Definitions of congenital heart defect (CHD)
| Non-significant | Presence of any one of the following at birth no longer detected at 6 months: small PDA; small PFO/ASD); muscular VSD; mildly abnormal turbulence at branch pulmonary artery |
| Significant | Above defects persisting for longer than 6 months of age. Also any cardiac lesion which requires regular monitoring beyond 6 months or requiring drug treatment but not categorised as serious or critical |
| Serious | Any defect not defined as critical which requires intervention or results in death between 1 month and 1 year of age |
| Critical | All infants with hypoplastic left heart, pulmonary atresia with intact ventricular septum, simple transposition of the great arteries or interruption of the aortic arch. All infants dying or requiring intervention within the first 28 days of life with the following conditions: coarctation of the aorta; aortic valve stenosis; pulmonary valve stenosis; tetralogy of Fallot; pulmonary atresia with ventricular septal defect; total anomalous pulmonary venous connection |
| Non-significant and significant CHD are classified as minor CHD and serious and critical as major CHD. | |
ASD; atrial septal defect; PDA; patent ductus arteriosus; PFO; patent foramen ovale; VSD; ventricular septal defect.