Obstetrics Flashcards
What is most distressing immediate complication of perineal injury?
Perineal pain
SOGC 330
What are the reported rates of anal incontinencefollowing primary repair of OASIS range?
Between 15-61%. Mean 39%
SOGC 330
Which degree of OASIS does the patient have if her external sphincter is more than 50% torn?
3b
SOGC 330
Which of the following will have the highest risk of anal sphincter injury?
- Occiput posterior and vacuum delivery
- Forceps and mediolateral episiotomy
- Large gestational age and vacuum delivery
- Midline episiotomy and forceps
- Midline episiotomy and forceps
SOGC 330
By how much (%) does head control at the time of delivery decrease the risk of anal sphincter injury?
50-70%
SOGC 330
What is the NNT of a Cesarean section to prevent one patient with a previous OASIS?
2.3
To prevent 1 case of anal incontinence in a women with a previous OASIS, 2.3 elective CS need to be done.
SOGC 330
Is it the internal or external anal sphincter that is most responsible for maintaining anal sphincter tone at rest?
Internal anal sphincter
○ 70-80% of resting anal pressure
○ 40% of anal pressure in response to sudden distention
○ 65% of anal pressure in response to constant rectal distention
SOGC 330
Does pregnancy increase or decrease or not affect the levels of the following factors?
- Factor VIII
- von Willebrand Factor
- Factor IX
- Factor XI
- Increase, reaches its maximal peak at 29-35 weeks
- Increase, reaches its maximal peak at 29-35 weeks
- Unchanged
- Unchanged
Returns to normal about 7-10 days after delivery
SOGC 163
What is average yearly number of births to adolescent mothers worldwide?
14 million
10% of births worldwide
23% of maternal morbidity and mortality
SOGC 327
Name 9 risk factors for the development of GDM and Type 2 diabetes postpartum.
- Maternal age >35
- Obesity BMI >30
- Ethnicity (Aboriginal, African, Asian, Hispanic, south Asian)
- Family hx of diabetes
- PCOS
- Acanthosis nigricans
- Corticosteroid use
- Previous pregnancy complicated by GDM
- Previous macrosomic infant
SOGC 393
According to the SOGC, at how many weeks should screening for GDM be offered?
24 to 28 weeks
SOGC 393
What are the abnormal values of the OGTT at fasting for the 2-step approach? 1-hour? and 2-hour?
Fasting >=5.3
1-hour >=10.6
2-hour>=9.0
For alternative 1-step approach, values are a bit different:
Fasting >= 5.1
1-hour >= 10.0
2-hour >=8.5
SOGC 393
What are the targets for maternal glycemic control?
Fasting <5.3
1-hour 7.8 OR 2-hour 6.7
SOGC 393
In pregnant women who have not yet received screening or diagnostic testing for GDM, how many days after a betamethasone injection can we perform the test?
After 7 days
** Note that recommended to do a 1-step 75g OGTT
SOGC 393
Name the contraindications to VBAC. (5)
- Previous classical incision
- Previous inverted T incision or low vertical incision
- Previous full-thickness surgery (e.g. myomectomy)
- Previous uterine rupture
- Patient refusal to TOLAC
SOGC 382
What are some factors that increase the likelihood of VBAC?
Maternal ○ Age <=30 years old ○ BMI <30 ○ Caucasian Obstetric ○ Previous vaginal birth *** Best odds ratio ○ Previous CS indication not dystocia ○ Spontaneous labor ○ Bishop Score >=6 on admission Fetal ○ Birth weight <4000g
SOGC 382
What is the most important predictor for a successful VBAC?
Previous vaginal delivery
86.7% instead of 60.9% if they never delivered vaginally
* 63.3% after 0 VBAC * 87.6% after 1 VBACs * 90.9% after 2 VBACs * 90.6% after 3 VBACs * 91.6% after 4 or more VBACs
SOGC 382
What is the most common finding in women who experience a uterine rupture?
Fetal tracing abnormality
SOGC 382
What is the percentage of uterine rupture in a patient who has had
A) 1 previous LTCS?
B) a classical CS?
C) an inter delivery interval of less than 12 months?
A) 0.4%
B) 4-9%
C) 4.8%
SOGC 382
What is the percent of uterine rupture in a woman who has had 1 previous CS and undergoes
A) induction of labour with oxytocin for a favourable cervix?
B) IOL with PGE2?
C) IOL with misoprostol?
A) 1.1%
B) 2%
C) 6%
SOGC 382
What is the incidence of vasa previa in patients with villamentous cord insertions?
1 in 50
SOGC 231
Name 4 risk factors for vasa previa.
Risk factors for vasa previa
• IVF (1 in 202 instead of 1 in 2200 for non-IVF)
• Second trimester placenta previa
• Bilobed and succenturiate-lobed placentas
• Fetal anomalies (renal tract anomalies, spina bifida, single umbilical artery, exomphalos)
Must be a villamentous cord insertion!
One of these risk factors is present in 89% of vasa previa cases
SOGC 231
What is the recommended delivery management for a pregnancy known for placenta previa?
Planned elective CS at 35-36 weeks
Betamethasone at 28-32 weeks of gestation
Antenatal admission is debated
SOGC 231
What is the recommendation for exercise in pregnancy?
150 minutes of moderate intensity exercise per week if the patient has no contraindications
SOGC 367
What are the contraindications to exercise in pregnancy?
