Levo-Transposition of the great arteries accompanying defect(s). If a right-to-left or bidirectional shunt is present, the list of symptoms may include mild cyanosis. In a normal heart, oxygen-depleted ("deoxygenated") blood is pumped from the right atrium into the right ventricle, then through the pulmonary artery to the lungs where it is oxygenated. The oxygen-rich ("oxygenated") blood then returns, via the pulmonary veins, to the left atrium from which it is pumped into the left ventricle, then through the aorta to the rest of the body, including the heart muscle itself. With l-TGA, deoxygenated blood is pumped from the right atrium into the morphological left ventricle
Single umbilical artery Single umbilical artery Occasionally, there is only the one single umbilical artery (SUA) present in the umbilical cord. Approximately this affects between 1 in 100 and 1 in 500 pregnancies, making it the most common umbilical abnormality. It is more common in multiple births. Its cause is not known. Most cords have one vein and two arteries. The vein carries oxygenated blood from the placenta to the baby and the arteries carry deoxygenated blood from the baby to the placenta. In approximately 1% of pregnancies there are only two vessels —usually a single vein and single artery. In about 75%