Obstetrics Guidelines Flashcards
1
Q
Benefits of delayed cord clamping in the preterm infant
A
decreased rates of blood transfusion
decreased IVH
decreased sepsis
2
Q
Benefits of T1 U/S
A
confirm viability accurate dating identification of multiples determination of twin chorionicity early detection of major structural anomalies aneuploidy screening (NT)
3
Q
Risks associated with large NT
A
aneuploidy congenital heart disease fetal akinesia structural malformations single gene d/o (ie. noonan's) poor pregnancy outcome (ie. IUFD)
4
Q
What minimum fetal fraction do you need to accurately perform NIPS?
A
> 10%
5
Q
Factors affecting fetal fraction rates
A
GA
Maternal obesity (inversely related to ff)
Chromosome aneuploidy in placenta or mother
6
Q
What are LR for each of these soft markers:
- inc. nuchal fold
- EICF
- CPC
- echogenic bowel
- mild ventriculomegaly
A
inc nuchal fold: 17 EICF: 2 CPC: 7 (only T18) echogenic bowel: 6 mild ventriculomegaly: 9
7
Q
Increased risks associated with echogenic bowel other than aneuploidy
A
- CF
- fetal infection
- GI malformations
8
Q
Presence of isolated increased nuchal fold on T2 U/S should not be used to adjust a priori risk for T21 (T/F)
A
False! Only NF would cause to adjust risk, isolated findings of any other soft markers would NOT
9
Q
Which three Chromosomal abnormalities can you recommend screening for in Ashkanazi jewish pop?
A
Tay Sachs
Canavan Disease
Familial dysautonimia
10
Q
Disorders associated with low uE3
A
X-linked ichthyosis Smith-Lemli-Opitz syndrome CAH multiple sulfatase def Antley-Bixler syndrome
11
Q
Increased risks in its with GDM
A
Shoulders CS Prematurity LGA Preeclampsia
12
Q
Risk factors for GDM
A
hx GDM or glucose intolerance family hx of diabetes previous macrocosmic baby px unexplained SB previous neonatal hypoglycaemia, hypocalcemia, hyperbilirubinemia AMA Obesity Polyhydramnios Suspected macrosomia
13
Q
At what GA should you recommend IOL in GDM on insulin? GDM diet controlled?
A
39 weeks
40 weeks
14
Q
What percentage of patients with GDM are diagnosed with T2DM at their PP GCT?
A
1/3
15
Q
What volume of fetal blood is covered by a 300mcg dose of WinRho?
A
30mL (15mL fetal RBCs)
16
Q
List 7 procedures after which you should give Rh prophylaxis
A
- SA/TA
- Ectopic pregnancy
- Molar pregnancy (may be partial)
- Amniocentesis
- CVS
- Cordocentesis
- ECV
17
Q
Incidence of maternal alloimmunization in Canada
A
0.4 per 1000
~1-2% of D-neg women
18
Q
Anti-D does not cross the placenta (T/F)
A
False. Crosses placenta and binds to fetal RBCs without causing hemolysis, anemia or jaundice
19
Q
At what GA is D antigen detectable on embryonic RBCs?
A
7+3w GA
?do not need to give WinRho if SA <7weeks
20
Q
After which GA does the dose of WinRho need to be increased from 120 to 300mcg?
A
12-13 weeks
21
Q
5 absolute C/I to OVD
A
- non-vertex or brow
- unengaged head
- incomplete cervical dilation
- clinical evidence of CPD
- fetal coagulopathy
22
Q
Which of the following is a contraindication to a TOLAC?
a) multiples
b) GDM
c) suspected fetal macrosomia
d) previous myomectomy
e) A+D
A
D only
23
Q
Contraindications to VBAC
A
- px classical, T scar
- previous full thickness hysterotomy/myomectomy
- previous uterine rupture
- C/I to labour
- woman requests ERCS
24
Q
Most common infectious cause of stillbirth
A
Parvovirus B19
25
Most common etiology of IUFD
Placental abruption
26
two ways to induce contractions during a contraction stress test?
nipple stim
| oxytocin infusion
27
what are the components of a modified BPP?
NST + AFI (normal if >5cm)
| If abN, perform complete BPP
28
What is the range of a normal SDVP?
2-8cm (<2 oligo, >8 poly)
29
Indications for Uterine Artery Dopplers at 17-22w
1. Previous early-onset GHTN
2. Hx Placenta abruption
3. Hx IUGR
4. Hx Stillbirth
5. Pre-existing HTN
6. GHTN
7. Pre-existing renal disease
8. T1DM with vascular complications
9. Abnormal maternal serum screening (hcg or AFP >2.0 MoM)
10. Low PAPP-A
30
Obstetrical comorbidities associated with impaired trophoblastic invasion
HDP
IUGR
Abruption
IUFD
31
Four criteria necessary to consider diagnosis of CP
1. Metabolic acidosis in umbilical cord arterial blood (pH <7, BD >12)
2. Early onset of mod/severe NE in infants born >34 weeks
3. CP of the spastic or dyskinetic type
4. Exclusion of other identifiable etiologies
32
ACOG Criteria for intrapartum asphyxia (5)`
1. sentinel hypoxic event immediately before or during labour
2. sudden and sustained fetal brady or absent variability in the presence of persistent, late or variable decals, after sentinel event when pattern px normal
3. Apgars 0-3 beyond 5 mins
4. onset of multi system organ involvement w/in 72h
5. early imaging showing evidence of non-focal cerebral abnormality
33
Area of the brain most likely to be injured during hypoxic even in term infant? preterm?
