Introduction: Intra-uterine dysfunction of the duct occurs; incidence and clinical consequences are poorly understood.
Patients and methods: Retrospective analysis of fetal (n=602) and neonatal echocardiographic databases (n = 1477) between 1998 and 2008. Clinical and imaging studies were reviewed for pathology due to or associated with premature closure of the duct.
Results: Twelve cases were identified. Eight (1.3%) were diagnosed prenatally at 29.0 weeks (range: 20.0–37.5 w). Four neonates (0.3%): all presented with significant cyanosis and absence of duct. Echo: RV hypertrophy (n=12), more than usual tricuspid regurgitation (n=12) and pulmonary regurgitation (n=11), and right atrial dilation (n=8); pulmonary artery dilation in 42% , dysplastic pulmonary valve in 25%, hydrops 8%. Premature delivery was advised for 5 patients. Neonatal therapy: observation and oxygen 7, ventilation with pulmonary vasodilators 5, ECMO in 1. Respiratory failure with severe pulmonary hypertension was the cause of death in 3. During follow-up two children required additional right heart procedures, 1 developed non-compaction cardiomyopathy at 4 years.
Conclusion: The incidence of ductal dysfunction may be grossly underestimated. Fetal premature closure of the arterial duct causes stress at different fetal ages and many different levels of the right heart and pulmonary circulation, resulting in a wide range of secondary pathology. Clinical outcomes range from antenatal hydrops and right heart damage to lethal respiratory insufficiency. Premature delivery may be indicated in selected patients.