer early anatomy US @ 11-13 weeks
- Conditions screened
- > autosomal trisomies (21/13/18)
- > sex chromosome aneuploidies
- > micro deletions (diGeorge) not recommended
- Unable to provide a result in approx 5%
- > early GA
- > suboptimal collection
- > low FF in obese mothers/fetal karyotype/IVF
- Private cost approx $400
- Trisomy 21 performance
- > sensitivity = 99%
- > PPV = 90%
- Causes of inaccuracies
- > placental mosaicism
- > maternal mosaicism
- > vanishing twin
- > copy number variants
- > maternal cancer
- Report of results
- > positive/negative
- > high risk/low risk
Second trimester testing
- maternal serum screening (PPV = 3%)
- > at 15-20 weeks
- > maternal age
- > AFP
- > b HCG
- > UE3
- > Inhibin
- cfDNA (from 10 weeks)
5
Q
aneuploidy diagnostic tests
A
Indications
- > patient preference (before screening)
- > postive genetic screen
Relative contraindication
- > alloimmunisation
- > HIV
- > Hep B/C
Amniocentesis
- timing
- > from 15 weeks gestation
- > before = high risk adverse outcomes
- procedure
- > withdraw amniotic fluid using needle
- > ultrasound guidance
- post procedure care
- > uterine cramping normal
- > spotting/amniotic fluid leak immediately after
- risks
- > rupture of membranes
- > indirect fetal injury (talipes/respiratory)
- > direct fetal injury (rare)
- > fetal loss = 0.5% (1/200)
- > infection (rare)
Chorionic villus sampling
- timing
- > from 11 weeks
- > before = high risk complications
- procedure
- > tertiary institute
- > ultrasound guided
- > transabdominal/transcervical approach
- > placental tissue aspirated into syringe
- > mild pain
- post procedure care
- > no exercise or sex 24hrs
- > some light spotting is normal
- risks
- > fetal loss approx 1% (1/100)
- > transverse limb reduction defects
- > sampling failure
- > vaginal bleeding
- > infection (rare)
Assessment of sample
- extremely low false negative rate
- > variants of unknown significance in 5%
- methods
- conventional karyotyping
- FISH
- chromosomal microarray
6
Q
diabetes pregnancy background and complications
A
Epidemiology
- GD = approx 10% pregnancies
- pre-existing = 2% pregnancies
Aetiology
- pre-existing
- GD risk factors
- > older age
- > personal hx
- > family hx
- > obesity
- > physical inactivity
- > high GI/low fibre diet
- > smoking
- > PCOS
Pathophys GD
- relative insulin resistance normal part of pregnancy
- > ensures adequate glucose delivery to fetus
- > most marked resistance in 3rd trimester
- diabetogenic hormones released by placenta
- > growth hormone
- > prolactin
- > lactogen
- > progesterone
- GD develops when maternal beta cells are overwhelmed
Shared complications
- short term
- > LGA = preterm/caesarian/instrumental/dystocia/injury
- > polyhydramnios = BPD/preterm/malposition
- > pre-eclampsia
- > neonate = hypoglycaemia/jaundice/CMP/cardiac/resp
- long term
- > increased risk of T2DM
- > child = obesity/metabolic syndrome/diabetes
Pre-existing complications
- Congenital defects
- > 2-4%x base (incidence apex 5%)
- > CCHD/neural tube defects
- IUGR
- Pre-eclampsia/HTN
- Miscarriage
- Aggravates underlying micro/macrovascular disease
- DKA more common
- > occurs at higher BGL
- > more lethal for mother (fetal demise also common)
7
Q
diabetes pregnancy evaluations and non BGL management
A
Screening
- first antenatal visit
- > all women
- > low risk GD = BGL/high risk GD = GTT
- > pre-existing = HbA1c/UACR/GFR/TSH/fundoscopy
- 24-28wks
- > all women GTT
Diagnosis
- GTT
- > NBM for 8hrs prior
- > fasting glucose
- > 75g glucose
- > glucose at 1 hr
- > glucose at 2hrs
- GDM criteria
- > fasting = >5.1
- > 1hr = >10.0
- > 2hr = >8.5
- pre-existing diabetes
- > if diagnostic criteria met <1st trimester
1st trimester
- Pre-existing
- > cease ACEI/ARB
- > low dose aspirin after 12wks
- > higher folic acid supplementation
2nd trimester
-morph/neural tube scan at 20wks
3rd trimester
- GD and good control/lifestyle only
- > fetal movements may be sufficient
- > growth scans close to term
- Poor control/pre-existing
- > NST/ST/BPP from 32 wks
- > serial growth scans from 32 wks
- > increase insulin if steroids given
Labour
- Timing
- > consider induction after 39/before 40wks
- Route
- > consider delivery at term for macrosomia
