Introduction: Patent ductus arteriosus (PDA) is a commonly encountered morbidity that occurs inversely with gestational age. In response to the growing trend of avoiding PDA ligation and prophylactic interventions, our center adopted a conservative approach starting in September 2020. This approach involves more precise fluid restriction for hemodynamically significant (hs) PDA. This study aimed to evaluate whether a conservative approach to hsPDA has led to a reduction in adverse clinical outcomes for very low birth weight infants (VLBWIs) during the period of conservative treatment. Methods: Since more conservative approach to hsPDA was adopted since September 2020, the two periods were divided into period 1 (January 2015 to August 2020) and period 2 (September 2020 to June 2023). Fluid therapy was carefully monitored and advanced from day 1 in all VLBWI, and a more conservative approach as fluid restriction was attempted in hsPDA during period 2. Results: Of the 540 VLBWI with hsPDA, 348 infants were born and diagnosed with hsPDA. Period 2 demonstrated a significantly higher rate of medical treatment (79.17% vs. 19.51%) and lower PDA ligation (54.17% vs. 78.05%). Period 2 showed a greater adherence to conservative fluid restriction compared to period 1. Bronchopulmonary dysplasia (BPD) and BPD ≥ moderate, sepsis, necrotizing enterocolitis (≥ grade 2), IVH (grade ≥3) were notably lower in period 2 with lower mortality. In regard to PDA-related treatment, primary PDA ligation was significantly higher in period 1. The secondary PDA ligation after medical failure and more conservative fluid restriction were significantly higher in period 2. At corrected age of 18–24 months, cognitive score was significantly lower in VLBWI born in period 1 compared to those born in period 2. Conclusion: Our study demonstrated that a conservative approach to hsPDA led to better clinical outcomes and improved cognitive scores at a corrected age of 18–24 months compared to the period of active PDA ligation. This conservative strategy, involving more precise fluid restriction and the judicious use of appropriate diuretics, has shown to improve clinical outcomes with minimal intervention.