Prior studies showed that, if a moderate/large Patent Ductus Arteriosus (PDA) is still present at 5 days after birth (among infants delivered at 23 and 0/7 to 25 and 6/7 weeks gestation) or at 7 days after birth (among infants delivered at 26 and 0/7 to 27 and 6/7 weeks gestation), it will persist for at least another 4-12 weeks if it is left untreated.
