Preterm prelabour rupture of membranes — structured SAQ (15 marks)

(a) Confirming the diagnosis, and the examination to avoid (3 marks)

One mark for the speculum, one for what you look for and collect, one for naming and justifying the avoided examination. [1]

• Sterile speculum examination is the reference standard: leave her recumbent for a few minutes, then look for pooling of liquor in the posterior fornix, assess cervical appearance and dilatation visually, and exclude a visible cord or fetal part.[1]
• Collect at the same time: high vaginal swab and group B streptococcus sample, since her status is unknown.[1]
• If pooling is equivocal: IGFBP-1 (Actim PROM) or PAMG-1 (AmniSure) on a vaginal swab; both can be falsely positive with blood, semen or infection, so they supplement rather than replace the speculum. Ultrasound showing reduced liquor supports the diagnosis but a normal volume does not exclude it.[1]
• Avoid the digital vaginal examination unless she is in established labour or birth is imminent. It shortens latency and increases the risk of intrauterine infection while adding nothing the speculum has not already provided.[1]

(b) Latency antibiotics and the drug to avoid (4 marks)

Two marks for the correct prescription with drug, dose, route, frequency and duration; one for naming co-amoxiclav; one for naming necrotising enterocolitis. [2][3]

Add the benefit in one line if you have time: latency antibiotics reduce chorioamnionitis (risk ratio 0.66), birth within 48 hours (risk ratio 0.71) and neonatal infection (risk ratio 0.67), without reducing perinatal mortality. If erythromycin is not tolerated, azithromycin gives similar latency with less clinical chorioamnionitis in pooled data.[3][8]

(c) Expectant management for the next two weeks (4 marks)

One mark each for the drug package, the maternal surveillance, the fetal surveillance, and clearly stated escalation triggers. [1][5]

• Drugs: complete the erythromycin course; give a course of antenatal corticosteroids (betamethasone 11.4 mg intramuscularly, two doses 24 hours apart, or dexamethasone 6 mg intramuscularly, four doses 12 hours apart) — ruptured membranes are not a contraindication. Have magnesium sulfate 4 g intravenously over 20 to 30 minutes then 1 g per hour ready if birth becomes imminent within the local gestational threshold.[5][6]
• Maternal surveillance: temperature and pulse at least 4-hourly, daily assessment of uterine tenderness and of liquor colour and smell, and FBC and CRP as a trend rather than a single value — remembering that corticosteroids raise the white cell count for about three days.[1][4]
• Fetal surveillance: CTG at a frequency set by gestation and local policy, daily fetal movement awareness, and growth scans every 2 weeks with liquor volume.[1]
• Escalation triggers — say them explicitly: maternal fever, maternal or fetal tachycardia, uterine tenderness, offensive liquor, rising inflammatory markers, vaginal bleeding with pain, reduced fetal movements, or contractions. Any of these means reassessment for birth. Also arrange in-utero transfer to a unit with the neonatal level this gestation needs, and reassess venous thromboembolism risk weekly during prolonged admission.[1][9]
• Plan the endpoint: in the absence of infection, plan birth at around 37 weeks, and discuss the trade-off from 34 weeks — PPROMT showed immediate birth at 34 to 36+6 weeks did not reduce neonatal sepsis but did increase respiratory distress and ventilation.[7]

(d) Day 9 deterioration — classify and act (4 marks)

One mark for correctly classifying, one for explaining the corticosteroid caveat, two for the management. [4]

• Classification: suspected Triple I (intrauterine inflammation or infection or both). She has a documented fever without a clear source plus a baseline fetal tachycardia over 160 bpm sustained for 10 minutes or longer.[4]
• The corticosteroid caveat: the white cell criterion (over 15 000 per cubic millimetre) is only valid in the absence of corticosteroids. She had betamethasone on day 1, so the raised count on day 9 is beyond the usual 3-day corticosteroid effect but should still be read as one strand of evidence, not the diagnosis. The fever plus fetal tachycardia is what makes this suspected Triple I.[4][5]
• Management: deliver. Start broad-spectrum intravenous antibiotics per local protocol, inform the neonatal team, continue continuous fetal monitoring, and expedite birth by the safest route. PPROM and chorioamnionitis are not in themselves indications for caesarean — the route follows obstetric factors.[4][1]
• Complete the package: magnesium sulfate for neuroprotection if the gestation is within the local threshold and birth is expected within 24 hours, taking care not to delay the birth for it; send the placenta for histopathology; and debrief the woman afterwards.[6][4]