The circulatory system of an unborn infant, or fetus, functions quite differently from that of a baby after birth. While a baby after birth gets life-giving oxygen from its lungs, a fetus receives oxygen from its mother through the placenta. As shown in the prenatal diagram of a baby's heart at left, oxygenated blood travels from the placenta to the fetus's heart by way of the umbilical vein. The fetal circulation heart structure has a couple of features that differ from the normal postnatal heart. First, there is an opening in the atrial septum called the foramen ovale (FO in diagram). This allows most of the blood that enters the right atrium to flow into the left atrium instead of into the right ventricle. Second, there is a connection between the pulmonary artery and aorta called a ductus arteriosus (DA in diagram). This vessel allows blood to flow from the pulmonary artery into the aorta. These features both close soon after birth with the dramatic change in the heart's circulatory pattern. |
Scientific Software Solutions, Inc.
makers of: & Software for Congenital Heart Disease |