Absolute contraindications to exercise:
• Ruptured membranes
• Premature labour
• Unexplained persistent vaginal bleeding
• Placenta previa after 28 weeks gestation
• Pre-eclampsia
• Incompetent cervix
• Intrauterine growth restriction
• High-order multiple pregnancy (triplets)
• Uncontrolled type 1 diabetes
• Uncontrolled hypertension
• Uncontrolled thyroid disease
• Other serious cardiovascular, respiratory or systemic disorder
Relative contraindications to exercise • Recurrent pregnancy loss • Gestational hypertension • Hx of spontaneous preterm birth • Mild/mod cardiovascular or respiratory disease • Symptomatic anemia • Malnutrition • Eating disorder • Twin pregnancy after 28th week • Other significant medical conditions
SOGC 367
True or false.
Prenatal physical activity is associated with a reduction in odds of GDM, pre-eclampsia, gHTN, prenatal depression and macrosomia WITHOUT increasing odds of adverse outcomes including preterm birth, low birth weight, miscarriage and perinatal mortality
True
SOGC 367
Should pelvic floor muscle therapy be recommended in pregnancy to decrease risks of urinary incontinence?
Yes it should.
Prenatal PFMT is associated with 50% reduction in prenatal and 35% reduction in postnatal urinary incontinence
SOGC 367
What is the definition of a surgical site infection and what percentage occurs after hospital discharge?
SSI is infection of the incision up to 30 days after the surgery.
84% of SSI occurs after discharge from the hospital
SOGC 247
In what 2 situations should another dose of prophylactic antibiotic be administered?
- Surgery duration > 3 hours
- Estimated blood loss > 1.5L
SOGC 247
What is the most important risk factor for postpartum maternal infection?
Cesarean section
SOGC 247
What is the recommended antibiotic regiment for 3rd or 4th degree perineal tears?
Cefoxitin 1g IV x1 or Cefotetan 1g IV x1
SOGC 247
Penicillin allergy is reported in what percentage of patients? How many of those are actually pen-allergic?
10% report an allergy
10% of those are allergic to penicillin
SOGC 247
Penicillin allergy is reported in what percentage of patients? How many of those are actually pen-allergic?
10% report an allergy
10% of those are allergic to penicillin
SOGC 247
What is the incidence of maternal alloimmunization?
0.4 per 1000 births
1-2% of Rh negative women
SOGC 133
What is the incidence of maternal alloinmunization if Rh negative women did not receive:
1) Postpartum prophylaxis?
2) Antenatal prophylaxis?
1) 12-16% of women would become sensitized during the next pregnancy
2) 1.6-1.9% of women would become sensitized
SOGC 133
What is the incidence of maternal alloinmunization if Rh negative women did not receive:
1) Postpartum prophylaxis?
2) Antenatal prophylaxis?
1) 12-16% of women would become sensitized during the next pregnancy
2) 1.6-1.9% of women would become sensitized
SOGC 133
How much fetal blood does WinRho 30ug IM x 1 cover?
30mL of fetal blood
(Same as 15mL of fetal red blood cells)
SOGC 133
In what scenario does the patient not require a dose of WinRho 300ug?
- Rh- mother with Rh+ fetus who received WinRho 2 weeks prior to delivery; KB test 35mL
- Rh- mother with ruptured ectopic pregnancy
- Rh- mother undergoing amniocentesis
- Rh- mother undergoing therapeutic abortion at 8 weeks
- Rh- mother undergoing therapeutic abortion at 8 weeks
Only WinRho 120ug required as total fetal blood is less than 3mL
SOGC 133
What is the percentage risk of placenta accreta in a patient with a placenta previa, who has had:
1) 1 cesarean section?
2) 2 cesarean sections?
3) 3 cesarean sections?
4) more than 4 cesarean sections?
1) 11%
2) 40%
3) 61%
4) 67%
SOGC 361
To prevent risks of neonatal respiratory distress, an elective cesarean section should only be done after what gestational age?
39+0 weeks
SOGC 361
What is the most common indication for cesarean section?
30% of all CS are for previous cesarean sections
SOGC 382
Name 5 contraindications for TOLAC.
Contraindications for TOLAC
• Previous or suspected classical CS
• Previous inverted T or low vertical uterine incision
• Previous uterine rupture
• Previous major uterine reconstruction (e.g full-thickness repair for myomectomy or repair of mullerian anomaly/corneal resection)
• Woman requests elective repeat CS (ERCS) rather than TOLAC
SOGC 382
Name a few factors that increase the chances of a successful VBAC and a few factors that decrease the chances of a successful VBAC. (5 of each)
Factors that improve likelihood of VBAC Maternal ○ Age <=30 years old ○ BMI <30 ○ Caucasian Obstetric ○ Previous vaginal birth *** Best odds ratio ○ Previous CS indication not dystocia ○ Spontaneous labor ○ Bishop Score >=6 on admission Fetal ○ Birth weight <4000g
Factors that decrease likelihood of VBAC Maternal ○ Age >= 35 years old ○ BMI > 30 ○ Preeclampsia Obstetrics ○ Previous CS indication is dystocia ○ Need for induction of labour requiring cervical ripening ○ Need for augmentation of labour Fetal ○ Birth weight >4000g Gestational age >40 weeks
SOGC 382
What is the most independent predictor for succesful VBAC?
Previous vaginal delivery
(86.7% vs 60.9%)
VBAC rates increase with increasing number of prior VBACs • 63.3% after 0 VBAC • 87.6% after 1 VBACs • 90.9% after 2 VBACs • 90.6% after 3 VBACs • 91.6% after 4 or more VBACs
SOGC 382
What is the rate of uterine rupture in patients who have had a previous CS?
0.3%
In TOLAC, 4.7 per 1000 or 0.47% vs elective repeat 0.26 per 1000 = 0.026%
SOGC 382
What is the risk of uterine rupture in a patient who has had:
1) a previous classical CS
2) Interdelivery interval <18 months
3) induction of labor
4) use of PGE2
5) use of misoprostol?
