Placenta accreta spectrum — structured oral station (12 minutes)

Opening prompt — "Tell me what this report means."

Model response — interpret, then quantify, then commit: [2][4]

• "This report describes placenta accreta spectrum with features suggesting percreta. She has four of the standardised descriptors: multiple lacunae with turbulent flow, loss of the clear zone, myometrial thinning under 1 mm, and uterovesical hypervascularity with bridging vessels."
• "The finding that worries me most is the interrupted bladder wall interface. In the multicentre imaging analysis, bladder wall interruption was the only ultrasound descriptor that independently predicted percreta, with an odds ratio of 3.23."[4]
• "With praevia and three previous caesareans, her risk of accreta from the MFMU cohort is about 40%, and this scan pushes her well above that. I would treat her as having accreta spectrum with possible bladder involvement — FIGO grade 3b if confirmed at surgery."[2][3]

Examiner is listening for: named signs rather than "the scan looks bad", a risk figure, and a stated working diagnosis with a grade. [3][4]

Probe 1 — "Would you order an MRI? Justify it."

• "I would consider MRI, but for topography, not for exclusion. Ultrasound and MRI have comparable overall accuracy, so MRI does not confirm or exclude the diagnosis — it maps the depth and extent, particularly parametrial and bladder involvement, which changes who I want scrubbed."[1][4]
• "I would be explicit that a normal MRI would not reassure me here. The ultrasound findings already commit me to a full accreta pathway."[4]

Probe 2 — "Who needs to be involved, and where should she deliver?"

• Name the team, not the concept: "senior obstetrician experienced in accreta surgery, obstetric anaesthetist, urologist, interventional radiologist, haematologist and the transfusion service, neonatologist, theatre coordinator and intensive care."[5][6]
• "She needs to deliver in a centre with a blood bank able to deliver a massive transfusion, urology, interventional radiology and an intensive care bed. If she lives remotely I would arrange relocation with accommodation and support for her family, because being in the right building on the right day is the treatment."[5][1]
• Quote the evidence: "In the Shamshirsaz cohort the multidisciplinary group had more percreta yet lost less blood and were far less likely to be delivered as an emergency. The pathway itself is the intervention."[5]

Probe 3 — "When will you deliver her, and why not wait for term?"

• "A scheduled caesarean at 34 to 36 weeks, with corticosteroids timed to that date and a neonatal cot booked. The Robinson and Grobman decision analysis found 34 weeks gave the highest quality-adjusted life years, and amniocentesis to confirm lung maturity did not improve outcomes at any gestational age."[10]
• "I am trading a small, well-understood prematurity cost against a large, poorly controlled haemorrhage cost. Waiting for term means accepting a growing chance of an unplanned night-time operation, which is the exposure that kills."[10][5]

Probe 4 — "Walk me through the operation."

• "Midline or generous transverse laparotomy. Inspect the serosa and map the upper placental edge before I touch the uterus."[6]
• "Hysterotomy remote from the placenta — fundal or classical here, because the placenta fills the lower anterior segment. Deliver the baby, clamp the cord short, and leave the placenta completely undisturbed."[6]
• "Close the hysterotomy, then hysterectomy with the placenta in situ. Total, not subtotal, because the bleeding lower segment and cervix have to come out in praevia."[6][1]
• "Ureters identified early. If the bladder is involved, urology does the dissection, with cystoscopy and stents considered preoperatively and planned partial cystectomy rather than blunt separation."[6][4]
• "Alongside: tranexamic acid, cell salvage, warmed products, a quantitative loss tally, and a stated escalation plan."[1][5]

Examiner will interrupt with: "What if you cannot find a plane at the bladder?" Correct answer: stop the blunt dissection, get urology, consider leaving a cuff of bladder or performing a partial cystectomy, and accept a longer operation rather than an avulsed bladder. [6][4]

Probe 5 — "Your colleague wants prophylactic internal iliac balloon catheters. What do you say?"

• "I would say the randomised evidence does not support routine use. In Salim's trial of 27 women, balloon catheters made no difference to red cell units transfused, 5.2 versus 4.1, to calculated blood loss, 4950 versus 4709 mL, or to hysterectomy rate, 46.2% versus 50.0% — with reversible catheter-related adverse effects in 15.4%."[7]
• "I would still discuss interventional radiology availability for resuscitative aortic occlusion or for postoperative embolisation, and I would not obstruct a colleague who uses them well. What I would not do is present them as standard of care or let them delay the case."[7][6]

Probe 6 — "Who should be operating: you, or a gynaecological oncologist?"

• "Either, provided they do this operation regularly. The Monash 20-year Australian cohort of 88 women showed that when experienced obstetricians took over as primary surgeon, maternal outcomes were comparable to the era when gynaecological oncologists led, and hysterectomy rates actually fell from 100% to 73.3% with no significant change in blood loss."[8]
• "The variable that matters is case volume and a rehearsed team, not the badge on the surgeon."[8][5]

Probe 7 — communication. "She is in front of you. She has three children and wants one more. Talk to her."

This is a scored domain. Demonstrate it out loud, at her pace. [1][9]

• Sit down, use her name, check what she already understands, and ask permission to explain what the scan shows.
• "The scan suggests the placenta has grown into the scar from your previous caesareans, and possibly into the bladder wall. That means it will not come away on its own after the baby is born."
• "The safest operation we know is to deliver the baby through an incision away from the placenta, then remove the womb with the placenta still inside it. Trying to peel it away is what causes life-threatening bleeding."
• Name the loss explicitly and then stop talking. "That would mean you could not carry another pregnancy. I am sorry — I know that is a very hard thing to hear."
• Offer the alternative honestly: "There is an approach where we leave the placenta and keep the womb. In the largest series, about 78 women in 100 kept their uterus, but about 6 in 100 had a serious complication such as infection, injury or kidney failure, and about 11 in 100 still needed the womb removed later. It also means months of follow-up. I can go through whether that is a reasonable option for you with our team."[9]
• Close with a plan: written information, a named contact, a second appointment with her partner if she wants one, and a clear statement that the final decision is made with her.[1][9]

Probe 8 — "What if you meet this unexpectedly at a district hospital?"

• "Stop. No traction, no attempt at removal. Call the most senior obstetrician and anaesthetist available, alert blood bank, and ask for a second surgeon."[6]
• "If the baby is out, the placenta is undisturbed and she is stable, closing the uterus and abdomen with the placenta in situ and transferring to a resourced centre is a defensible plan. If she is already bleeding, I run the massive haemorrhage protocol and get surgical control where I am, with aortic compression as a temporiser while help arrives."[6][1]