colour doppler ultrasound pregnancy in hindi factories

For a variety of reasons, the placenta may not grow into a lush tree of low resistance vessels, much like a tree planted in one’s yard that fails to grow as splendidly as the other trees. The origin of uteroplacental dysfunction is often determined in the earliest weeks of pregnancy following embryo implantation. Increased placental resistance impedes this exchange. However, the above-described transfer of nutrients and waste products occurs through multiple mechanisms. The mother’s blood and the fetus’s blood do not mix. This is referred to as reversed end-diastolic flow (REDF).Ī normally developed placental should be a tree of blood vessels demonstrating low resistance, whereby oxygen, carbon dioxide, electrolytes, nutrients and waste products easily are exchanged between the mother’s blood vessels and the fetus’s blood vessels. By convention, the “teeth” or waveforms pointing downward represent blood flow temporarily moving in the opposite direction than which it was intended to move. Remember, the “teeth” are just layperson vernacular for waveforms. Instead of “gaps between teeth” as one might see in absent end-diastolic flow, there will appear to be “teeth” pointing up as well as “teeth” pointing down. In extreme clinical situations, such as severe intrauterine growth restriction, the arterial blood flow can actually reverse directions at the end of diastole. The term “intermittent” is then added to describe this situation, as in intermittent absent end-diastolic flow.įlow in the umbilical arteries should be in the forward direction in normal circumstances. In certain clinical scenarios, AEDF may be present in some, but not with each heart cycle waveform. In AEDF, on the ultrasound screen, the waveform will appear like teeth, but with a gap between each tooth. Depending on the clinical circumstances, it is possible for there to be no flow present in the artery at the end of diastole, referred to as absent end-diastolic flow (AEDF). The peak of the wave represents systole, while the nadir represents end-diastolic flow. The waveform made by measuring the speed of blood flow will have a characteristic sawtooth pattern on the ultrasound screen. Diastole (D), meaning the filling of the heart, is measured at the end, just before another contraction. In Doppler ultrasound, the burst of blood flow when the heart contracts then ejects blood is measured as the systolic blood flow (S). This burst of flow that occurs when the heart contracts then ejects blood is what is being sensed when someone checks our pulse. During diastole, the speed of blood flow through the body will gradually diminish, reaching a nadir at the end of the filling cycle, referred to as end-diastolic flow, before returning to maximum speed with the next heart contraction. The ventricle then begins filling again, referred to as diastole. The speed will be at its maximum when the heart initially ejects blood from the left ventricle, called systole. Regardless of the artery assessed, the speed of blood moving through the artery will vary during each cardiac cycle. Arterial blood flow, however, is quite different. Venous flow is largely uniform, without changes during the heart cycle, unless the fetus is “practice” breathing or an adverse clinical situation exists, such as intrauterine growth restriction. Blood flow in the arteries has a different appearance than blood flow in veins. Thus, some providers use the term Doppler velocimetry, the measurement of speed.ĭuring pregnancy, Doppler ultrasound might be used to assess blood flow to the maternal uterus or, more commonly, blood flow in the fetus. The “sound” those red blood cells emit is based on their speed or velocity. In Doppler ultrasound, the red blood cells are akin to the first responder’s vehicle, racing from location to location throughout the body. The pitch and volume then decrease once the vehicle passes to the point where the sound can no longer be heard when the siren is far enough away.

Imagine how the siren’s sound changes from when it first grabs our attention from far away, gaining in volume and pitch as the vehicle approaches, reaching a peak as it passes us. Think about the last time you saw an approaching ambulance or fire truck, lights flashing, sirens blaring. Most of us are unaware that the Doppler principle is part of our daily lives, for example, in how we hear the sirens of first responders.

Colour doppler ultrasound pregnancy in hindi factories