There are many reasons for the fetal heart rate of 170 beats/min, which can be roughly divided into two parts, one part belongs to the common physiological phenomenon, which usually does not need special treatment; the other part belongs to the abnormal situation, which can be promptly checked to avoid affecting the health of mother and baby. 1, normal situation: 1, early pregnancy week: if the pregnant woman is in the early pregnancy, the fetus is small, so the fetal heart is slightly faster is a normal physiological phenomenon; 2, fetal movement: if the fetus has just had fetal movement, direct fetal heart monitoring, fetal heart will be slightly faster, if more than the normal 160 times / min, to 170 times / min, also belongs to the normal situation, pregnant women pay attention to regular monitoring can be. Second, the abnormal situation: 1, lack of oxygen: fetal heart is too fast the primary consideration of fetal oxygen deficiency, the causes of oxygen deficiency include fetal umbilical cord abnormalities, low amniotic fluid or too turbid, the pregnant woman lung infection, anemia, various causes of shock, etc.; 2, disease: fetal congenital heart disease, respiratory disease or fetal malformation, fetal heart may also appear 170 times / min; 3, other reasons: pregnant women overdose spicy food, improper medication, emotional overexcitement, overexertion, etc. can affect the fetal heart. If the fetal heart rate is 170 beats per minute occasionally, there is no need to worry too much, just monitor the fetal heart rate regularly during pregnancy checkups, but if the fetal heart rate suddenly accelerates to 170 beats per minute, you must actively look for the cause of the rapid fetal heart rate to avoid affecting the normal development of the fetus.