High Risk Obstetrics Flashcards
How does pregnancy affect glucose/insulin?
- Reduced insulin receptor sensitivity
- Decreased gastric motility
maternal hyperglycemia > fetal hyperglycemia > fetal hyperinsulinemia > excess fetal growth
Normal pregnancy - what are the effects on blood sugar?
Hyperinsulinemia
Mild fasting hypoglycemia
Post-prandial hyperglycemia
Which antibodies are consistent with T1 DM?
GAD65 antibodies
IA2
IA2 eta
islet cell TnT8
Criteria for diagnosis of diabetes
HbA1c >= 6.5%
2hr glucose >200 (after 75g load)
Random glucose >200
(repeated twice to confirm)
Criteria for diagnosis of pre-diabetes
Fasting glucose 100-125
2hr glucose 140-199
A1c 5.7%-6.4%
What is the prevalence of diabetes in pregnancy?
T1DM: 0.25-0.5%
T2DM: 1-2%
What are the teratogenic risks of hyperglycemia?
A1c <8.6 - ~2-3%
A1c 9-10% - 6%
A1c 10-10.5 - 9%
A1c >10.6 - 25% risk of congenital anomaly
What are the common anomalies associated with high A1c?
neural tube defect, complex congenital heart defect, caudal regression, renal agenesis
What poor pregnancy outcomes are associated with hyperglycemia?
Miscarriage
Fetal anomalies
Pre-eclampsia
Macrosomia
C-section
Neonatal - shoulder, hypoglycemia, respiratory support, high bilirubin
What are glucose targets?
Fasting < 95
1hr PP <140
2hr PP <120
What does A1c of 6.5% correspond to in blood glucose?
140 mg/dL
What are the two types of implantations of cesarean scar pregnancies?
On the scar - >2mm of myometrial thickness between placenta/gestational sac and bladder
In the niche - <2mm myometrium
How do you diagnose CSP/what are ultrasound findings of CSP?
Positive pregnancy test
Empty uterine cavity, empty endocervical canal
Early gestational sac or placenta in proximity of hysterotomy scar
Absent of thin myometrial layer
Interrupted or deformed bladder line
Abundant blood flow around
What is the pathognomonic sign of CSP?
Low anterior location of placenta, often placenta previa, and increased vascularity at placental/bladder interface
What is the differential diagnosis of cesarean scar pregnancy?
- CSP
- Cervical pregnancy
- Miscarriage in progress close to the os
When do you see placental lacunae?
After 7 weeks; progressively seen in 78% of cesarean scar pregnancies
How common is stroke in pregnancy?
30/100,000 pregnancies.
What’s the recurrence risk of stroke in pregnancy?
1-2% (risk of stroke in pregnancy with h/o stroke)
What is the most common type of stroke in pregnancy?
Ischemic (embolic or non-embolic)
What are causes of ischemic stroke?
Embolic - afib, endocarditis, emboli through PFO, valvular disease
Nonembolic - from cerebral vascular anomaly
What are the etiologies of hemorrhagic stroke?
vascular anomalies
AVMs
What is the acute management of stroke?
- CT head without contrast, FAST RECOGNITION (<20min)
- POCT glucose, keep blood glucose 140-180
- Airway, Sat >94%
- Treat hyperthermia (high temp accelerates damage)
What is the management of ischemic stroke?
If CT says no hemorrhagic component:
- tPA administration (0.9 mg/kg based on pre-pregnancy weight) w/in 4-5 hours
- Tx blood pressure <160/110
- consider thrombectomy (even if s/p tPA)
What is secondary prevention after a stroke?
Aspirin
Lovenox
(start 24 hours after tpa administration)
Does tPA cross the placenta?
No
What are the risks of tPA in pregnancy
placental abruption
What are the main contraindications to tpa?
- Uncontrolled HTN despite anti-htnsives
- high risk of hemorrhagic conversion (hx of intracranial hemorrhage, head trauma, GI bleeding, on anticoag, plt <100K, INR >1.7)
- Infective endocarditis
- Resolving stroke sx (TIA)
- Intracranial neoplasm
What is the work-up for cause of ischemic stroke?
- EKG
- Echo
- CTA or MRA
- DVT (if PFO found)
- thrombophilia w/u
How do you care for someone who is s/p stroke in pregnancy?
ASA in current and future pregnancy
Consider ppx anticoagulation
What is the target BP for hemorrhagic stroke?
<140/90
Venous sinus thrombosis - presentation and associations
Presents with severe, refractory headache. Associated with seizures.
Presents 3rd T or PP
How do you diagnose venous sinus thrombosis?
CT or MR venography
Seen in superior sagital and transverse sinuses
How do you treat venous sinus thrombosis?
Therapeutic anticoagulation
PPX Lovenox in future pregnancy (recurrent 1%)
Carotid or basilar dissection - associations
Associated with cervical trauma / manipulation; pre-eclampsia
Treatment of carotid or basilar dissection
antiplatelet or therapeutic anticoagulation
Reversible cerebral vasoconstriction syndrome
Narrowing of intracranial arteries seen postpartum
Precipitated by drug use (amphetamines), also preE, triptans, anti-depressants, immunosuppressants, occ HTN
Tx is symptomatic
Nitabuch layer
Nitabuch layer is the zone of fibrinoid degeneration that interferes with invading trophoblasts from penetrating the decidua basalis. Missing (partially or incompletely) in an accreta
What are the manifestations of Parvovirus in pregnancy?
Hydrops due to fetal anemia
8-17% risk of pregnancy lss <20 wks, 2-6% risk of loss >20 weeks
What dopplers peak systolic velocity is concerning for anemia?
> 1.5 MOM
What is the risk of vertical transmission of toxoplasmosis?