Term: subcortical white matter, cerebral cortex
Preterm: periventricular white matter
34
benefits of continuous labour support
```
reduced intrapartum pain meds
reduced regional anesthesia
reduced OVD
reduced C/S
increased SVD
reduced reports of negative experience
```
35
Which patient does not require CEFM?
a) epidural
b) IOL w/ oxytocin
c) Healthy multip, GA 42+1
d) VBAC
a) epidural
Recommend CEFM with VBAC, IOL, PD >42w, GA <36w
36
Risks of post-term pregnancy
```
SB
fetal distress
Labour dystocia
OVD
Macrosomia
Shoulders
Lower Apgar scores
Meconium aspiration
```
37
If woman choses expectant management at 41+0, what should you offer for management?
NST and AFV bi-weekly until 42w, then recommend IOL
| ?daily FMC
38
5 C/I to VBAC
1. Cord presentation, placenta previa
2. IUGR/Macrosomia (<2500, >4500)
3. Presentation other than frank or complete breech with flexed or neutral head
4. clinically inadequate maternal pelvic
5. Fetal anomaly incompatible with vaginal delivery
39
What are the components of the APGAR score?
```
Activity (tone)
Pulse
Grimace
Appearance (colour)
Respirations
```
40
Options for management of an after coming head during vaginal breech delivery
- Pipers forceps
- Duhrsens incisions
- symphisiotomy
* give Nitro or terbutaline
41
What is the recommended weight gain/loss during pregnancy for women with a BMI >40
7kg weight gain
42
Which congenital anomalies are increased in obese women?
NTD (2fold)
Cardiac
Ventral wall
Orofacial
43
Four features of children born with FASD
1. prenatal exposure to alcohol
2. growth restriction
3. Facial dysmorphology
4. CNS dysfunction
44
4 main causes of IUGR
1. TORCH infections
2. Aneuploidy
3. Placental insufficiency
4. Congenital anomalies
45
What two options for induction are available for term PROM
1. vaginal PGE2 + ocytocin
| 2. oxytocin
46
How long must you wait before starting oxytocin after cervical ripening with miso? cervidil? prostin gel?
4h after miso, 30 mins after removal of cervidil, 6h after gel
47
Which Korotkoff phase should be used to determine DBP
V
48
How long do you have to wait for neuraxial anesthesia for patient on UFH? prophylactic LMWH? therapeutic LMWH?
4h after last dose of UFH if normal PT
10-12h after last dose of prophylactic LMWH
24h after last dose of therapeutic LMWH
49
What is the best test to diagnose PE in pregnancy?
```
VQ scan
(Ok to do CTPE)
```
50
In a woman with clinical suspicion of DVT in pregnancy, what is the follow-up recommended if compression US is negative
Repeat within 7 days
51
What is the medical management of VTE in pregnancy
Therapeutic LMWH x 3 months, then decrease to prophylactic dose until 6 MONTHS PP
52
What is the management of ovarian vein thrombus in pregnancy? How is it diagnosed?
Broad spectrum IV Abx x 48h afebrile
Therapeutic anticoagulant x 1-3 months
CT/MRI
53
Indications for prophylactic thromboprophylaxis in pregnancy (8)
1. hx unprovoked DVT
2. Hx DVT due to OCP
3. Hx provoked DVT and low risk thrombophilia
4. Asympt. homozygous Factor V Leiden
5. Asympt. homozygous Prothrombin gene mutation
6. Asymptomatic antithrombin deficiency
7. Non-OB surgery during pregnancy
8. Strict antepartum bedrest >7d and BMI >25
54
Most common location for DVT in pregnancy
Left leg iliac or femoral vein
55
What is the most common location for an ovarian vein thrombus?
Right ovarian vein
56
What is the most common location for VTE in patients with OHSS
upper extremity
57
How many days post-conception does the neural tube close?
26-28d (3-4th week)
58
What is the rate of recurrence of NTD in a woman using preconceptual folate? without?
