In a second pregnancy after a first cesarean delivery, dehiscence of the uterine scar (or rupture of the uterus) may or may not be clinically symptomatic. Rupture of the uterine incision can occur late in pregnancy and is most often seen in scarred uteruses. If the first child was delivered by cesarean section, then the uterus is a scarred uterus; if the uterus was removed by myomectomy before pregnancy, the uterus is also a scarred uterus, but the scar is located in the body of the uterus, so there is a possibility that the uterine incision will be opened (ruptured) in another pregnancy. The following signs may occur when the uterine incision ruptures: 1. abdominal pain and bleeding during pregnancy. Abdominal pain at the site of rupture, pain can occur in the lower abdomen in the rupture of the cesarean scar, and in the rupture of the scar after myomectomy, pain occurs at the scar of the body; pain can be vague or severe, tearing pain, etc., depending on the size of the rupture; bleeding can be vaginal or intra-abdominal bleeding, depending on the blood vessels involved in the rupture, bleeding can be more or less, and the impact on vital signs The bleeding can be vaginal or intra-abdominal depending on the blood vessels involved in the rupture. Therefore, pregnant women with scarred uterus during pregnancy should seek medical attention promptly when they experience pain different from contractions or vaginal bleeding. 2.After the scarred uterus is in labor, excessive contractions or tonic uterine contractions occur during labor, the patient is irritable, breathing and heartbeat are accelerated, severe pain in the lower abdomen is unbearable, the uterus is plate-like and refuses to be pressed, and some will have a small amount of vaginal bleeding with bright red color, suggesting a sign of uterine rupture. 3.Pressure and congestion of the bladder, difficulty in urination and hematuria. 4.Fetal heart monitoring reveals abnormal changes in fetal heart rate, suggesting possible intrauterine hypoxia of the fetus. 5. The appearance of pathological constriction ring is also the main sign of uterine rupture. A transverse ring is formed between the body of the uterus and the lower part of the uterus, and the ring can be seen to rise gradually with contractions, reaching the flat umbilicus or above the umbilicus, and the pressure pain is more obvious. This sign is not usually present during labor in scarred uterus. If you are pregnant again with a scarred uterus, you need to be closely monitored, not to do strenuous exercise, to increase the number of birth examinations, to control the weight gain during pregnancy, to check the thickness of the lower uterine scar by ultrasound in late pregnancy, to comprehensively assess the condition of the mother and child, and to carefully choose the mode of delivery; for pregnant women with the possibility of vaginal delivery, the medical staff will prepare all aspects, strengthen the monitoring during labor, and be prepared for emergency cesarean delivery. However, some of those who chose elective cesarean delivery did have intraoperative findings that the uterine scar had split, but there was no damage to the blood vessels, no internal bleeding, and therefore no symptoms. Therefore, we have to strictly limit cesarean deliveries without surgical indications for the first child.