20-50% without maternal treatment
How do you treat maternal toxoplasmosis?
Maternal infection - spiramycin
Fetal infection - sulfadiazine and pyrimetamine, folinic acid
What are effects of toxoplasmosis on the fetus?
chorioretinitis, rash, ventriculomegaly
What are the pregnancy complications of varicella zoster?
maternal - pneumonia (10-20%), mortality (40%)
fetal - limb hypoplasia, microcephaly, cardiac anomaly
high rate of neonatal death with exposure 5 days prior to delivery
What are findings on ultrasound concerning for CMV?
echogenic bowel
ventriculomegaly
periventricular calcifications
hydrops
FGR
Echogenic bowel is found on ultrasound. What should you test for?
CMV
CF
How is Parvovirus infection diagnosed in mom? In fetus?
Mom - serum IgG/IgM
Fetus - amnio PCR
When is the highest risk of congenital / transplacental CMV?
third trimester; increases with gestational age
What is NAIT?
Maternal alloimmunization to fetal platelets
How does NAIT present?
Petechiae
Bleeding after circumcision
seizures s/p intracranial hemorrhage
How is NAIT managed?
weekly IVIg, sometimes prednisone
What is the most common platelet antigen associated with NAIT?
HPA-1a
Mom is antigen negative
fetus is antigen positive
Which organisms are most commonly associated with obstetric sepsis?
E coli
Klebsiella pneumonia
Proteus
(aerobic, GNR)
Candidates for an ultrasound-indicated cerclage?
Preterm delivery <34w
CL <25mm
Women with chronic HCV are at risk for what in pregngancy?
cholestasis
What are the risks of a neural tube defect in someone with 0, 1 and 2 affected siblings?
0.04% baseline risk
3.2% risk with 1 sibling
10% risk with 2 siblings
Which neural tube defect is associated with polyhydramnios?
Anencephaly - impairs fetal swallowing
What percent of pregnancies have thrombocytopenia?
7-12%
How low are platelets usually in gestational thrombocytopenia?
> 70K
How far apart do APLA labs need to be?
12 weeks apart
APLA criteria
- arterial or venous thrombosis
- pregnancy loss x3 before 10wk
- pregnancy loss x1 >10wk
- preterm delivery <34w 2/2 preE or placental insufficiency
When should someone wtith a wide aortic root (eg Marfans) be delivered by c-section?
aortic root 40-45mm
decrease risk of aortic rupture
prophylactic aortic surgery is recommended before pregnancy if possible for >45mm
What are fetal consequences of untreated hyperthyroidism?
SAB
fetal tachycardia > hydrops
IUFD
When is scheduled cesarean section recommended for HIV?
> 1000 copies
at 38 weeks
How do you define oligo/poly in twins?
MVP ONLY
<2 or >8
Neural tube defects are associated with what genetic mutation in parents?
MTHFR
When would you re-date based on CRL vs LMP?
before 9 weeks: discrepancy >5 days
9-16 weeks: >7 days
16-22w: >10 days
22-28w: >14 days
28+ w: >21 days
What is the recommended dose of Vit D in pregnancy for Vit D deficiency?
1000 IU (normal prenatal has 400 IU)
What is the recommended dose of folic acid supplementation in low risk and high risk women?
Low risk: 400mcg
High risk: 4mg
Supplement until 12 weeks gestation
Loveset maneuver
Flex the fetal elbow and sweep the arm to remove nuchal arm in breech delivery
Mariceau maneuver
Flex the fetal head by placing fingers on the fetal maxilla during breech delivery
Pinard maneuver
Delivering legs in breech position
Feel fetal thigh, flex at knee, move away from midline, then pull foot down into vagina
What are the fetal risks of a pregnant mom with phenylalanine hydroxylase deficiency (phenyllketonuria)?
Dev delay 92%
Microcephaly 73%
Congenital heart defect 12%
If not diet controlled
What is the most common platelet antigen associated with NAIT?
HPA-1a
Maternal treatment for varicella
if >5 days before delivery: oral acyclovir
if <5 days before delivery: oral acyclovir, neonate gets VZIg
Neonatal varicella within 2 weeks of life: IV acyclovir
Antibiotic preferred for toxoplasmosis in pregnancy
Spiramycin. Concentrates in the placenta.
SMFM definition of periviable
20w0d to 25w6d
Fetal blood volume at term
78 mL/kg (fetus alone)
125 mL/kg (fetus and placenta)
Risks of radiation during organogenesis
Congenital anomalies (skeleton, eyes, genitals)
Risks of radiation during 8-15w gestation
intellectual disability (high risk)
microcephaly
risks of radiation during 16-25w
severe intellectual disability
Most likely way to acquire toxoplasmosis
Undercooked pork and lamb products
What is the rhogam dose for CVS?
<12 weeks: 50-120mcg
>12 weeks: 125-300mcg
What can give you false POSITIVE nitrazine?
BV
Blood
Semen
Soap
Cervical mucous
When do you re-date a pregnancy?
At less than 9 weeks: >5 day discrepancy
At 9-14 weeks: >7 day discrepancy
At 15-16wks: >7 day discrepancy
at 16-22wks: >10 day discrepancy
At 22-28wks: >14 day discrepancy
At >28 weeks: >21 day discrepancy
What data supports regional anesthesia for ECV?
Neuraxial PLUS tocolytic = higher incidence of success
No evidence for neuraxial without tocolysis
How do you interpret a CST?
Negative: no decels
Positive: lates after 50% or more of ctx
Equivocal: intermittent late or significant variable
Hyperstim: decels with tachysystole or ctx lasting >90sec
Unsatisfactory: <3 ctx in 10 minutes
What are the benefits of IOL in PROM?
Lower rates of chorio and endometritis
Lower rates of NICU admission
Quicker time to delivery