1%, 3.5%
59
Vaccines C/I in pregnancy
```
HPV
MMR
Varicella
Polio (unless going to endemic area)
Yellow fever (unless going to endemic area)
```
60
Obstetrical risks in adolescent pregnancy
1. PTL/PTB
2. PPROM
3. congenital anomalies
4. IUGR
5. PPD
6. Stillbirth
7. NICU admission/neonatal death
61
Advantages of umbilical cord blood stem cell transplantation
1. greater flexibility in HLA matching
| 2. lower risk of GVHD and graft failure
62
Disadvantages of umbilical cord blood stem cell transplantation
1. limited number of stem cells in cord blood specimen
2. delayed engraftment (increased risk of bleeding/infection in recipient)
3. high cost
63
Who is usually the legal custodian of banked umbilical cord blood
mother of baby
64
Complications of OASIS
1. anal incontinance (flatal/fecal)
2. rectovaginal fistula
3. chronic pain
4. dysparunea
65
Risk of recurrence of OASIS
4-8%
66
What are the subtypes of 3rd degree tears?
3a: injury to EAS (<50% thickness torn)
3b: injury to EAS (>50% thickness torn)
3c: both EAS and IAS torn
67
Which is NOT a RF for hyperemesis
a) previous HG
b) female fetus
c) obesity
d) hx of depression
c) obesity
LOW maternal BMI is RF
Also mole, multiples, maternal fam hx
68
Which antiemetic is NOT an H1 receptor antagonist?
a) doxylamine
b) metoclopramide
c) diphenhydramine
d) dimenhydrinate
b) metoclopramide (Dopamine receptor antagonist)
69
What are fetal risks of ondasetron use for NVP? maternal?
fetal: cleft palate, cardiac anomalies
maternal: constipation, bowel obstruction
70
How would you diagnose discordance between twins?
AC deff >20mm
| EFW diff >20%
71
What is the Quintero staging?
Quintero 1: poly/oli sequence, donor bladder visible
Q2: poly/oli sequence, donor bladder not visible
Q3: abnormal dopplers in one/both
Q4: hydrops in recipient
Q5: death of one or both fetuses
72
U/S diagnostic features of mono/mono twin pregnancy
- absence of the dividing membrane
- single placenta
- both fetuses same gender
- adequate AF around each twin
- both fetuses moving freely in the amniotic cavity
73
In a patient with placenta prevue and one previous C/S, what is the risk of accreta?
25%
74
What is the dose of progesterone for prevention of preterm birth in a woman with a hx of PTB? short cx @ 22-26w?
100mg PV OD "prophylactic"
| 200mg PV OD "therapeutic"
75
RFs for vasa previa
IVF
placenta previa
bilobed/succenturiate lobe
Fetal anomalies
76
Benefits of Buprenorphine over Methadone for opiate abusers in pregnancy?
Less sedating
Less risk of OD
Lower incidence of NAS
77
What one chemotherapy drug is not a C/I to breastfeedign
Azathioprine
78
What are the three primary mechanisms associated with hydrops?
Fetal anemia
Fetal heart failure
Fetal hypoproteinemia
79
Management of pregnancy, G1, incidental finding of 2cm cx at 22w U/S?
G2T0P1A0L1 @ 22w with 2cm cx and hx of px del at 28w?
Progesterone 200mg PV OD
| Emergency cerclage
80
Risks of cerclage:
```
Sepsis
PPROM
PRL
Cervical dystocia
Cervical laceration at delivery
Hemorrhage
```
81
Reasons to remove cerclage prior to 36-38w
Preterm labour
Evidence of sepsis
PPROM (after 48h, give steroids first)
82
MgSO4 for fetal neuroprotection, NNT to prevent one case of CP?
mag sulf for eclampsia prevention, NNT?
63, 50
83
What does ALARA stand for?
As Low As Reasonably Achievable
84
What 8 soft markers are evaluated on the anatomy scan
1. Nuchal fold
2. EICF
3. CPC
4. Pyelectesis
5. Ventriculomegaly
6. Echogenic bowel
7. SUA
8. Enlarged cisterna magna
85
When dating pregnancy by U/S for twin gestation, which twin should you use to calculate GA?
Larger twin to avoid missing IUGR
86
What U/S characteristics can you use in T2 to determine chorionicity/amnionicity
1. Fetal genitalia
2. placental number
3. chorionic peak sign
4. membrane thickness
87
Most common congenital malformations in twin pregnancies?
Cardiac, neural tube/brain, facial clefts, GI, anterior wall defects
88
If a woman's viral load is low and CD4 count is high pre-pregnancy, she does not have to start cART in pregnancy (T/F)
False. All pregnant women should be on cART regardless of viral load and CD4 count
89
Is there a risk of neonatal HSV if a woman has a remote history of HSV but no outbreaks in pregnancy and no lesions at the time of delivery?
Yes, 1% risk of asymptomatic shedding
90
How would you manage a woman with hx of HSV, no lesions, PPROM but not in labour?
Start suppressive therapy until delivery
91
What is the most important risk factor for maternal transmission of Hepatitis B
HBV DNA levels
92
What two treatments would you give to a neonate born to a mother with Hep B?
Hep B vaccine (first dose), HBIG within 12h
93
When does the neural tube close? Embryonic age and GA
3rd/4th week embryonic age (21-29d)
| 5-6w GA
94
The majority of NTDs are associated with known syndromes/malformations
False. 70% of NTDs are isolated