1) 4 to 9%
2) up to 5%
3) 1.4%
4) 2%
5) 6%
SOGC 382
True or False.
External cephalic version is contraindicated in a women who had a previous CS birth
False.
ECV is not contraindicated
SOGC 382
What is the risk of placenta previa after previous cesarean sections?
Risk of placenta previa
• 1 prior CS = 1%
• 2 prior CS = 2.6%
• 3 or more prior CS = 3.0%
If patient has 3 or more prior CS AND placenta previa, risk of placenta accreta is 50-67%
SOGC 382
What is the earliest sign of uterine rupture?
Abnormal fetal heart tracing
Will typically appear 30 mins prior to rupture
SOGC 382
The risk of congenital anomalies related to long-term diabetic control is:
1) for HgB A1C <7%
2) for HgB A1C 7-9%
3) for HgB A1C 9-11%
4) for HgB A1C >11%
1) no increased risk (baseline risk is 2-3 %)
2) 15%
3) 23%
4) 25%
Berghella Obs p. 7
What is the recommended weight gain in the following BMI?
1) <18.5
2) 18.5-24.9
3) 25.0-29.9
4) >= 30
1) 12.5-18kg (27-40lbs)
2) 11.5-16kg (25-35lbs)
3) 7.0-11.5kg (15-25lbs)
4) 5-9kg (11-20lbs)
Berghella Obs p. 20
What is the most common birth defect?
Structural cardiac anomalies
8/1000 births
If mother has a cardiac anomaly, risk to have a child with anomaly is 5-6%
If father, risk is 2-3%
Second most common birth defects are neural tube defects
Williams Obs p.275
Name 5 risk factors for fetal aneuploidy based on maternal history.
- Maternal age
- Previous pregnancy affected by aneuploidy
- Maternal or paternal chromosome rearrangements with increased risk for chromosomal imbalance
- Hx of congenital anomalies
- Recurrent spontaneous abortions NYD
SOGC 348
What is the cut-off for abnormal nuchal translucency at 11+3 to 13+6 weeks?
3.5mm
If higher than 3.5mm, it should be considered a major marker for fetal chromosomal and structural anomalies
SOGC 348
Name two factors that affect the fetal fraction in NIPT screening.
- Gestational age
Between 11 and 14 weeks, fetal fraction 10%
Not recommended before 10-11 weeks - Maternal obesity
For women >110kg, failure rate of cfDNA >10%
Possibly due to dilutional effect
SOGC 348
What is the false positive rate of NIPT? Name 5 possible reasons for this.
False positive rate 1% Reasons: 1. Confined placental mosaicism (CPM) 2. Maternal aneuploidy 3. Maternal CNVs (copy number variant) 4. Maternal malignancy 5. Co-twin demise
SOGC 348
At how many weeks of gestation can chorionic villus sampling and amniocentesis be performed?
CVS 10-13 weeks
Amniocentesis 14-20+ weeks
SOGC 348
Name soft markers that can be seen during second trimester ultrasound suggestive of T21. (5)
- Thickened nuchal fold
- Intracardiac echogenic focus
- Echogenic bowel
- Ventriculomegaly
- Hypoplastic/absent nasal bone
SOGC 348
What is the most common non-obstetrics infection during pregnancy?
Pneumonia
Also the third most common cause of indirect obstetric death
Maternal mortality is 10%
SOGC 225
What are the most common fetal complications that arise from maternal pneumonia during pregnancy?
- Prematurity (most common!)
- Preterm labour
- IUGR
- Neonatal demise
- IUFD
SOGC 225
Optimizing glycemic control in GDM has been shown to decrease which outcomes?
PET
LGA
shoulder dystocia
C-section rate
SOGC 393
How should GDM screening be performed in a patient with prior bariatric surgery?
standard 2-step at 24-28weeks in addition to HbA1c
SOGC 393
When should screening for GDM occur in a patient with risk factors?
2-step approach in the 1st half of the pregnancy with repeat 2-step approach at 24-28weeks if initial testing normal.
RFs:
- age ≥35
- obesity
- ethnicity: AA, Asian, Hispanic
- previous macrocosmic or GDM
- fam hx of DM
- PCOS, acanthosis nigricans
- Corticosteroid use
SOGC 393
When should ultrasound assessment be initiated for patient with GDM?
28 weeks, then q3-4 weeks
Fetal surveillance for GDM should begin at 36 weeks and be performed weekly. What tests should be done?
NST
NST + AFI
BPP
all correct
SOGC 393
What is the timing for IOL for GDM?
38-40 weeks
SOGC 393
What test should be done for postpartum diabetes testing in patient with a history of GDM?
75g. (not 50g)
6weeks-6 months postpartum
SOGC 393
What is the incidence of abnormal diabetes testing postpartum for patients with history of GDM?
1 in 3
SOGC 393
What is the incidence of diabetes later in life for patients with history of GDM?
15-50%
SOGC 393
What are the effects of breastfeeding for 6months in a patient with a history of GDM?
- decrease risk of neonatal hypoglycaemia
- decrease risk of childhood obesity
- decrease risk of maternal DM
- reduce maternal hyperglycaemia
SOGC 393
Patient with GDMA2 received Beta. How should insulin be adjusted?
- Day 1: increase night insulin by 25%
- Day 2 & 3: increase all insulin by 40%
- Day4: increase all insulin by 20%
- Day 5: increase all insulin by 10-20%
- Day 6-7: taper insulin to pre-beta doses
SOGC 393
Does GDM testing meet criteria of a screening test?
No
SOGC 393
Which method of testing for GDM is preferred?
