The incidence of congenital heart disease is the rate of new cases of congenital heart disease, usually expressed as the number of babies born with congenital heart disease per 1,000 live births.

Data from the Northern Region Paediatric Cardiology Database show that between 1985 and 1999 there were 5.2 cases of congenital heart disease diagnosed in infancy for every 1,000 live births.

However, not all cases of congenital heart disease are diagnosed in infancy. Incidence rates based on diagnoses in the first 12 months of life will, therefore, be an underestimate of the true incidence.

Further data from the Northern Region Paediatric Cardiology Database suggest around 1 in 4 cases of congenital heart disease in the UK are diagnosed later in childhood. Based on these figures, we estimate the incidence rate for congenital heart disease in the UK to be 6.9/1,000, or one in every 145 babies born¹.

From this incidence rate we estimate that there are just over 4,600 babies born with congenital heart disease in the UK each year.

The Glasgow Register of Congenital Anomalies is a population-based registry covering all births within the Greater Glasgow Health Board in Scotland. All cases of congenital anomaly identified in live births, stillbirths and induced abortions following prenatal diagnosis are recorded in the register, along with a classification of the main type of anomaly. Between 1980 and 1997, the overall incidence of congenital heart defects in the Glasgow Register fell by around 25% from 8.3/1,000 to 6.2/1,000 live and still births².

1. Data from the USA suggest that at least 10% of cases seen in a GUCH clinic are not diagnosed until adulthood - in particular secundum atrial septal defect, Ebstein’s anomaly and congenitally corrected transposition. (Webb G and Williams R (2001) 32nd Bethesda Conference: Care of the Adult with Congenital Heart Disease. Journal of the American College of Cardiology; 37: 1161-98). Assuming this is also the case in the UK, the true incidence rate of congenital heart disease  is a further 10% higher, around 7.6/1,000 (or 1 in 132 births, around 5,000 babies born in the UK per year).

2. The Glasgow Registry excludes heart defects not requiring surgery (for example, mild ventricular septal defects) and defects occurring in babies born at less than 37 weeks, or weighing less than 2,500g. This means that incidence rates for congenital heart disease reported by the Glasgow Register are lower than those reported by the Northern Region paediatric cardiology database, which is likely to be a truer reflection of the underlying incidence.