Deformities of the heart and adjacent blood vessels which are present at birth. They are usually discovered shortly after birth if they cause serious symptoms, but problems may not occur for years, and sometimes not at all. About 7 babies in every 1,000 have a congenital heart disorder, and of these half do not survive the first month because the severity of the condition precludes treatment. Congenital heart conditions occur through constructional faults in the first months of pregnancy; they can be caused by some infectious diseases such as German measles in the mother, but in most cases no cause can be found. Cyanosis can point to a congenital heart disorder, as can poor growth, shortness of breath and heart murmurs. Specialist examination is necessary to determine the nature of the condition and whether or not surgery is necessary and possible. Holes in the heart (atrial and ventricular septal defect) are the commonest congenital heart abnormalities (40 per cent). Patent ductus arteriosus is abnormal persistence after birth of the connection between pulmonary artery and aorta (about 13 per cent); stenosis (narrowing) of the valve of the pulmonary artery makes up 10 per cent, and the same figure applies to Fallot’s tetralogy, a serious condition involving a combination of four heart abnormalities.