1-step or 2-step both acceptable
The Centre need to pick one and be consistent
No method is superior, no RCT done to compare
SOGC 393
What maternal comorbidities are associated with obesity?
cardiac, OSA, CKD, DM, DLP, NAFLD, Depression, VTE
SOGC 393
What antenatal complications are associated with obesity?
SAB RPL >1 visit for anatomy scan decreased detection of cfDNA increase in fetal anomalies GDM gHTN, PET
SOGC 391
What neonatal complications are associated with obesity?
hypoglycemia, MAS, NICU admission, jaundice, mortality
SOGC 391
What childhood complications are associated with obesity?
obesity
cardiovascular
DM
SOGC 391
What fetal anomalies are associated with maternal obesity?
NTD, cardiac, omphalocele, anencephaly, cleft palate, anal atresia
SOGC 391
What obstetrical complications are associated with maternal obesity?
increased CS(plan and ER), IOL, failed induction, failed VBAC, shoulder dystocia, failed cfDNA, PTB increased scans for anatomy (75% BMI 35, 40% BMI 40+), failed cFHRM / need scalp electrode
SOGC 391
What fetal complications are associated with maternal obesity?
anomalies*, macrosomia, LGA, IUFD, fetal distress
*= NTD, cardiac, omphalocele, anencephaly, cleft palate, anal atresia
SOGC 391
What investigations should be planned during a prenatal visit of an obese patient?
CBC, ferritin, B12 Creat, LFT, TSH HbA1c EKG Cardiac echo (if HTN ≥5yr) OSA Screening Questionnaire (Berlin)
SOGC 391
What interval between bariatric surgery and pregnancy should you recommend?
24 months
- need to wait 24months after bariatric surgery (<2yr= increased NICU, PTB, SGA) - patients are at risk of nutritional deficiencies, GI bleed, anemia - patients are at risk of volvulus, internal herniation, obstruction - bariatric surgery decreasing PET risk by 50%, HTN by 75%
SOGC 391
At what BMI should you recommend medical treatment of obesity?
≥30. or ≥27 with comorbidities.
Orlistat = blocks lipase= prevents dietary fat breakdown Liraglutide = GLP1 R stimulator = suppresses appetite, reduces gastric emptying
SOGC 391
What is the estimated incidence of OSA in the obese pregnant population?
15%
SOGC 391
What supplements are recommended for the obese pregnant patient?
- screen HB, MCV, ferritin, B12
- folic acid 400mg (enough in Materna)
- Calcium carbonate 2500mg (need 1-2g supplement)
- vit D 400 IU (enough in Materna)
- ASA if BMI >30 and nulliparous
- omega3, fish oil, probiotics, mayo-inositol = insufficient evidence
SOGC 391
In what circumstances would an obese pregnant patient require ASA supplementation?
BMI ≥30 AND one of the following:
- nulliparous
- interpregnancy interval ≥10yr
- socioeconomic factors (AA, low SES)
- age ≥35
- previous SGA
- Fam hx of PET
SOGC 391
What are the indications for ASA supplementation?
≥1 RF:
- hx of PET
- chHTN
- autoimmune (SLE, APLS)
- renal disease
- multifetal gestation
- DM 1 or 2
≥2 RFs:
- BMI ≥30
- nulliparous
- interpregnancy interval ≥10yr
- socioeconomic factors (AA, low SES)
- age ≥35
- previous SGA
- Fam hx of PET
SOGC 391
What is the nutritional advice for a pregnant obese woman?
- good sleep hygiene
- ideally nutritionist consultation
- T1 = 100cal extra (2100), >20wk = 300 cal extra (2400)
- carbs 40-55% (High quality, min processed)
- fat 25-30% (monounsaturated ideally); saturated should be 10%
- protein 60g/day = 20-25% of daily caloric intake
- Fiber 20-35g/day
SOGC 391
What is the weight loss % associated with improved maternal and fetal complication in an obese patient planning pregnancy?
5-10%
SOGC 391
What are the consequences of excessive weight gain in pregnancy?
- LGA, macrosomia
- gHTN, PET, DM
- operative delivery
- PP weight retention
SOGC 391
What is the counselling regarding exercise that you can provide for your obese pregnant patient?
- Rule out contraindication for exercice/ PARmed-X questionnaire. http://www.csep.ca/cmfiles/publications/parq/parmed-xpreg.pdf
- Advice:
- structured walking
- start T2 early, 3x/week, 25min, increase 2min per session until 40min per session
- need to do 11000 steps daily
- age 20-29: aim HR=100-125; age 30-39: aim HR 100-120
- avoid vigorous activity, risk of falling, balance loss, abdo trauma
SOGC 391
What is the percentage of patients with BMI >40 who complete their anatomy US in 1 sitting?
40% for BMI ≥40
75% for BMI ≥35
Most difficult to visualize: face, genitalia, extremities
SOGC 391
What are some strategies to improve anatomy US for obese patients?
- vaginal US
- ask the patient to sit and scan from above umbilicus
- ask the patient to sit sideways and scan from flank or groin
- ensure full bladder
- increase signal-to-noise ratio
- use the umbilicus as an acoustic window
SOGC 391
what is the timing of IOL for BMI ≥40?
39 weeks
- Unfavourable cervix and IOL are more common with obesity
- Cervidil (PGE2) less likely to achieve Bishop 6, more likely to require multiple doses
- balloon doesn’t seen to increase risk of failed IOL
- increased incidence of failed induction (BMI dependant)
SOGC 391
What are some theories regarding underlying mechanisms for IUFD in the obese population?
underlying HTN
increased risk of anomalies or genetic defects
increased predisposition to infection
supine position (more weight on uterus and IVC)
underlying OSA
SOGC 391
What is the recommended pregnancy weight gain for a patient with BMI 37?
