Preterm labour and birth — structured SAQ (15 marks)

(a) Immediate priorities in the first 30 minutes (5 marks)

One mark per point with its justification, maximum five. ^[1][2]

• Confirm the diagnosis and the gestation. A cervical length of 14 mm with a fibronectin of 320 ng/mL in a symptomatic woman puts her in the highest-risk band; check the dating scan, not the chart heading.^[9]
• Actively exclude the diagnoses that forbid delay — chorioamnionitis (fever, tachycardia, tenderness, offensive liquor), significant abruption (constant pain, tense tender uterus, bleeding) and non-reassuring fetal status. Here all three are absent, which is what permits tocolysis.^[1][2]
• Give the first dose of antenatal corticosteroid now. Do not wait for the consultant, the scan or the retrieval service; the benefit is time-dependent and the commonest failure is a dose that was planned and never given.^[1]
• Start magnesium sulfate for fetal neuroprotection because birth within 24 hours is plausible at 28+4 weeks.^[4][5]
• Escalate the place of birth. Ring the tertiary unit and the retrieval service, and involve the neonatal team before the birth. Baseline bloods (FBC, CRP), MSU, high vaginal swab and group B streptococcus status are taken in the same 30 minutes.^[8][2]

Reasoning marks are awarded for naming what each action is for — for example "tocolysis is only to buy the 48 hours for the steroid course and the transfer". ^[6]

(b) The two drugs that improve this baby's outcome (4 marks)

Two marks per prescription: one for the agent and dose, one for route, interval and duration. Marks are lost for "corticosteroids and magnesium" without numbers. ^[1][4]

Add the monitoring in the same breath: hourly respiratory rate, deep tendon reflexes, conscious state and urine output while magnesium runs, and calcium gluconate 1 g intravenously over 10 minutes available as the antidote.^[4][2]

(c) Tocolysis — agent, regimen, purpose, contraindications (4 marks)

One mark for the agent with a correct dose and regimen, one for stating the purpose, two for four absolute contraindications. ^[6][7]

• Agent: nifedipine immediate-release, commonly 20 mg orally, repeated once after 30 minutes if contractions continue (maximum 40 mg in the first hour), then 20 mg every 6 to 8 hours for up to 48 hours. Atosiban is the accepted alternative: 6.75 mg intravenous bolus over 1 minute, then 18 mg per hour for 3 hours, then 6 mg per hour for up to 45 hours.^[6][7]
• Purpose: 48 hours, and only 48 hours — to complete the corticosteroid course, deliver magnesium sulfate, and achieve in-utero transfer. Tocolysis on its own does not improve neonatal outcome.^[6]
• Four absolute contraindications (any four): chorioamnionitis; significant placental abruption; non-reassuring fetal status; advanced established labour; intrauterine fetal death; lethal fetal anomaly with a plan for birth; severe preeclampsia or eclampsia; any maternal condition requiring delivery.^[1][2]
• Say why you did not choose a betamimetic: it is the class most likely to force treatment cessation for maternal adverse effects, with pulmonary oedema and tachyarrhythmia as the feared complications.^[6]

(d) In-utero transfer (2 marks)

• Justify it in one sentence: at 28+4 weeks this baby needs a level of neonatal intensive care this hospital cannot provide, and the uterus is a better transport incubator than any retrieval cot — the Victorian extreme prematurity data show that a guideline promoting in-utero transfer changed both place of birth and survival at the earliest gestations.^[8]
• Two circumstances to keep her and deliver locally: advanced labour where birth is likely before or during transfer; maternal instability (haemorrhage, sepsis, eclampsia) making transfer unsafe; a retrieval time longer than the anticipated time to birth. In any of these, deliver in place and call the neonatal retrieval team to come to you.^[8][2]