Placenta accreta/previa/vasa previa

Question 1

What is placenta accreta spectrum

Answer 1

Morbidly adherent placentation
- Accreta = onto myometrium (grade 1)
- Increta = into myometrium (2)
- Percreta = into uterine serosa or surrounding viscera (3, a -serosa, b-bladder, c-surrounding organs)

Question 2

Risk factors?

Answer 2

Previa after prior CS (3% if one, 67% if fifth or greater) if previa
But <1% overall up until 6th or greater CS
Any other uterine surgery

Question 3

Symptoms

Answer 3

Profuse bleeding on placental separation
Bleeding with a previa
Haematuria

Question 4

Signs on USS

Answer 4

Ideally TV+TA USS 18-24 weeks in women with anterior previa and previous surgery
Placental lacunae
Disruption of the bladder/uterine serosa interface
Loss of ‘clear’ zone
Myometrial thinning
Abnormal vascularity
Colour flow doppler bridging vessels
Exophytic mass
1st trimester USS suggestive of CS scar ectopic
MRI can be useful

Question 5

Treatment options

Answer 5

Tertiary centre
MDT
Early delivery - steroids
- Stable = 34-35+6
- Unstable = individualise
Anti-D
G+H, optimise Hb, cell saver, TXA
Consider - delivery of baby and uteirne closure then hysterectomy, attempted placental delivery, conservative management - leave placenta insitu (1/3 still need hysterectomy in future)
Consider ureteral stents
Consider GA
Positioning - lithotomy

Question 6

Recurrence risk for accreta spectrum

Answer 6

25%

Question 7

Timing of delivery for previa?

Answer 7

Any life threatening bleeding
Significant bleeding >34 weeks
Generally for asymptomatic complete previa at 38 weeks
LLP asymptomatic can be delivered at 39 weeks

Question 8

RF for previa

Answer 8

Previous previa - 4-8% recurrence
Previous CS
Multiple gestation
Previous uterine surgery
Increasing parity
IVF
Smoking
Cocaine use
Male fetus
Prior UAE
Endometriosis
Previous abortion

Question 9

Associated findings with a previa?

Answer 9

IUGR, malpresentation, vasa previa, velamentous cord, congenital anomalies