7kg
Suggested weight gain:
- underweight (BMI <18.5): 12-18kg
- normal weight (BMI 18.5-25): 11-16 kg.
- overweight (BMI 25-30): 7-11 kg
- obese (BMI ≥30): 7kg
SOGC 2018 obesity guideline
What is the WHO classification of obesity?
Based on BMI class 1: 30-35 class 2: 35-40 class 3: 40+
SOGC 2018 obesity guideline
What are some particularities about labour in the obese population?
- longer 1st stage, increased CS 1st stage, dysfunctional labour pattern
- VE more difficult
- CFHRM if BMI >35
- intrauterine pressure catheters are no recommended, but considered
- decision-to-delivery and decision-to-incision increased by 5 min, still within 30min
- more augmentation required
- dystocia: increased
- failed VBAC increased
SOGC 392
What are some considerations about C-section intra-operative and postoperative management in the obese patients?
Incision: consider supra umbilical transverse
Increased wound infection, dehiscence; ancef 3g
2 layer closure
No evidence for JP, PICO dressings, prolonged abx
Patients to inspect, keep dry
DVT prophylaxis
SOGC 392
Are obese patients candidates for intermittent auscultation in the absence of other risk factors?
CFHRM recommended for BMI ≥35
SOGC 392
What is the risk of regional anesthetic failure in a patient with BMI >35?
Anesthesia
- greater risk of regional anesthestetic failure (about 10% if BMI >35)
- more likely to experience hypotension with decels post epidural
- higher risk of aspiration; more restriction on PO intake
SOGC 392
What are some of the aetiologies for decreased breastfeeding in the obese population?
- less likely to initiate BF, initiate BF later, less exclusive BF, shorter duration
- less latching
- decreased lactogenesis
- more CS
- more separation (bb in NICU)
- larger breasts
SOGC 392
What are the preferred postpartum contraceptive methods in the obese population?
45% use contraception at 12mo PP
IUD (hormonal, copper) - acceptable, effective; more challenging insertion
DMPA- safe; less preferred by pt due to weight gain, menstrual irregularities
E2 contraception:
-not given PP due to VTE risk
-need to review other VTE risk factors
-might have less serum drug level
-aim for 20-30ug ethinyl estradiol
Transdermal patch- same as E2
-may have reduced efficiency; can consider if don’t mind failing
Ring - same as normal BMI
HSC tubal occlusion- good; not in Canada
Implants- good, no wait gain; not in Canada
SOGC 392
Why is T1 CRL better than LMP at determining GA?
- irregular cycles
- ovulation time assumed in middle of cycle
- fertilization time assumed in middle cycle
- correct recall of LMP
- off OCP x several months- periods not regular
- ovulation-to-implantation duration can vary by as much as 11 days, affecting size and growth
- LMP underestimates EDC by 2-3 days
SOGC 388
What is the greatest advantage of GA determined by T1 US rather than LMP?
Decreased incidence of IOL for PD.
SOGC 388
T1 US dating is chosen rather than LMP when the difference in number of days is greater than ___
Tricky question.
0 days.
T1 US dating should always prevail over LMP.
SOGC 388
What dating is more accurate than T1 dating?
IVF implantation date
SOGC 388
What is the earliest T1 US that can be used for dating?
7 weeks or CRL ≥10mm.
If two T1 US done, use the earliest.
GS can be used, less reliable when embryo can be identified
CRL has less inter observer variability than GS
YS should not be used for dating; max size 6mm by 10wk
SOGC 388
What is the best measure to estimate GA between 12-14 weeks?
CRL or BPD
SOGC 388
What is the best measure for estimating GA when CRL ≥84mm?
BPD
SOGC 388
What measurements can be used to estimate GA at the anatomy US?
need combination of BPD, HC, FL, AC; no added benefit with extras
- most accurate: HC - least accurate: AC (breathing, position) - FL = ethnic variations
SOGC 388
What elements should be visualized in order to obtain an accurate estimation of the BPD?
plane including CSP, 3rd ventricle, thalami, falx cerebrum, tectorial hiatus
measure outer to inner
SOGC 388
What elements should be visualized in order to obtain an accurate estimation of the FL?
visualize femoral head, trochanter, condyle;
no epiphysis;
SOGC 388
8 week US- if GA better estimated by TA or TV US?
TA vs TV = previously increase accuracy with TVUS, now evidence that they are similar if CRL >6wk
SOGC 388
What are some advantages of T1 US in addition to dating?
- confirm IUP, multiple gestation;
- early detection of major anomalies
- opportunity of NT
- decreased IOL for PD
- improved sensitivity for screening
- better peri-viability dating
SOGC 388
What were the findings of the Term Breech Trial?
2000, RCT
◦ Low-PNM countries: no difference in PNM; but short term neonatal morbidity 0.4 vs 5% (CS vs breech SVD)
◦ 2yr follow-up: no difference in neurological status;
Limitations: multiple countries including countries with high PNM, context not applicable to Canada; IUGR and macrosomia included- lack of routine US (7/16 perinatal deaths were in IUGR babies); protocol allowed for slow labour progress (0.5cm/hr 1st stage, 3.5h second stage)
SOGC 384
Comment on the risk of perinatal mortality, CP, and neurological outcomes in vaginal breech and planned CS
CP outcomes same between breech SVD and CS
prenatal mortality low in both, slightly higher with breech SVD (0.8-1.7 vs 0-0.8 per 1000)
long-term neurological outcomes are similar
short-term neurological morbidity worse with breech
SOGC 384
What is the role of US for a term planned vaginal breech delivery?
◦ type of breech
◦ flexion of head
◦ fetal growth- if no recent US
SOGC 384
What are the contraindications to vaginal breech delivery?
