Placenta Praevia, Accreta and Vasa Praevia GT27

Question 1

What constitutes Type 1 and 2 Vasa Praeva and what is the incidence?

Answer 1

Type 1 - 2dry to velamentous cord insertion in single/bilobed placenta

Type 2 - between lobes of placenta with one or more accessory lobe

1 in 2000-6000 pregnancies
1 in 300 IVF

Question 2

What is the perinatal mortality rate with vasa praevia?

Answer 2

60% (97% if diagnosed antenatally)

Question 3

What are the risk factors for placenta praevia?

Answer 3

Placental anomalies
LLP in T2
Twins and higher order
IVF

Question 4

When should placentae be re-scanned in pregnancy?

Answer 4

Asymptomatic minor praevia 36/40

Major PP or ?accreta; previous CS with PP/anterior placenta over scar 32/40

Question 5

When would CS be likely in placenta praevia?

Answer 5

If edge is <2cm from internal os in T3 - consider TVUS if engaged prior to CS

Question 6

At what gestation should CS be performed for abnormal placentation?

Answer 6

Not before 38/40 for praevia

36-37/40 with steroid cover for accreta

Question 7

What is the follow up if placenta accreta is retained?

Answer 7

• Warn risk of bleeding/infection
• Prophylactic abx
• USS and serum b-HCG once weekly (but doesn’t guarantee resolution)
• UAE and methotrexate does not reduce risk
• No date re: progonisis/future pregnancy

Question 8

What is the management of vasa praevia?

Answer 8

• Cat 1 CS if presents with bleeding, in labour
• If confirmed at term elCS 35-37/40
• If identified T2 repeat imaging T3
• If confirmed - admit 28-32/40 with steroid cover

Question 9

What is the strongest predisposing risk factor for placenta praevia?

Answer 9

Maternal age >40 - x9