It is recommended to consult a doctor in time to clarify the cause and give reasonable treatment and treatment. 1. Precursors of childbirth: a hard belly with fetal movement at 36 weeks may be a contraction, which can be shown as an initial interval of about 10 minutes, and then the duration of the pain gradually lengthens to 40-60 seconds, and the degree of pain also increases. The duration of the contractions then increases to 40-60 seconds and the intensity increases, with the intervals shortening to 3-5 minutes. When abdominal pain occurs during uterine contractions, the lower abdomen may feel hard, and the pain may spread to the lower abdomen, or there may be back pain and a feeling of defecation, so you should go to the obstetrics department of the hospital to monitor the fetal heartbeat, fetal movement, placenta, amniotic fluid volume and the opening of the uterus. If the strong and powerful contraction of the uterus leads to a gradual increase in pressure in the uterine cavity, the opening of the uterus opens wide, the head drops, causing the rupture of the fetal membrane and the flow of amniotic fluid from the vagina, this is a precursor to delivery, and pregnant women and their families should be prepared for delivery; 2, pseudo contractions: if a pregnant woman stands or sits in the same position for a long time, she will feel a burst of hardening of the abdomen, which is a pseudo contraction and can be accompanied by fetal movement. If the number of contractions per hour is about 10 times, it is more frequent contractions, you should go to the hospital in time to identify the nature of contractions by the doctor to prevent preterm delivery, if the number of contractions is not very frequent, no abdominal pain, pay attention to rest. After 36 weeks, pregnant women should pay attention to go to the hospital for weekly maternity checkups and monitor the fetus in the womb by doing fetal heart monitoring. In addition, in the second trimester, pregnant women should pay attention to avoid strenuous activities and excessive exertion to avoid the phenomenon of preterm labor.