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abdominal phonogram, antenatal monitoring, biophysics, fetal cardiotachogram, fetal heart rate, fetal heart sounds, fetal phonocardiogram, fPCG, placental function


This brief technical note describes a design concept for a low-cost, painless, noninvasive monitor of total placental blood flow during the third trimester of pregnancy. The approach may offer an overlooked solution to a central problem of the human placenta project. A systems level biophysical analysis shows that jets of blood flow emerging from spiral arteries in the placenta generate characteristic 1/f or “pink noise” which is routinely audible, but typically ignored, during fetal phonocardiography. The amplitude of the 1/f noise, recorded at a standardized location in an individual patient, is a measure of total placental blood flow that is potentially useful for monitoring of placental function and better management of third trimester complications such as preeclampsia and maternal diabetes.