A bouncing stomach at 30 weeks pregnant is usually fetal movement felt by the pregnant woman as the baby moves around the uterine cavity. In 30 weeks of pregnancy the uterine cavity is not as large as the space in the early stages of pregnancy, so the fetal movement is more obvious and easy to be perceived, and it may be a jump. The first thing to do is to determine whether the beating is regular. If it is regular, it is usually normal. If there is a decrease in fetal movement, then it is an abnormal situation, need and timely consultation to assess whether the fetus is safe. First, normal: 1, regular fetal movement: the fetus in the uterine cavity there is a circadian rhythm, every day will appear in the corresponding fixed time period of regular fetal movement; 2, fetal hiccups: the fetus in the process of swallowing amniotic fluid, sometimes drink too fast, septal muscle stimulation, resulting in hiccups appeared to be a jumping movement; 3, abdominal aortic pulsation: the uterus increases in pregnancy, abdominal aorta is compressed beating significantly, the frequency and heartbeat rate The frequency is the same as the heartbeat frequency. Second, abnormal: if the fetus intrauterine hypoxia, there can be frequent fetal movement, you need to go to the hospital as soon as possible to do fetal heart monitoring, if there is the umbilical cord around the neck or other more serious situation, usually need to take measures as soon as possible to deliver, to avoid the occurrence of intrauterine asphyxiation of the fetus and other more serious situations.