Human ductus arteriosus. A histological study on the relation between ductal maturation and gestational age.

The present study deals mainly with the ductus arteriosus of preterm infants of gestational age less than 29 weeks, birth weight less than 1200 g, and postnatal age less than 72 hours. Excised ductus were histologically examined postmortem and compared to those of infants of more advanced gestational age. Intimal cushion and duplication and/or interruption of the internal elastic lamina of the ductus arteriosus were employed as the indicators of the maturation of the ductus arteriosus. The ductus arteriosus of infants with gestational age more than 29 weeks showed histologically more mature features than those of 28 weeks or less. It is considered that there is a relation between gestational age and histologic maturation of the ductus arteriosus.