Antenatally diagnosed fetal conditions: paediatric planning — formative SAQs

SAQ 1 — Hypoplastic left heart syndrome at the antenatal counselling visit (20 marks, ~15 minutes)

A 34-year-old woman at 22 weeks gestation has a fetal echocardiogram confirming hypoplastic left heart syndrome with a normal karyotype and no other anomalies. She lives three hours from the nearest cardiac centre and asks what will happen when the baby is born. She is anxious and asks whether the baby will need surgery. [1] [19]

Questions

1. Explain why hypoplastic left heart syndrome is described as a ductal-dependent circulation and why this drives the place of delivery. (4 marks) [1]
2. Outline the neonatal resuscitation plan that must be in place from the moment of birth, including the role of prostaglandin E1. (5 marks) [1] [19]
3. Describe the staged surgical strategy and the role of the medical home in long-term follow-up. (5 marks) [1] [20]
4. Give four elements of non-directive counselling you would use at this visit, given the distance from the cardiac centre. (3 marks) [2]
5. Describe three system actions that ensure the written neonatal plan is not lost given the rural geography. (3 marks) [2]

Model answer anchors

1. Hypoplastic left heart syndrome depends on the ductus arteriosus to carry blood from the pulmonary artery to the systemic circulation; when the duct closes in the first hours of life the systemic circulation collapses. Antenatal diagnosis exists so delivery is planned at a cardiac-capable centre with prostaglandin ready, because the same lesion delivered unprepared presents as cardiovascular collapse. [1]
2. Warmth; commence a prostaglandin E1 infusion; avoid hypoxia and hyperoxia by titrating oxygen to the saturation target; pre-ductal and post-ductal saturation monitoring; echocardiogram to confirm the lesion and guide the strategy; deliver where cardiac capability and an intensive care team are present from the first breath. [1] [19]
3. The staged strategy is typically Norwood (or hybrid in selected centres), followed by Glenn and Fontan procedures across infancy and early childhood. The medical home coordinates neurodevelopmental surveillance, interstage monitoring, feeding and growth, and the family's contact with the cardiac service, because survivors carry real neurodevelopmental morbidity. [1] [20]
4. State plainly what is known and what is uncertain; describe the staged strategy in plain terms; offer written information and a named contact; use teach-back; respect the family's values and time; acknowledge the distance and plan around real travel. [2]
5. A written neonatal alert shared with the cardiac centre and the referring site; a named owner with contact details and a backup; transport and accommodation planning; interpreter if needed; a chase list so the booking is not silently lost. [2]

SAQ 2 — Congenital diaphragmatic hernia and the resuscitation plan (20 marks, ~15 minutes)

A 29-year-old woman at 24 weeks gestation has a confirmed left congenital diaphragmatic hernia with bowel in the chest and mediastinal shift; karyotype is normal. She is booked at a tertiary centre and asks what will happen at birth and whether the baby will need an operation straight away. [7] [8]

Questions

1. Explain the two mechanisms by which congenital diaphragmatic hernia causes neonatal respiratory failure. (4 marks) [7] [8]
2. Outline the immediate resuscitation plan at birth, including a specific technique to avoid. (5 marks) [7]
3. Describe the timing and rationale for surgical repair relative to stabilisation. (3 marks) [7]
4. Explain the role of antenatal diagnosis and standardised postnatal protocols in changing survival. (4 marks) [7] [8]
5. Give four elements of the long-term follow-up plan coordinated by the paediatric medical home. (4 marks) [20]

Model answer anchors

1. The herniated bowel compresses the developing lung, producing pulmonary hypoplasia (too few and too small airways and vessels), and the same vascular abnormality drives persistent pulmonary hypertension of the newborn with right-to-left shunting and hypoxaemia. The two mechanisms operate together. [7] [8]
2. Avoid mask ventilation, which inflates the intrathoracic stomach-bowel and worsens compression; intubate early; place a gastric tube for decompression; ventilate gently to limit barotrauma and pulmonary hypertension; deliver at a tertiary NICU that can manage pulmonary hypertension and provide echocardiography. [7]
3. Surgical repair is delayed until the infant is stabilised and pulmonary hypertension is manageable; operating as an emergency on an unstable, hypoxaemic infant worsens outcomes. Standardised protocols frame this stabilisation-first approach. [7]
4. Antenatal diagnosis allows delivery at a tertiary centre with the right capability from the first breath; standardised postnatal CDH protocols (ventilation, pulmonary-hypertension management, timing of repair) have been shown to improve survival compared with unstructured care. [7] [8]
5. Respiratory and pulmonary-hypertension follow-up; growth and feeding surveillance; neurodevelopmental monitoring; coordination of surgical and cardiology reviews; hearing screening where relevant; a named owner and safety-net. [20]