To evaluate the evidence from randomised controlled trials that routine screening for congenital heart disease by echocardiography (versus no routine echocardiography) reduces morbidity and mortality in neonates with Down syndrome.

Sub-group analyses:
1. Trials where routine echocardiography was planned within the first week of post-natal life and trials where routine echocardiography was scheduled for any point during the neonatal period.
2. Trials in which the participating infants had clinical examination alone and trials in which the infants had clinical examination plus electrocardiography and/or radiography and/or oxygen saturation monitoring.
3. Trials in which the participating infants had antenatal ultrasound screening for congenital heart disease and trials in which the infants did not have antenatal ultrasound screening for congenital heart disease.