placenta previa

Question 1

what is normal nomenclature

Answer 1

any placenta abutting or overlying os = placenta previa

any placenta near but not overlying os = low lying placenta

Question 2

what % of placenta previas seen on 2nd trimester US will resolve?

Answer 2

80-90%. Therefore repeat US at 32 weeks

Question 3

delivery planning

Answer 3

> 2 cm away from internal os = vaginal delivery
1-2 cm but not previa = uncertain best delivery plan
overlying os = c-section

Question 4

delivery timing?

Answer 4

in stable cases: 36w0d to 37w6d

if vaginal bleeding considering earlier ANC < 34 weeks with L&D admission

Question 5

describe 2 types of vasa previa?

Answer 5

• type I: velamentous cord insertion

- type II: bilobed/succincurate placenta

Question 6

fetal survival rate if diagnosis is made intrapartum vs antepartum?

Answer 6

44% vs 97%

Question 7

what % will resolve in 3rd trimester?

Answer 7

20%

Question 8

risk factors for vasa previa

Answer 8

• velamentous cord insertion
• bilobed/succincurate placenta
• IVF
• multiple gestations
• previa or low lying placenta

Question 9

antepartum management/delivery of vasa previa?

Answer 9

• consider inpatient admission from 30-34 weeks; although outpt is reasonable if consider : hx PTB, cervical length, symptoms, time to get to hospital
• ANC: 28-32 weeks
• timing: 34-37 weeks, cesarean delivery (typical is 35 weeks)