Placenta accreta spectrum — structured SAQ (15 marks)

(a) Further assessment and the findings you are looking for (4 marks)

One mark each, maximum four. Marks for naming the modality AND the specific finding. ^[1][3]

• Specialist repeat ultrasound with colour Doppler, transabdominal and transvaginal, by an operator experienced in placenta accreta spectrum. Looking for the standardised descriptors: loss of the clear zone, placental lacunae, myometrial thinning, bladder wall interruption, placental bulge, uterovesical hypervascularity and bridging vessels. Ultrasound in at-risk women has a sensitivity of about 90.7% and specificity of about 96.9%.^[3][1]
• MRI as an adjunct for topography, not for exclusion — depth of invasion, parametrial and bladder extension, and posterior involvement. Sensitivity about 94.4% and specificity about 84.0%, with no significant accuracy advantage over ultrasound, so a normal MRI does not exclude percreta.^[4]
• Specifically document bladder involvement. In the multicentre imaging analysis, bladder wall interruption was the only ultrasound descriptor that independently predicted percreta (odds ratio 3.23, 95% CI 1.33–7.79).^[5]
• Haematological and transfusion work-up: full blood count and iron studies with active correction of anaemia, group and antibody screen, coagulation screen, and confirmation that crossmatched units and cell salvage will be available on the day.^[1][6]

A mark is also available for stating that antenatal imaging raises suspicion but the diagnosis is confirmed clinically at birth and by histopathology, graded with the FIGO clinical classification. ^[1]

(b) Antenatal plan to the day of birth (4 marks)

One mark each, maximum four. ^[6][7]

• Refer to the multidisciplinary placenta accreta spectrum team and name it: senior obstetrician experienced in PAS surgery, obstetric anaesthetist, urologist, interventional radiologist, haematologist and transfusion service, neonatologist, theatre and intensive care. A standardised multidisciplinary approach reduced blood loss and emergency delivery even though the team's cases were more severe.^[6]
• Confirm care in a resourced centre with a blood bank able to deliver a massive transfusion, interventional radiology, urology and an intensive care bed. Arrange antenatal relocation if she lives remotely.^[1][6]
• Plan a scheduled caesarean at 34 to 36 weeks, with antenatal corticosteroids timed to that date and a neonatal cot booked. The decision analysis favours 34 weeks, and amniocentesis for lung maturity does not improve outcomes at any gestation. Bring the date forward for bleeding.^[7][1]
• Consent and counselling documented in detail: likely caesarean hysterectomy with permanent loss of fertility, massive transfusion, bladder or ureteric injury, relaparotomy, intensive care admission, and a late-preterm baby who may need neonatal care. Include a plan for antepartum bleeding, with admission and an escalation trigger, and give her written information.^[1][8]

(c) Operative steps of planned caesarean hysterectomy, with reasons (4 marks)

Half a mark per step and half a mark per reason, maximum four. "Caesarean hysterectomy" without the sequence scores poorly. ^[8][1]

Also creditable: tranexamic acid, cell salvage, warmed products, a running quantitative loss tally, and a stated decision point for escalation. ^[1][6]

(d) Counselling on uterine preservation (3 marks)

One mark per element, maximum three. Full marks need numbers, not reassurance. ^[9][10]

• What conservative management is: the placenta is deliberately left in situ, partially or completely, with no attempt at forcible removal, and the uterus retained. It is offered only in centres with the resources and follow-up to support it.^[9]
• The figures to quote: in the largest multicentre series of 167 women, the uterus was preserved in 78.4% (95% CI 71.4–84.4), primary hysterectomy was needed in 10.8% and delayed hysterectomy in a further 10.8%, and severe maternal morbidity occurred in 6.0% — sepsis, fistula, injury to adjacent organs, renal failure and thromboembolism. Spontaneous placental resorption occurred in 75% at a median of 13.5 weeks, so follow-up runs for months.^[9]
• The honest caveats: one woman in that series died from intraumbilical methotrexate toxicity, so adjuvant methotrexate is not recommended; delayed interval hysterectomy is an option in expert centres with lower blood loss in selected patients but carries its own interval risk; and recurrence in a subsequent pregnancy is real, so she should be counselled about contraception and about high-risk care next time.^[9][10]

A mark is lost for promising uterine preservation, and for offering conservative management without naming the morbidity or the length of follow-up. ^[9]