Placental abruption — structured SAQ (15 marks)

(a) Working diagnosis and why the visible loss misleads (4 marks)

One mark for the diagnosis, two for the supporting features, one for the concealed-haemorrhage explanation. ^[1][2]

• Working diagnosis: placental abruption with fetal compromise, largely concealed.^[1]
• Supporting features: pain preceding the bleeding; dark rather than bright loss; a woody hard, tender uterus that does not relax; a symphysis-fundal height that has risen 4 cm in two weeks; a shock index of 124 divided by 128, which is 0.97 and abnormal, especially against a booking blood pressure of 146/92 mmHg; and a pathological CTG.^[1][7]
• Risk factors present: smoking and a hypertensive booking blood pressure, both established independent risk factors.^[8]
• Why the visible loss misleads: in abruption, blood is trapped behind the placenta and forced between the myometrial fibres, so external loss may be minimal while a large volume accumulates internally. Roughly one in five abruptions is concealed, and this group presents in shock with a near-clean pad.^[1][2]
• A mark is available for stating that a normal ultrasound would not exclude the diagnosis because sonographic sensitivity is low.^[3]

(b) Immediate management, first ten minutes (4 marks)

One mark each for calling and declaring, resuscitation with specifics, the coagulation set, and the decision to deliver with the correct category and anaesthetic implication. ^[1][5]

• Call and declare: consultant obstetrician, anaesthetist, midwifery coordinator, blood bank, neonatal team for a 33-week birth; activate the massive obstetric haemorrhage protocol.^[1]
• Resuscitate: left lateral tilt, two large-bore cannulae, warmed crystalloid then blood, catheter with hourly urine output, active warming, and a quantitative running loss total with the fundal height marked and timed.^[5]
• Bloods on the first draw: full blood count, coagulation profile with fibrinogen, group and antibody screen, crossmatch four units, U&E and liver function, and a Kleihauer if she is RhD negative. Repeat the coagulation set every 30 to 60 minutes.^[4][5]
• Deliver: a pathological CTG with a clinically suspected abruption means category 1 caesarean section. Warn the anaesthetist that coagulopathy is likely, so general anaesthesia rather than neuraxial blockade.^[2][5]
• Adjuncts that do not delay birth: betamethasone 11.4 mg IM if there is time; magnesium sulphate for neuroprotection is not indicated at 33+4 weeks under the Australian and New Zealand under-30-weeks threshold.^[1]

(c) Interpreting the results and haemostatic management (4 marks)

One mark for interpreting fibrinogen against the pregnancy range, one for naming disseminated intravascular coagulation, one for the products, one for the numerical targets. ^[4][5]

• Fibrinogen 1.3 g/L is severely low. Pregnancy raises fibrinogen to roughly 4 to 6 g/L at term, so this is a profound fall and an early fibrinogen decrease is a validated predictor of severe haemorrhage.^[4]
• This is consumptive coagulopathy — obstetric disseminated intravascular coagulation driven by decidual and placental tissue factor entering the maternal circulation, with fibrinogen falling first and fastest.^[5]
• Products: cryoprecipitate or fibrinogen concentrate immediately, red cells, fresh frozen plasma per the massive haemorrhage protocol, platelets, and calcium replacement, all warmed.^[5][4]
• Targets: fibrinogen at or above 2 g/L, platelets above 50 x 10 to the ninth per litre, normal ionised calcium, normothermia, and haemoglobin maintained per local transfusion policy.^[5][4]
• Do not wait for the prothrombin time and APTT — they move later than fibrinogen, so a normal clotting screen is falsely reassuring. Viscoelastic testing, where available, gives a faster answer.^[5]

(d) The uterus at caesarean (3 marks)

One mark for the diagnosis, one for stating it usually contracts, one for the explicit statement that it is not by itself an indication for hysterectomy. ^[6][1]

• Diagnosis: Couvelaire uterus (uteroplacental apoplexy) — blood forced between the myometrial bundles discolours the serosa.^[6]
• Management: give uterotonics as per protocol, assess uterine tone directly, and expect most Couvelaire uteri to contract. Continue transfusion and correct the coagulopathy in parallel.^[6][5]
• It is not by itself an indication for hysterectomy. Retrospective data associate it with greater blood loss, more transfusion and more coagulopathy, so it warrants preparation and vigilance — but the decision to remove the uterus is made on uncontrollable bleeding after the full haemostatic ladder has failed, not on the colour of the serosa.^[6][1]
• Anticipate postpartum haemorrhage: prophylactic uterotonics, tranexamic acid, and a balloon and compression sutures available before you close.^[1][5]