Aim-To investigate the relation between gestational age, birth weight, and antenatal corticosteroid administration and the time of ductus venosus closure. Methods-Ninety eight neonates of 30-41 weeks gestational age were studied by daily ultrasonography until ductus venosus closure. Results-In neonates of 30-33 weeks gestational age, the ductus venosus closed at 6.0 (2.4)days (mean (SD)); in those of 34-36 weeks gestational age, it closed at 6.1 (2.8) days; and in those of 37-41 weeks gestational age, it closed at 4.2 (2.1) days. The eVect of antenatal administration of corticosteroids on the time of closure was also investigated in neonates of 30-34 weeks gestational age. Closure occurred by 5.5 (2.4) days in the group given corticosteroids compared with 7.5 (2.1) days in the remainder. Conclusions-The ductus venosus closed sooner after birth in neonates of greater gestational age or higher birth weight. Antenatal corticosteroid administration had a significant eVect in promoting closure. (Arch Dis Child Fetal Neonatal Ed 2001;85:F57-F59) Keywords: ductus venosus closure; antenatal corticosteroids; gestational age; birth weightThe adaptation of the respiratory, circulatory, endocrine, metabolic, and nervous systems from the intrauterine to the extrauterine environment must be accomplished dynamically and smoothly at birth. The adaptation of the postnatal circulatory system is the most abrupt and dynamic of these changes. There are three specific vascular shunts in the fetal period: the foramen ovale, which by closing separates the left and right heart systems; the ductus arteriosus, which separates the pulmonary and systemic circulation; the ductus venosus, which separates the hepatoportal and systemic circulation. The pathophysiology and mechanism of closure and the pharmacological manipulation of the ductus arteriosus have been studied in detail. The ductus venosus, on the other hand, has been the subject of very little study because it is regarded as having little pathophysiological significance. A functionally patent ductus venosus was found to shunt at least 25% of the total portal blood flow in 50% of lambs between the second and sixth days of life, 1 which is a level that cannot be ignored. Moreover, the early postnatal period is an unstable phase for the respiratory and circulatory systems and often a period of frequent drug treatment. In addition, if feeding is started from an early age, liver metabolism and other factors aVect ductus venosus patency, and clinically there is the possibility of deleterious eVects on the body from endogenous and exogenous toxic substances.The purpose of this study was to investigate the relation of gestational age and birth weight to the time of functional closure of the ductus venosus, as well as whether or not antenatal administration of corticosteroids aVects the time of closure.
Materials and methodsThe subjects were 98 neonates of 30-41 weeks gestational age, who were in the Perinatal Center of the Ehime Prefecture Central Hospital between June 1995 and D...