A case of progressive ductal constriction in a fetus.

The ductus arteriosus is a normal and essential structure in fetal circulation. Since the introduction of fetal echocardiography, there have been reports of ductal constriction, many of which were related to maternal use of some medications. However, there have been some reports of idiopathic ductal constriction, which usually present in later gestation. Recently we experienced a case, which initially showed an S-shaped ductus with mild narrowing at 23 weeks and 27 weeks gestation and developed severe ductal constriction at 33 weeks. Soon after birth, ductus was searched for but no ductus was found in 2-D and color images. The neonate required mechanical ventilation with supplemental oxygen for 3 days. All echocardiographic abnormalities were normalized in 7 months. We report progressive ductal constriction in an S-shaped ductus and emphasize the importance of continuous follow up extending to the third trimester and even immediately after birth.