Patient's question:
After I got pregnant, when I went to the hospital for a prenatal check-up, I heard other pregnant women talking about prenatal check-up sd. I wanted to understand what it means. What is the meaning of prenatal check-up sd?Doctor's answer:
SD is a ratio, specifically the umbilical-cord placental blood flow ratio, which can reflect the blood supply function of the placenta and umbilical cord. In normal late pregnancy, the S/D ratio should not exceed 3. If it is below this value, it may indicate abnormalities. This could be due to poor blood supply caused by umbilical cord compression and high resistance, or poor placental function leading to increased resistance in umbilical blood flow. It is also necessary to carefully examine whether the fetus has any abnormalities.