Fetal heart sounds of 170-180 are at some risk. Fetal heart sounds are biphonic, like the ticking of a clock, and fast, with a normal value of 110-160 beats per minute. When the fetal heart sound is greater than 160 beats per minute or the fetal heart sound is less than 110 beats per minute, except for the fetal movement and other conditions, suggesting that the fetus may have intrauterine distress, the fetus in the uterine cavity may be acute or chronic hypoxia, which in turn causes changes in the fetal heart sound, pregnant mothers should pay attention to. There are many causes of intrauterine hypoxia, such as the presence of hypertension, chronic nephritis, premature rupture of membranes, etc., and the umbilical cord of the fetus is too long, entangled or knotted. But assessing the fetal heart sound, can not be determined at once, should be examined several times to change the position for a few minutes, after which to the regular hospital for timely consultation.