◦ contraindications to SVD
◦ IUGR
◦ Macrosomia >4000g
◦ Inadequate pelvis (no pelvimetry, but good labour progress= good pelvis)
◦ Hyperextended head
◦ Non-frank/complete breech (footling, cord first)
SOGC 384
Comment on the role of synto for breech deliveries for IOL and augmentation.
1) IOL not contraindicated, but evidence is limited
2) augmentation with synto is acceptable, but one should have a low threshold for CS if FTP is suspected
3) consider after delivery of the body to assist with head delivery since contractions might slow after body is delivered
SOGC 384
What is the maximum duration to go from 5 to 10cm in a vaginal birth delivery?
7 hours
in the Term Breech Trial, only 1.4% of patients needed more than 7hours to go from 5 to 10cm. if slower than 5cm, suspect CPD and a difficult breech –> CS
SOGC 384
What is the maximum duration of passive 2nd stage of labour for a breech vaginal delivery?
90min
SOGC 384
What is the maximum duration of active 2nd stage of labour for a breech vaginal delivery?
60min
SOGC 384
What is the Loveset Manoeuver?
assist with deliveries of the arm
SOGC 384
What forceps are used for assisting with an entrapped head during a vaginal breech delivery?
Piper forceps
SOGC 384
What is the Mauriceau-Smellie-Veit manoeuver?
Delivery of the fetal head by applying suprapubic pressure and fingers on the baby’s mandible.
SOGC 384
What are the maneuvers for a trapped head?
Piper forceps
Nitro, salbutamol, GA
Duhnssen’s cervical incision: 2,6, 10 o’clock
symphisiotomy or Zavanelli
SOGC 384
What is the biggest risk factors for placenta accreta?
- Previa (OR 292)
- AMA >35. (OR 4.6)
- IVF (OR 3.1)
- CS: 1 prior OR 6.6, 2 prior OR 17.4, 3 prior OR 56
- minor uterine sx such as HSC, D&C. OR 3.4
- case reports: myomectomy, UAE, asherman’s
SOGC 383
What is the sensitivity and specificity of ultrasound to diagnose placenta accreta?
US: SEN 90.7%, SPEC 96.9%
MRI: SEN 94%, SPEC 84%
SOGC 383
At what GA should placenta accreta be delivered?
34-46wk
Plan for corticosteroids
SOGC 383
What multidisciplinary teams should be involved in the prenatal care of placenta accreta?
OB anesthesia MFM Designed team (gyn, onc, specific staff) for accreta Radiology NICU
SOGC 383
In addition to Ancef, what other medication should be given at time of surgical timeout for placenta accreta?
TXA
Ancef to be repeated after EBL >1.5L
SOGC 383
What incision is preferred for management of placenta accreta?
midline
classical uterine incision
SOGC 383
What urological arrangements should be made in the context of placenta accreta?
3-way catheter
methylene blue available
consider intermittent filling of the bladder
no routine use of cystoscopy, consider having in OR
no routine use of ureteric stents
SOGC 383
Which techniques can assist with significantly decreasing blood loss during a caesarean hysterectomy for placenta accreta?
TXA at OR timeout IIA balloons- evidence is mixed 1 layer uterine closure do not attempt to remove the placenta use of cell salvage avoid GA
SOGC 383
What percentage of patients with placenta accreta spectrum in which conservative management was chosen with placenta left in situ will subsequently require emergency hysterectomy?
40%
SOGC 383
What is the estimated percentage of recurrence in patients treated conservatively for placenta accreta?
15-27%
SOGC 383
Which medications are required during the first 24h postpartum after C-hyst for placenta accreta?
LMWH
No evidence for routine antibiotics, TXA
SOGC 383
How do you manage placenta accreta treated conservatively with placenta left in situ?
- clamp, short cord with absorbable suture, IV abx
- NPO x12-24h, as possible need for OR
- devascularization, f-u q week x 4-6wk
- 40% need hyst, 40% major complications
- acceptable method of delivery bt is associated with protracted course of recovery and persistent need for hysterectomy
SOGC 383
Which document should a patient with placenta percreta carry with her?
a patient letter in case of emergency
SOGC 383
What is the definition of microcephaly?
HC 3 SD below mean
SOGC 380
What are the infections causing microcephaly and which one is the most common?
CMV ** Syphillis Toxoplasmosis Rubella Herpes HIV Zika
SOGC 380
What are the aetiologies for microcephaly?
genetic
infectious (TORCH, HIV, Zika, Syphillis)
exposure (smoking, radiation, alcohol, arsenic, mercury)
SOGC 380
Which toxic exposures have been linked to microcephaly?
arsenic mercury EtOH smoking radiation
SOGC 380
What is the required work-up for microcephaly?
TORCH detailed brain US (3ry care) fetal MRI 3 generation family tree parental HC detailed history: exposure, substance use, comorbidities genetic consultations serial US
SOGC 380
What percentage of US women who deliver at home consume their placenta
1 in 3!
SOGC 378
What are the nutritional components of the placenta?
- no heavy metals
- iron (less than goose liver; more than ground beef)
- minerals: only trace
- hormones (estradiol, progesterone)- likely low levels post dehydration
SOGC 378
Rats placenta express POEF (placenta opioid enhancing factors). this is associated with which benefits for rats?
pain relief
adaptive maternal behaviour
SOGC 378
What are potential harms of placentophagy?
Lack of standardization of placental processing
Case reports of GBS sepsis / risk of blood born organisms infections
Lack of sterilization
SOGC 378
What percentage of the Canadian population is rural according to SOGC?
20%
SOGC 379
What are the conditions to be met by a community maternity centre?
availability of:
- informed consent decisions
- obstetrician consult over phone
- ER OB meds: beta, Mg, adalat, uterotonics
- access to transport
SOGC 379
What is the difference between Emergency and Urgent C-section?