- > consider caesarian for macrosomia >4.5kg
- Intrapartum
- > maternal glucose monitoring (fetal hypoglycaemia)
- > continuous FHR
- Post partum
- > neonatal glucose monitoring
- > loss of insulin resistance with placental delivery
- > monitor glucose for 24-72hrs (unrecognised T2DM)
8
Q
diabetes pregnancy BGL management
A
Diet
- referral to dietician
- > caloric needs individualised
- > determined by baseline and GA
- best evidence for low GI diet (vs low carb/calorie restricted)
- > less insulin requirements
- > lower birth weights
- some evidence for increasing folic acid supplementation
Exercise
- moderate intensity exercise
- > increased muscle mass = increased insulin sensitivity
- > lower blood glucose levels
- > less insulin requirements
Insulin therapy
- after lifestyle trial for 2-4wks
- trial intermediate acting basal insulin at bedtime
- > approx 6 units
- assess fasting BGL over week
- > more than 3 > 5 = increase by 2 units
- > more than 3 > 6 = increase by 4 units
- > more than 3 > 8 = increase by 6 units
- avoid prolonged fasting at night
- > paradoxically raises morning fasting levels
- consider adding pre-prandial rapid acting bolus
- > split approx 50% of total daily dose across meals
Glucose self monitoring
- 4x daily
- > fasting/waking
- > post prandial (1-2hrs)
- log in book
Glucose targets
- fasting <5.3
- 1hr post prandial <7.8
- 2hr post prandial <6.7
9
Q
ectopic pregnancy background
A
Epidemiology
- approx 1% of all pregnancies
- up to 15% of first trimester bleeding
Aetiology
- risk factors (ASEPTIC)
- > age (older)
- > smoking
- > ectopic pregnancy in previous pregnancy
- > PID
- > tubal abnormalities
- > infertility and IVF
- > contraception failure (IUD/COP)
Pathophys
- anatomic sites
- > fallopian tubes (more than 95%)
- > ovarian
- > interstitial
- > abdominal
- > cervical
- > hysterectomy scar
- > intramural
- > heterotopic
10
Q
Ectopic pregnancy evaluation
A
Hx
- Onset of symptoms usually after 8 weeks gestation
- Vaginal bleeding
- Lower abdo pain
- > sharp or dull (not crampy)
- > diffuse or localised
- Rupture
- > acute severe pain
- > severe bleeding
- > syncope
- > shoulder tip pain
- > tenesmus = blood in pouch of douglas
- Pregnancy risk
- > LMP
- > hx unprotected sex/known pregnancy
- > pregnancy symptoms (fatigue/mastalgia/nausea)
- Obstetric hx
- > previous pregnancies
- > previous ectopics/miscarriages
- Menstrual hx
- > regularity
- > intermenstrual/menorrhagia
- Gynae
- > contraception
- > STI/PID
- Social
- > smoking
Review medical fitness
- > lung/liver/kidney/peptic ulcer disease
- > allergies (methotrexate)
- > medications (immunosuppression/folate supplement)
Review surgical fitness
->previous operations (sites/complications/bleeding)
Exam
- Often unremarkable
- Vitals
- > assess for shock (cap refill/warmth/colour/JVP)
- > BP/postural hypotension
- Abdo
- > tenderness?
- > acute abdomen in rupture
- Speculum
- > source of bleeding
- Pelvic
- > adnexal mass/tenderness
- > cervical motion tenderness with rupture
Investigations
- Unstable
- > FAST scan for intraperitoneal haemorrhage
- Quantitative b HCG
- > confirms pregnancy
- > provides level
- Blood group and antibodies
- > hold if significant bleeding
- > sensitising event (anti D)
- FBC
- > anaemia due to haemorrhage
- > baseline for methotrexate
- EUCs and LFTs
- > methotrexate baseline
- Transvaginal ultrasound
Transvaginal ultrasound
- Confirms ectopic
- > gestational sac with yolk sac/embryo at ectopic site
- > adnexal mass/empty uterus/free fluid
- Suggests ectopic
- > pseudosac
- > complex extra ovarian adnexal mass
- > tubal donut sign
- > adnexa ring of fire sign on doppler
- > consider heterotopic
- Suggests rupture
- > fluid in morrisons or douglas’ pouch
- Absence of findings
- > follow PUL protocol
11
Q
medical management ectopic
A
Indications
- > patient preference
- > stable
- > b HCG <5000
- > no cardiac tones / ectopic mass <3-4cm
Contraindications
- > unstable
- > evidence of threatened rupture
- > viable IUP/heterotopic
- > liver/renal/pulmonary disease
- > immunosuppression or peptic ulcers
- > abnormal FBC, EUCs, LFTs
- > breastfeeding
Risks
- approx 1/3 experience side effects
- > nausea/vomiting
- > stomatitis/rash/itch/urticaria
- > photosensitivity
