Paracetamol Treatment of the Borderline Significant PDA

In the neonatal intensive care unit of the Shaare Zedek Medical Center, preterm babies \<30 wks. GA, are studied echocardiographically on day of life 3-4. Pending parental informed consent, those diagnosed with a PDA of borderline significance will be randomized to receive either paracetamol or placebo for three days, followed by a repeat echocardiogram. If the PDA remains of borderline significance, the treatment will be continued for an additional 4 days (1 week total). Paracetamol levels and liver functions will be assessed after the third day. Babies will be followed until discharge for subsequent PDA pathology; respiratory distress and chronic lung disease \[CLD\]; necrotizing enterocolitis \[NEC\]; retinopathy of prematurity \[ROP\]. The investigators' primary goal is to demonstrate a decrease in the composite outcome of death or severe morbidity chronic lung disease \[CLD\], as shown by decreased time on supplemental oxygen and assisted ventilation. Secondary goals: * To demonstrate a decrease in subsequently diagnosed hs PDA, including * Decrease in the need for subsequent therapy for PDA closure * Decrease in surgical PDA ligations * To demonstrate a decrease in necrotizing enterocolitis (NEC) and/or ROP with treatment. * To demonstrate no adverse effect on blood flow in anterior cerebral, superior mesenteric and renal arteries.