Emergency <30min:
cord prolapse
abnormal FHR
abruptio
Urgent <75min
FTP
FTD
atypical FHR
SOGC 379
What are the pregnancies that can be delivered in a T1A centre?
1A is basic- cannot do CS. only 36+ with no issues 37wk minor issues singletons no VBAC
SOGC 379
What are the additional aspects of care for T4 compared to T3 centres?
multidisciplinary/specialized neonatal care (although 3b can have neonatal surgical capacities)
conditions that are life-threatening for mother or baby
SOGC 379
Which negative outcomes increase with CS for FTD compared to other CS?
PPH
extensions
Future pregnancies:
risk of accreta
risk of cervical insufficiency
risk of PTB <30wk
SOGC 381
What are some interventions shown to promote SVD and avoid instrumental delivery?
one-to-one labour support synto IA rather than CFHRM for low-risk manual rotation OP/OT to OA delayed pushing extended pushing (3h nulliparous, 2h multiparous)
SOGC 381
What are the requirements for AVB?
pain control empty bladder position known mid or outlet station consent obtained availability of CS (plan B) operator skilled
SOGC 381
What are some maternal indications for AVB?
cardiac disease NYHA III/IV Severe respiratory disease Proliferative retinopathy Neuro disease (Myasthenia Gravis, Autonomic dysreflexia) Cerebral AVM
SOGC 381
What are some fetal indications for AVB?
abnormal FHR
no descent
SOGC 381
What are some contraindications for AVB?
suspected fetal coagulopathy or brittle bone disease mid or high station unknown position suspect CPD no access to CS
not mentioned in guideline, but: HIV, HepB
SOGC 381
What are the classifications of stations for AVB?
HIGH = above spines MID= 0 to +2 LOW = +2 or higher OUTLET = skull visible at intraoitus without separating labia
SOGC 381
What are risk factors for failed AVB?
EFW > 4000
BMI >30
OP/OT
MID
SOGC 381
What are the maternal risks for AVB? (compare to emergency CS)
lower genital tract injury, OACIS vaginal hematomas urinary injury, subsequent incontinence psychological sequelae perineal pain
SOGC 381
What are the increased risks of CS compared to AVB?
PPH
increased LOS
increased neonatal admission
SOGC 381
What are the fetal risks of AVB?
shoulder dystocia intracranial bleed rare 1:1000 (same for vacuum=forcep=CS) retinal hemorrhage (regardless of mode of delivery including CS but potentially more with AVB)
vacuum: cephalophematoma
forceps: facial abrasion, facial nerve palsy <1%, ocular trauma 2%
SOGC 381
What are the steps to take after AVB?
DOCUMENT DEBRIEF with family examine neonate: face, head PVRs if voiding dysfunction suspected antibiotics if OACIS LMWH only if other RF
SOGC 381
How can STI screen be done for a 24yo sexually active woman?
urine NAAT (as good as the culture)
self-collected culture
physician-collected culture (not necessary)
pelvic exam not needed (unless symptoms- then its diagnostic not screening exam. detect PID, TOA)
SOGC 385
What physical examination steps have to be taken prior to OCP prescription?
only BP measure
(and history)
pelvic exam not needed in an asymptomatic woman
SOGC 385
What examination needs to be done prior to HRT prescription?
pelvic exam and vulvar/perineum/anus inspection
differentiating between normal ageing and pathology might not be obvious for the patient
examination for vulvar cancer always important since it is the gyn malignancy with biggest delay in diagnosis
SOGC 385
What gyn exams should be done after 70yo?
providing N Pap tests so far (if not normal or none done recently, do Q3yr x2 negative results)
needs to screen for vulvar cancer with
inspection of vulva/anus/perineum
(frequency of visits for specified)
SOGC 385
In addition of cervical cancer, screening should be done for which other gyn malignancy?
vulvar
- biggest delay in diagnosis
- external inspection of vulva/anus/perineum
- frequency not specified after 70yo; prior to 70yo, during Pap test screening exams.
SOGC 385
Why should you do a speculum exam in woman with T1 bleeding if the US already showed incomplete SAB?
1) remove RPOC from cervix to decrease:
- pain
- bleeding
- vagal reaction
2) rule out other causes of PVB
SOGC 385
A woman mentions new GI symptoms (eg. severe constipation) during gyn visit. Why should you do a pelvic exam and what should it include?
inspection, speculum, bimanual, rectovaginal
reasons:
- deep infiltrating endo
- POP
- gyn malignancy
SOGC 385
Which gyn patients should have pelvic exams more frequently than q3yr?
previous abnormal tests
symptomatic
immunocompromised
DES exposure history
genetic predisposition (they mention this in the guideline but technically controversial)
personal history of gyn malignancy
SOGC 385
What is the preventive role of screening of gono/chlam?
prevent:
PID
infertility
chronic pain
SOGC 385
Which provinces removed restrictions on physicians attending homebirth?
ON and BC
SOGC 372
What are the requirements for midwifes doing home births?
First of all these patient have to be selected
Ongoing risk assessment
Hospital privilege
Emergency equipemtn
Emergency transport system
Assistant at time of birth (qualified provider)
SOGC 372
A meta-analysis of 4 studies in BC and ON including 21900 homebirths vs 23500 hospital births showed what fetal outcomes
No difference in : neonatal death <28d perinatal death APGARS <7 at 5min NICU admission severe neonatal morbidity
*all these outcomes are rare
SOGC 372
A meta-analysis of 4 studies in BC and ON including 21900 homebirths vs 23500 hospital births showed what maternal outcomes
More: SVD (91% vs 85%)
Less:
- CS, IOL, augmentation, AVB
- OASIS, episiotomy
- infection
- pharmacologic pain relief
SOGC 372
What is the incidence of cerebral palsy at 23-27wk?
