Preterm prelabour rupture of membranes — structured oral station (12 minutes)

Opening prompt — "How do you assess her?"

Model response: [1][4]

• "I would take a focused history: the exact time of rupture, the colour and volume, fetal movements, any fever or feeling unwell, her group B streptococcus status, and any recent infection or intercourse."
• "I would examine her: temperature, pulse, blood pressure, abdominal palpation for tenderness and presentation, and a sterile speculum looking for pooling in the posterior fornix, cervical appearance and dilatation, and any visible cord."
• "I would not perform a digital vaginal examination. She is not in labour, it shortens latency, it increases infection, and the speculum has already told me what I need."
• "At the same speculum I would take a high vaginal swab and a group B streptococcus sample, and send FBC, CRP and an MSU."[1]

Examiner is listening for: the speculum named first, the digital examination declined out loud with a reason, and swabs taken at the same time. [1]

Probe 1 — "The speculum shows no obvious pooling but she is adamant. What now?"

• "I would keep her recumbent for a few minutes and repeat the inspection, because a high or hindwater leak may not pool immediately."[1]
• "If it is still equivocal I would use a biochemical test — IGFBP-1 or PAMG-1 on a vaginal swab — and be aware both can be falsely positive with blood, semen or infection."[1]
• "I would also look at the liquor volume on ultrasound. Reduced liquor supports the diagnosis, but a normal amniotic fluid index does not exclude it, so I would arrange review rather than discharge her with 'no PPROM' written in the notes."[1]

Probe 2 — "Rupture is confirmed at 26 weeks. What do you prescribe, and what will you not prescribe?"

• "Erythromycin 250 mg orally four times daily for 10 days, or until labour — the ORACLE I regimen. It improved the neonatal composite in singletons, prolonged pregnancy and reduced surfactant use, oxygen dependence and major cerebral abnormality on ultrasound before discharge."[2]
• "I would not prescribe co-amoxiclav. In ORACLE I it increased neonatal necrotising enterocolitis, and the Cochrane pooled risk ratio is 4.72."[2][3]
• "Antenatal corticosteroids — betamethasone 11.4 mg intramuscularly, two doses 24 hours apart. Ruptured membranes are not a contraindication, and the Cochrane review found no significant increase in chorioamnionitis or endometritis."[5]
• "Magnesium sulfate 4 g intravenously over 20 to 30 minutes then 1 g per hour if birth becomes likely within 24 hours at this gestation, with calcium gluconate available as the antidote."[6]
• If asked about tocolysis: "I would not routinely tocolyse. In the Cochrane review, tocolysis in PPROM prolonged latency by about 73 hours but increased a 5-minute Apgar under 7 and the need for ventilation, with more chorioamnionitis below 34 weeks and no mortality benefit."[8]

Probe 3 — "What is your surveillance plan, and what exactly are you watching for?"

• "Temperature and pulse at least 4-hourly, daily assessment of uterine tenderness and of liquor colour and smell, fetal movement awareness, CTG at a frequency set by gestation, and fortnightly growth scans. Inflammatory markers as a trend."[1]
• "I am watching for suspected Triple I: a documented fever without a clear source, plus any of a baseline fetal tachycardia over 160 bpm for 10 minutes or longer, a maternal white cell count over 15 000 per cubic millimetre in the absence of corticosteroids, or definite purulent fluid from the cervical os."[4]
• "The trap is the corticosteroid. It raises the white cell count for about three days, so I would not read a high count in that window as infection, and I would never read a normal count as safety."[4][5]
• "I would also reassess venous thromboembolism risk weekly if she stays in, and I would consider whether she could be managed at home. A French cohort of 587 women found no significant difference in the perinatal composite between inpatient and outpatient policies, but that requires selection, education, a thermometer, written escalation triggers and proximity to hospital."[9]

Probe 4 — "She reaches 34 weeks with no infection. Do you deliver?"

• "Not automatically. PPROMT randomised 1839 women at 34+0 to 36+6 weeks: neonatal sepsis was 2% with immediate birth and 3% with expectant management, so delivering did not prevent sepsis, while immediate birth increased respiratory distress from 5% to 8% and increased mechanical ventilation and intensive care stay."[7]
• "So I would continue expectant management with surveillance, and plan birth at around 37 weeks unless infection, abruption, fetal compromise or labour intervenes. I would put that trade-off to her explicitly and document the discussion, because guidelines differ: RCOG supports waiting to about 37 weeks while ACOG supports birth from 34 weeks."[7][1]
• "Her group B streptococcus status would shift my threshold, and so would any concern about growth or liquor."[1]

Probe 5 — "She is crying. She says she cannot stay in hospital for eleven weeks — she has two children at home."

This is a scored domain. Demonstrate it out loud. [1]

• Sit down, eye level, no notes in your hand: "That is a completely reasonable thing to say. Eleven weeks away from your children is a huge ask, and I want us to find a plan that is safe for the baby and liveable for you."
• Explain the trade-off in her words: "Every week we can safely keep the baby inside makes a real difference to how well the baby does. But we watch closely, because if an infection starts, the safest thing becomes having the baby."
• Offer the options honestly: "Some women in your situation can be looked after at home once things are stable, with a thermometer, clear instructions and a short trip back here. It depends on how far away you live and how things go this week — let me talk to my consultant and come back to you with a proper plan."[9]
• Involve social work, arrange family accommodation if she must stay, and commit to a named review time. Do not promise home care you cannot deliver.[9][1]