- rarely
- > transaminitis/nephrotoxicity/myelosuppression
- treatment failure approx 20%
Benefits
- > avoids surgical complications
- > similar efficacy to surgery when adequate doses given
- > similar fertility outcomes to surgery
- > similar risk as surgery of further ectopic pregnancies
Procedure
-IM single dose
Monitoring
- b HCG on days 4 and 7
- b HCG weekly until 0
- inadequate decrease
- > repeat dose (no more than three total)
Advice
- > avoid conception for 4 months
- > avoid folic acid supplements and NSAIDs
- > avoid sunlight
- > mild pain at 1 week is common
- > severe pain needs to be investigated
12
Q
surgical management ectopic
A
Indications
- any b HCG level
- unstable
- rupture or impending rupture
- heterotopic ectopic
- methotrexate contraindications
- methotrexate failure
Contraindications
-no absolute
Risks
- surgical and anaesthetic risks
- > haemorrhage
- > infection
- > damage to bowel or bladder
- > adhesions/hernias
- > nausea/vomiting post op
- fertility
- > vast majority will achieve conception if they try
- retained ectopic tissue
- > need for methotrexate therapy
Procedure
- salpingectomy vs salpingostomy
- > similar rate of future fertility
- > salpingostomy = higher rate of retained/future ectopics
- laparoscopic vs laparotomy
- > laparoscopic preferred
- > laparoscopic = less blood loss, faster operation, recovery and discharge
- > consider laparotomy for interstitial or unstable
Follow up
- > regular GP to follow up with?
- Salpingostomy
- > weekly b HCG until negative
- > insufficient b HCG decrease = methotrexate
- Salpingectomy
- > post op B HCG unnecessary if histopath confirmed
- Future conception
- > no solid data
- > 0-3 months common
13
Q
expectant management ectopic
A
Indications
- asymptomatic
- no TVU findings of ectopic pregnancy
- low (<1500) and decreasing b HCG
- aware of risks
- access to emergency treatment and close follow up
Contraindications
-any of indications absent
Risks
-rupture can occur with low and falling b HCG
Benefits
- similar success rate (80%) to medical management
- similar treatment time as medical management
Procedure
- b HCG every 48hrs for 7 days
- > then weekly until negative
- abandon expectant management if
- > any symptoms
- > b HCG not decreasing
- avoid conception until sonographic resolution
14
Q
Miscarriage (<20 wks) background
A
Epidemiology
- early pregnancy loss (first trimester)
- > 10% clinically recognisable pregnancies
- early second trimester loss (<20 weeks)
- > less than 1% of pregnancies
- almost half of parous women have EPL
Risk factors (ADIPOSE)
- Age
- > maternal
- > possible paternal
- Diabetes
- > euglycaemia risk is baseline
- Infection
- > CMV
- > syphilis
- > parvovirus B19
- Previous miscarriage
- > OR for 1 = 1.5
- > OR for 2 = 2.2
- Obesity
- Substances
- > medications
- > alcohol, smoking, cocaine
- Exposures
- > lead/arsenic
- > air pollution
- > radiation
Aetiologies
- chromosomal abnormalities
- > approx 3/4 of miscarriages
- uterine abnormalities
- > ashermans syndrome
- > fibroids
- > polyps
- direct trauma
- > violent
- > iatrogenic (chorionic villus sampling)
15
Q
miscarriage evaluation
A
Hx
- confirm pregnancy
- > LMP
- > pregnancy test results
- bleeding
- > clots
- > tissue
- pain
- > cramping
- > shoulder tip
- loss of pregnancy symptoms
- syncope
- > hypovolaemia
- infection
- > fever
- > purulent discharge
- obstetric hx
- > previous pregnancies
- > previous miscarriages
- > assisted conception
- gynaecological hx
- > surgeries
- > significant conditions
- previous investigations
- > US
- > b HCG
Exam
- vitals
- > fever/tachycardia/hypotension = infection
- > tachycardia/hypotension = hypovolaemia
- > bradycardia/hypotension = tissue in cervical canal
- abdo
- > tenderness/guarding
- > distension
- > enlarged uterus
- speculum
- > bleeding from cervix
- > open os
- > tissue in cervical canal
- bimanual
- > cervical motion tenderness
- > uterine tenderness in infection
- > adnexal mass
Investigations
- b HCG
- > urine
- > serum
- FBC
- blood group and antibodies
- > transfusion
- > sensitising event
- Coags
- Consider
- > MSU
- > STD
- Initial transvaginal ultrasound
- > IUP
- > ectopic pregnancy
- > absence of findings (PUL/complete miscarriage)
- > GTD