9%
SOGC 376
When should you follow Mg levels when Mg is prescribed for neuroprotection?
no routine measure unless CKD/AKI
need to measure Creatinine
no need for foley
SOGC 376
How does maternal care differ between Mg for PET and Mg for neuroprotection?
No routine labs if creatinine is normal
No need for foley
Stop at delivery
SOGC 376
What is the mechanism of action of MgSo4?
- cerebral vasodilation
- reduction in inflammatory cytokines
- reduction in oxygen free radicals
- inhibits Ca++ influx into cells
SOGC 376
What is the NNT for MgSo4 to prevent one case of Cerebral Palsy at 30wk?
50s 28-34wk
30 <28wk
SOGC 376
What are the maternal side effects of MgSo4
flushing 70% pain at IV site N&V sweating 25% hypotension 10% tachycardia respiratory depression 2% pull edema 0.7%
SOGC 376
What are the maternal contraindications to MgSO4
myasthenia gravis
MgSo4 sensitivity
hepatic coma
SOGC 376
What are the effects on immediate NICU care at delivery for babies having received MgSo4?
Decreased need for intensive resuscitation
No change for: need for prolonged ventilation Apgars <7 at 5min neonatal hypotonia need for resuscitation
SOGC 376
What is the maternal treatment for suspected MgSo4 toxicity?
Calcium gluconate
SOGC 376
What are the neurological deficits associated with PTB?
-CP ◦ motor impairment ◦ Blindness ◦ Deafness ◦ Dev delay ◦ Cognitive delay ◦ Poor academic performance ◦ Behavioural disorder
SOGC 376
What is the incidence of PTB <32wk?
1.2%
SOGC 376
What is the incidence of CP?
‣ 2-2.5 per 1000 births
‣ Umbrella term to describe mov and posture disorders +- epilepsy, cognition, perception, beh problems ‣ Reliably diagnosed by age 2 ‣ GA-related risk is associated with weight <1500g, white mater injury ‣ Multiples are at increased risk ‣ No cure, prevention is key; Cost+++
SOGC 376
What is the benefit of repeating course of MgSo4
unclear
no evidence to repeat
SOGC 376
What is the benefit of bolus+ maintenance vs only bolus for MgSo4 for neuroprotection?
none
suggested to give maintenance in order to maintain same standard as with PET, prevent errors
Also no difference with prolonged use vs only 4h
SOGC 376
Why should MgSo4 for neuroprotection and adalat tocolysis given together?
as per guidelines:
- because we should only give MgSo4 if delivery is imminent
- we cannot give tocolysis if delivery is imminent
can start MgSo4 once adalat stopped
only case reports of neuromuscular blockade
they don’t discuss pulmonary oedema
SOGC 376
What is the name of the theory by which progesterone can help reduce risk of spontaneous preterm birth?
Csapo theory:
high progesterone levels prevent uterine contractions and low levels facilitate contractions
SOGC 398
What are the indications for treatment with progesterone during pregnancy for the prevention of spontaneous preterm birth?
- History of preterm birth
- Short cervix (<= 25mm on TVUS) between 16 and 24 weeks
If women have a hx of cold knife cone, LEEP, uterine anomalies, should not be prophetically treated with progesterone. Only if short cervix on TVUS.
Reduced risk of PTB <34 weeks (OR 0.43, NNT 9)
Reduced risk of PTB <37 weeks (OR 0.51, NNT 7)
Decreased risk of neonatal death (OR 0.41, NNT = 30)
SOGC 398
What % of women who have had previous spontaneous preterm birth had short cervix?
20%
Alternatively, 30% of women with short cervix have a history of previous preterm birth
SOGC 398
What is the dose of progesterone suggested for prevention of preterm birth in singleton pregnancy? In multiple gestation?
Progesterone 200mg PV qHS in singletons
Progesterone 200mg PV BID in multiple gestations
SOGC 398
TRUE or FALSE.
Vaginal progesterone is as safe and as effective intramuscular progesterone.
FALSE.
There is increase risk of adverse neonatal outcomes for IM progesterone
SOGC 398
When should progesterone treatment for reduction of spontaneous preterm birth begin? Up to when?
Start between 16-24 weeks, up to 34-36 weeks of gestation depending on the case.
SOGC 398
Administration of antenatal corticosteroids is recommended in women at high risk of delivery between what gestational age?
Between 24 and 34+6 weeks of gestational age, when high risk of delivery within 7 days
SOGC 364
In order to reduce risks of neonatal respiratory distress, elective CS should not be performed prior to how many weeks gestation?
39+0 weeks of gestation
Alternatively, if booked for CS between 37-38+6 weeks, should not routinely administer corticosteroids
SOGC 364
What are the 2 different corticosteroids that have been studied for use in pregnant women and what are their dosages?
Dexamethasone 6mg IM q12 hours x 4 doses
Betamethasone 12mg IM q24 hours x 2 doses
SOGC 364 - Table 7
TRUE or FALSE.
Once corticosteroid was deemed necessary, the entire first course should always be completed.
False.
In cases where the first dose of antenatal corticosteroid therapy has been administered and then reassessment suggests that delivery within the next 7 days unlikely, cancellation of the second dose should be considered
SOGC 364
After how long should a rescue course of corticosteroid be considered when patients are at high risk of preterm delivery?
After 2 weeks (14 days)
SOGC 364
In women who received corticosteroid for lung maturity, screening for gestational diabetes should be delayed by how long?
A minimum of 1 week.
Do the 75g OGTT test directly.
SOGC 364
