Babies who are born very prematurely are often born with murmurs in the heart. In preterm babies, one of the most common causes of murmur is the presence of a PDA. This is the persistence of a connection that normally exists in the baby before it is born, connecting between the major blood vessels that leave the heart. In term babies, this channel closes shortly after birth when normal adult circulation is achieved. However, in preterm babies, the PDA can remain open, which can lead to multiple problems in the baby. Our current standard of treatment in the Neonatal Intensive Care Unit (NICU) is to perform cardiac ultrasound (echocardiogram) in all babies less than 29 weeks gestation to diagnose the presence of hsPDA. We also use an echocardiogram to follow the PDA until complete closure. If present, the standard treatment in the NICU is to give medication, usually Ibuprofen, a non-steroidal anti-inflammatory drugs (NSAID), to close the PDA. Near-infrared spectroscopy (NIRS) is a new type of device to detect oxygenated blood supply to the brain, kidney, and abdominal regions. This device is used to assess the effects of Ibuprofen on oxygen supply to these three regions.