Half an hour of fetal movement in the middle of the night when a woman is 30 weeks pregnant indicates excessive fetal movement and the presence of intrauterine hypoxia. Generally speaking, the normal range of fetal movement is 3~4 times per hour, and 30~40 times in 12 hours. If the fetus continues to move for half an hour, it indicates that there may be intrauterine hypoxia, which may be caused by umbilical cord around the neck, abnormal placenta, and too little amniotic fluid. If there is more fetal movement, change the position to left lateral recumbency, inhale oxygen to provide enough oxygen for the fetus, and seek medical attention in time. When pregnant women find that the fetal movement is obviously abnormal, they need to go to the hospital in a timely manner, under the guidance of the doctor, improve the relevant examination, clarify the specific causes, and take timely and effective methods of targeted treatment, to prevent the death of the fetus and other abnormalities.