The effects may range from a slight change in blood pressure to an interruption in circulation depending on the nature and degree of the misplacement, and on which specific vessels are involved.

In this same condition, the left heart continuously pumps oxygenated blood back into the lungs through the pulmonary artery, instead of out into the body's circulation as it normally would.

Complications can arise from the pressure change due to the fact that the right ventricle, which is adapted for pumping blood into the low-pressure pulmonary circulation, is being tasked with pumping blood at a much higher pressure against the high resistance of the systemic circulation, since it is now in the position of where the left ventricle is typically located.

Most babies with TGA have blue skin color (cyanosis) in the first hours or days of their lives, since dextro-TGA is the more common type.

[citation needed] Before surgery: For newborns with transposition, prostaglandins can be given to keep the ductus arteriosus open which allows for the mixing of the otherwise isolated pulmonary and systemic circuits.

[5] Atrial septostomy can also be performed, usually with a cardiac catheter instead of surgery, to enlarge a natural connection between the heart's upper chambers (atria).

This will allow for the oxygen-rich and oxygen-poor blood to mix, resulting in improved oxygen delivery to the baby's body.