Fetal movement at 30 weeks’ gestation is considered to be caused by the limited range of movement of the fetus in the uterine cavity, hypoxia in the uterine cavity of the fetus, and high amniotic fluid volume. 1. limited range of intrauterine activity: due to the increased size of the fetus in the late stages of pregnancy, it is easy for the fetus to move less in the uterus, and then it is easy to reduce the fetal movement. 2. Fetal hypoxia in the uterine cavity: for example, poor blood supply to the umbilical cord or knotting of the umbilical cord can easily cause fetal hypoxia in the uterine cavity and reduce fetal movement. 3. More amniotic fluid: more amniotic fluid in late pregnancy, the fetus is farther away from the uterine wall, this situation will cause fetal movement when the pregnant woman is not easy to feel, self-conscious fetal movement is reduced. Decrease in fetal movement need to be timely consultation to do ultrasound and monitoring of the fetal heart to determine whether the fetus is abnormal, abnormalities can be intervened as soon as possible to avoid delays in the condition.