Morbidly adherent placenta

Question 1

Define placental adhesive spectrum

Answer 1

Placental invasion into muscle layer of uterus
a) Placenta accreta: Superficial invasion onto uterine muscle ( May separate at birth)
b) Placenta increta: Deep invasion into uterine muscle, up to serosal layer ( Will not separate at birth)
c)Percreta: Invasion of placenta through uterine muscle and uterine serosa into surrounding organs.

Question 2

Best imaging modality for Diagnosis

Answer 2

Ultrasound by qualified, experienced specialist has comparable accuracy, wide availability and cost effectivity as opposed to MRI

MRI may be useful in determination of depth of invasion or pelvic extension for surgical planning. Useful for posterior placenta where US evaluation is difficult

Question 3

Who should manage PAS

Answer 3

MDT:
- Specialist obstetrician supervising delivery
- Specialist Anaesthetist supervising anaesthetic during delivery
- Specialist experienced with diagnosis of PAS
- specialist experienced with complicated surgery: Gynae- Oncologist and Urologist

Question 4

Important components of MDT plan for management

Answer 4

-On site transfusion service/critical bleeding protocol available, including haematological expertise
available.
* Discussion and consent, including possible interventions (such as hysterectomy, leaving the
placenta in situ, cell salvage and interventional radiology).
* Local availability of adult and neonatal intensive care (or special care 32+ weeks nursery)

Question 5

Options for surgical management of PAS

Answer 5

1.Uterus conserving procedures (e.g., placenta left in situ or partial myometrial resection) may be considered
as an alternative to planned caesarean hysterectomy for appropriately counselled women who are willing
to follow advice regarding the need for close surveillance. Services caring for women having uterus
conserving procedures must have the capacity to manage potential complications including the need for
emergency hysterectomy and emergency massive transfusion.

The SDP recommends where placental separation has occurred spontaneously, Bakri balloons or B-Lynch sutures may be appropriate as surgical adjuncts to achieve haemostasis, however, manual removal of the placenta in women with PAS is associated with severe haemorrhage and should not be employed solely to
allow for the use of uterine tamponade techniques.

The routine use of interventional radiology techniques (embolisation or placement of arterial segment
balloon designed to arrest arterial blood flow to the gravid uterus) is not recommended for women with
PAS at the time of birth.
more likely to have arterial embolization compared to women having caesarean
hysterectomy (24.4% vs 3%).
Observational study in France
- Conservative management was found to have lower associated risk of needing
transfusion > four units of red blood cells (RBCs)
- Lower rate of hysterectomy
- Lower rates of blood loss exceeding 3000mL
- Lower rates of adjacent organ
injury and non-PPH related severe maternal morbidity.
- No maternal deaths occurred in the study period.
- No perinatal outcomes were reported.
- Women with conservative management had a higher associated risk of endometritis and readmission within six months.

Different EU Obs study:
-n Unplanned hysterectomy was associated with increased risk of blood loss >3500mL compared to planned hysterectomy.
- Little to no difference was found in blood loss between partial myometrial resection and planned hysterectomy.
- Whilst blood loss >3500mL was less common in women who had successful conservative management (placenta left in situ)
- in women who required delayed hysterectomy risk of blood loss >3500mL was more likely than planned
hysterectomy.
- Manual removal of placenta was associated with a reduction in blood loss and massive blood loss (>3500mL), however manual removal of placenta was attempted significantly less frequently in this group and only performed in lower PAS grades of invasion.

2. Planned Caesarean Hysterectomy

• Delivery of baby through incision away from placenta

Nil RCT comparing methods

Question 6

Risk factors for PAS

Answer 6

1. Increased maternal age
2. prior caesarean section
3. placenta praevia diagnosed prior
   to birth
4. multiple birth

Question 7

Incidence of PAS

Answer 7

44.2/100 000 (Aus and NZ) (1:2000)
60.2/100 000 in NZ
38.8/100 000 in Aus

Question 8

Features of PAS on ultrasound:

Answer 8

Low sensitivity but high specificity
1. Placental Lacunae sensitivity 77% (71%-83%) specificity 95% (94%-96%);
2. loss of retroplacental clear space sensitivity 66% (58%-74%), specificity 96% (95%-97%)
3. bladder border abnormalities sensitivity 50% (41%-58%), specificity 100% (99%-100%)
4. colour doppler abnormalities
sensitivity 91% (85%-95%), specificity 88% (85%-90%).

Question 9

Pre op requirements

Answer 9

1. Planning for delivery: including PA protocol
   - optimise HB
   - appropriate setting including surgical team: urologists, interventional radiology, specialist anaesthetist, Gynae Oncologist and experienced OB
   - MTP/MBT protocol in place
   - patient consented for hysterectomy and transfusion if required

Question 10

Timing of delivery

Answer 10

1. Uncomplicated: RCOG recommends 35+0 to 36+6

Question 11

Appropriate anaesthetic

Answer 11

Women should be informed that regional anaesthetic is appropriate and safe with a risk of conversion to GA in case of complications. NB anaesthetic team involvement in discussion