Placental Abnormalities

Question 1

Risk of accreta with 5th C/S? 6th?

Answer 1

5th - 2%

6th - 7%

Question 2

Risk of hysterectomy with 4th, 5th, 6th C/S?

Answer 2

4th - 2.5%
5th - 3.5%
6th - 9.0%

Question 3

How does placenta accreta occur?

Answer 3

When trophoblastic villi burrow into an area of poorly developed or absent decidua

Question 4

In setting of anterior placenta previa, risk of accreta with number of prior C/S

Answer 4

1st - 3%
2nd - 11%
3rd - 40%
4th - 60%
5th or more - 70%

Question 5

Sonographic features of placenta accreta

Answer 5

1. Irregularly shaped placental lacunae with turbulent internal flow by Doppler
2. Thinning of myometrium overlying the placenta
3. Loss of the retroplacental hypoechoic “clear” zone
4. Absence of a decidual interface with nl placental echogenicity
5. Interruption or increased vascularity of the uterine serosa-posterior bladder wall interface
6. Apparent bulging or protrusion of the placenta into the bladder

Question 6

Most predictive sonographic sign of accreta

Answer 6

Presence of placental lacunae - 80% sensitivity in 15-20w range, 93% in 15-40w range