Periviability counselling at 23+4 weeks — structured SAQ (15 marks)

(a) ANZNN 2023 survival for under-24-week infants and the four exclusions (3 marks)

One mark for the number from source, two marks for the four exclusions. ^[1]

• ANZNN 2023 Table 29 reports survival to discharge home of 50.7% for babies born under 24 weeks (71 of 140 babies). Reproduced verbatim from the source.
• The four exclusions that push the ANZNN percentage up: fetal deaths, neonatal deaths on the labour ward, babies born in level II hospitals, and babies never transferred to an NICU or children's hospital.
• Therefore the honest number for this fetus in utero is lower than 50.7% until she is born, admitted to a NICU and survives transfer. State the denominator before you quote the percentage.^[1]

(b) The four obstetric levers (4 marks)

One mark per lever, with action stated. ^[2][3][5][1]

• Antenatal corticosteroids. Give the first dose now — before transfer, not after. The Cochrane review (Roberts 2017) shows benefit for perinatal death, neonatal death, respiratory distress syndrome and intraventricular haemorrhage. A partial course still confers benefit.
• Magnesium sulphate for fetal neuroprotection. Start now if your unit's protocol permits at 23+4 weeks; the Crowther 2017 individual participant data meta-analysis shows a reduction in cerebral palsy when birth is anticipated before 30 weeks.
• In-utero transfer to the level III centre. Treat as a therapeutic intervention. Outborn extremely preterm neonates have higher mortality and morbidity than inborn (Fang 2020).
• The unit's active treatment policy. Know whether the receiving level III centre offers active resuscitation at 23+4 weeks; Rysavy 2015 showed this explains much of the between-hospital variation in outcome at the threshold. State it honestly to the parents.^[2][3][5][1]

(c) The counselling script and the pitfalls to avoid (4 marks)

One mark per element. ^[1][6]

• Ask what the parents want to know first. Some want every number; some want only to know if their baby will live. Ask before you deliver statistics.
• Use natural frequencies, not percentages. "Of ten babies like yours at this gestation, about half go home" beats "50.7 per cent" — and it carries the uncertainty honestly.
• State the range, the denominator and what you can change. "That figure is survival of babies admitted to a tertiary nursery. Your baby is still inside you, so the honest number is lower. The four things I am doing now — steroids, magnesium, transfer, agreeing with the neonatal team what we will do at birth — each move the number."
• Pitfalls to avoid: the denominator pitfall (quoting a NICU figure to a woman in labour), the vintage pitfall (data from a decade ago), the false-precision pitfall (a percentage to two decimal places), the construct pitfall (letting "moderate-to-severe impairment" sound catastrophic when it includes language delay alone), the steering pitfall (language that makes a genuine choice sound like the only reasonable option), and the discordance pitfall (obstetrics and neonatology quoting different numbers — agree the script first).^[1][6]

(d) MAGENTA and the magnesium recommendation (2 marks)

One mark for the trial name and one for the finding. ^[4]

• MAGENTA (Crowther, JAMA 2023) randomised women at 30 to 34 weeks at risk of preterm delivery to prenatal intravenous magnesium sulphate vs placebo. It did not significantly reduce death or cerebral palsy in offspring.
• The magnesium benefit is at earlier gestations (typically before 30 weeks in ANZ practice); extending routine use to 34 weeks is not supported by MAGENTA. The Crowther 2017 IPD meta-analysis supports the earlier-gestation recommendation.^[4]

(e) In-utero transfer principle and the evidence (2 marks)

One mark for the principle, one for the evidence. ^[5]

• Principle: in-utero transfer to a level III centre is the single largest modifiable determinant of outcome for a woman presenting in preterm labour to a non-tertiary hospital — treat it as a therapeutic intervention, pursued in parallel with steroids and magnesium, not instead of them.
• Evidence: Fang (Arch Dis Child Fetal Neonatal Ed 2020) reports higher mortality and morbidity in outborn extremely preterm neonates admitted to a NICU with respiratory distress than in inborn infants. Outcomes at the threshold are partly a function of where the baby is born.^[5]