The three options for the treatment of patent ductus arterioles (PDA) in preterm infants are conservative approach, pharmacological intervention and surgical ligation. There is not any randomized-controlled trial that demonstrates the superiority of these approaches in preterm infants.

Patent ductus arteriosus (PDA), of which incidence is inversely related to gestational age and birth weight, is one of the the most common conditions among preterm infants.

In recent years, the use of antenatal steroids, postnatal surfactant, noninvasive ventilation strategies and low oxygen saturation targets have affected the incidence of hemodynamically significant PDA (HSPDA). There is not any consensus about the best approach on the clinical management of PDA in preterm infants. Over past years, the management of HSPDA shifted to aggressive medical and surgical intervention from conservative treatment, but conservative treatment approach has been mainly concerned again nowadays.

Today, the three options for the treatment of PDA in preterm infants are conservative approach, pharmacological intervention and surgical ligation. There is not any randomized-controlled trial that demonstrates the superiority of these approaches in preterm infants. Many countries including developed countries only give recommendations, instead of publishing guidelines, on screening, timing of treatment and treatment choices of PDA, because of the differences on management of PDA between the centers even within a single center.

Timing of PDA treatment and treatment choices at preterm infants born before 28 gestation weeks' differ in our country also in many countries over the world. In this study, it is aimed to record the managements of PDA detected beyond postnatal 3 days, to compare the effects of the managements at postnatal 3-7 days and after 7 days on closure, surgical ligation rates and side effects of drugs.

Inclusion Criteria:

• Infants born at 24 0/7-28 6/7 gestation weeks'
• PDA detected with ductal diameter equal or greater than 1.5 mm and LA/Ao equal or greater than 1.5 on echocardiography at or after postnatal 72 hours of life

Exclusion Criteria:

• Infants died before 72 hours of life
• Infants detected PDA but treated before 72 hours of life

Infants born at 24 0/7-28 6/7 gestation weeks' who were performed echocardiography at or after postnatal 72 hours of life, and detected ductal diameter equal or greater than 1.5 mm and LA/Ao equal or greater than 1.5 are the candidates for the study. The management of PDA and the other data of these infants will be registered to online registry system.

No data individual data will be shared