This study evaluates the usefulness of liver perfusion and oxygenation status using regional oxygen saturation (RSO2) values obtained via near-infrared spectroscopy in assessing the hemodynamical significance of patent ductus arteriosus in preterm infants.

The usefulness of cerebral and renal regional oxygen saturation (RSO2) values for assessing hemodynamically significant patent ductus arteriosus (hsPDA) has been described previously. Meanwhile, autoregulation of the splanchnic organs' perfusion is less developed compared to the cerebral and renal system, which makes the splanchnic bed more prone to perfusion decrease and ischemia in cases of volume depletion or poor circulation. If RSO2 is measure in the liver, the solid organ reflecting the splanchnic bed perfusion status, hsPDA may be more readily identified than when only cerebral and/or renal RSO2 is monitored.

This study aims to evaluate the usefulness of liver RSO2 measurement in assessing the hemodynamical significance of patent ductus arteriosus in preterm infants, in comparison to cerebral and renal RSO2.

Inclusion Criteria:

• Gestational age at birth less than 32 weeks
• Birthweight less than 1,500 grams

Exclusion Criteria:

• Major congenital anomaly
• chromosomal / genetic anomaly

Preterm infants born at less than 32 weeks' gestation and/or 1,500 grams at birth, who accepts informed consent from the their legal guardians (parents) will be included. Those with major congenital anomaly or genetic abnormality who are at high risk for adverse outcome and compensated circulatory status will be excluded.