Changes During Reopening in Premature Constriction or Closure of the Ductus Arteriosus: A Report of Two Cases.

Although premature constriction or closure of the ductus arteriosus (PCDA) is associated with poor prognosis and early delivery is considered before deterioration occurs, some cases may improve and have a good prognosis, but the changes in fetal Doppler during the reopening of the ductus arteriosus are unclear, as are the factors related to its reopening. We encountered two cases of PCDA. In the first case, right cardiac function and ductus venosus flow normalized in a few days and the ductus arteriosus reopened spontaneously, and became vaginal delivery at 37 weeks of gestation. In the second case, labor induction was performed due to confirmed fetal cardiac stress associated with the closure of the ductus arteriosus at 38 weeks of gestation, and cesarean section was performed due to non-reassuring fetal status. The improvement in the right ventricular myocardial performance index, ductus venosus pulsatility index, the tendency for ductus arteriosus diastolic velocity to decrease, and confirmation of prograde flow into the pulmonary artery within a few days could serve as predictive indicators for the reopening of the ductus arteriosus.