The fetus does not depend on its lungs to deliver oxygen to the growing organism in the uterus; it derives its oxygen and nutrition through the mother's placenta. Before birth, a blood vessel called the ductus arteriosis (DA) allows blood to circumvent the nonfunctional fetal lungs by connecting the pulmonary artery (that transports blood to the lungs) with the aorta that sends blood throughout the body. This is a temporary measure and, normally, this vessel closes a day or two following birth so that the lungs may begin normal function. If this vessel does not close, there is abnormal blood circulation between the heart and lungs. The resulting condition is called patent ductus arteriosis (PDA). Infants with this condition exhibit certain characteristic symptoms including, fast breathing, poor eating habits, shortness of breath, poor growth and heart murmur.
PDA is often found in premature infants and those individuals born with neonatal respiratory distress syndrome as well as babies with congenital disorders such as Down's syndrome and mothers who contracted German measles during pregnancy.
Studying newborn mice, Doctor Katrin Echtler and his colleagues from Munich discovered that circulating platelets (specialized cells that play an essential role in blood clotting) were involved in the normal closing of the DA, and that if platelet production was disrupted, the DA failed to close completely. Their findings were reported in the Journal of Natural Medicine. This could prove to be an important finding with possible direct application to infants susceptible to PDA.