Final answer:
Central cyanosis in newborns is usually caused by shunting of blood from right to left due to a congenital heart defect like Tetralogy of Fallot, leading to insufficiently oxygenated blood and the 'blue baby' syndrome. This condition often requires surgical repair for correction.
Step-by-step explanation:
Central Cyanosis in Newborns and Congenital Heart Defects
Central cyanosis, characterized by a blue or purple coloration of the skin, is an indication that there is an insufficient supply of oxygenated blood in a newborn. This condition is usually caused by congenital heart defects that result in shunting of blood from right to left. One such defect is the Tetralogy of Fallot, which consists of four components, one of them being the right-to-left shunt through a ventricular septal defect. This allows deoxygenated blood to bypass the pulmonary system where it would normally become oxygenated, thus leading to central cyanosis.
Once the newborn begins to breathe, normal cardiac reconfiguration occurs and the fetal shunts close, Neonatal Circulatory System. If a congenital defect like the Tetralogy of Fallot exists, the normal closure and reconfiguration do not occur properly, leading to the condition known as a "blue baby". Treatment for these conditions typically involves surgical repair to correct the abnormalities and improve oxygenation.