People often use the phrases “in October, one day of labor” and “ripe for the picking” to describe the delivery after the expiration of pregnancy. Therefore, some women are reluctant to induce labor even when the day has come, and insist on waiting for natural labor. In fact, only about 5% of women who deliver naturally happen to deliver on their due date, and about 85% deliver within two weeks before and after their due date, which is within the normal range. About 10% of women deliver at 42 weeks of gestation, which is called “overdue pregnancy”. The rate of fetal perinatal disease and mortality increases in late pregnancies and worsens with longer gestation, with perinatal mortality at 43 weeks of gestation three times the normal rate and at 44 weeks five times the normal rate. The risk of fetal death is higher in primigravid women than in menstruating women, and therefore it is a high-risk pregnancy. The fetus will continue to develop and grow in the uterus if the function of the placenta has not declined, eventually forming a huge fetus – the fetus weighs more than 4.0 kg, is more than 55 cm in length, has obvious cranial calcification and is not easily deformed. At this time, because the fetus is too large, it will not only increase the difficulty of delivery, but also increase the complications such as intracranial hemorrhage, birth injury, maternal uterine rupture, birth canal laceration, postpartum hemorrhage and puerperal infection. Due to the increased chance of obstructed labor, the chance of surgically assisted labor also increases significantly, and the chance of cesarean delivery increases. 2. In an overdue pregnancy, if the placenta ages and its function declines, the oxygen and nutrition supplied to the fetus through the placenta decreases, resulting in a fetus with less subcutaneous fat, general dehydration, dry, cracked and wrinkled skin and other conditions, like a little old man. These fetuses are prone to intrauterine death, and even if they are born, their health condition is worse than that of a normal delivery, often dying due to dehydration, anemia, lung infection, etc. Due to the lack of oxygen, it can also cause the fetal anal sphincter to relax, so that the meconium is discharged into the amniotic fluid, making the amniotic fluid cloudy, and during delivery, the fetus inhales the amniotic fluid mixed with meconium, which can easily cause neonatal asphyxia and neonatal aspiration pneumonia. The perinatal mortality rate increases, 4 times higher than that of normal pregnancy. 3, amniotic fluid decreased: pregnancy, the uterus is full of amniotic fluid, the fetus lives in the amniotic fluid, so the amniotic fluid is the external environment for the normal growth and development of the fetus, the normal amount of amniotic fluid is one of the signs of a good pregnancy. The amount of amniotic fluid will decrease or even be less than 100 ml after the gestation time increases beyond 42 weeks. The low volume of amniotic fluid is not good for delivery, it can cause slow opening of the uterus and prolong the first stage of labor, and the fetus and umbilical cord are easily pressurized in the uterus, increasing the occurrence of fetal distress. What are the diseases or conditions that predispose to overdue pregnancy? Most authors believe that overdue pregnancy is related to fetal adrenocortical function. The following conditions are likely to lead to an overdue pregnancy: 1. cephalopelvic asymmetry due to poor stimulation of the internal cervical opening and lower uterine segment by the fetal prepubic area; 2. anencephaly: the absence of a hypothalamus in the fetus that results in poor development of the pituitary-adrenal axis, low hormone production by the fetal adrenal cortex, and a small irregular fetal head that is insufficient to stimulate the internal cervical opening and lower uterine segment to cause contractions. The contractions are caused by the low production of hormones by the fetal adrenal cortex and the small size of the fetal head which is insufficient to stimulate the endocervical opening and the lower uterine segment. 3.Lack of placental sulfate enzyme is a rare companion recessive disorder. It is seen in all cases of male pregnancy. The fetal placental unit is unable to convert the less active dehydroepiandrosterone into estradiol and estriol, resulting in an overdue pregnancy. The diagnosis is confirmed when plasma estrogen values are not seen to increase after the administration of dehydroepiandrosterone sulfate to the pregnant woman. 4. Insufficient secretion of endogenous prostaglandins and estradiol and increased levels of progesterone Some authors believe that late pregnancy is due to an imbalance in the ratio of estrogen to progesterone, which inhibits prostaglandins and contractions, causing the uterus not to contract and delaying the onset of labor. How to Avoid Pregnancy During the first six months of pregnancy, you should keep track of your menstrual cycle and the date of your last menstrual period so that you can calculate the exact due date. If your menstrual cycle is not accurate or you do not remember the date of your last menstrual period, you should have an ultrasound to determine the size of the embryo (gestational sac or head and buttock length) as soon as your pregnancy is confirmed in order to estimate the expected date of delivery. The growth of the fetus in the first 3 months is less likely to be influenced by acquired artificial factors (such as the physical condition of the pregnant woman, nutrition, etc.). Therefore, the estimated due date based on the head-rump length value is more accurate. If a pregnant woman goes to the hospital regularly for prenatal checkups and does not go into labor one week after the due date, labor can be induced under close monitoring by a doctor. In this case, in fact, the first thing to determine is whether the expected date of delivery has indeed passed. Some pregnant women are more than 2 weeks past their due date, but the doctor’s examination does not find any signs of overdue pregnancy, so it is likely that they do not remember their periods, or they are irregular or happen to ovulate and become pregnant at the wrong time. What is the height of the uterine fundus, etc.? The answers to these questions can help the doctor to make a correct judgment. In addition, an ultrasound can be done to determine the maturity of the fetus, the age of the placenta and the amount of amniotic fluid, so that the doctor can determine whether the baby should be delivered. If you are past your due date, you must ask your obstetrician to help you deliver the baby as soon as possible and end the pregnancy as soon as possible. Do not stay at home and wait. What should I do if I haven’t given birth after the due date? If you are pregnant and still have no signs of labor, it is advisable to go to the hospital as soon as possible. The physician should do the following: (1) Re-check the expected date of delivery carefully. (2) Any pregnancy complications and complications should be treated promptly first: having pregnancy complications such as pregnancy-associated heart disease, pregnancy-associated nephritis, etc. as well as pregnancy complications such as gestational hypertensive disorders and gestational diabetes mellitus increase the risk to both the mother and the fetus when the pregnancy expires, and the pregnancy should be terminated promptly. (3) Estimate the size of the fetus and determine whether there is cephalopelvic disproportion: if the fetus weighs about 4000g, if the fetus continues to grow after the expiration of pregnancy, it will not be conducive to delivery, and termination of pregnancy should be considered. (4) If there is no such situation, in 40-41 weeks of pregnancy: monitor the fetal condition: check the fetal movement once a day in the morning, in the afternoon and in the evening, for 1 hour each time, multiply the sum of 3 hours by 4 to get the number of fetal movements in 12 hours, if the total number of 12 hours is less than 10, it indicates the possibility of fetal hypoxia, which should be dealt with immediately at the hospital for fetal heart monitoring and ultrasound to monitor the changes of amniotic fluid, if there is abnormal monitoring or too little amniotic fluid, it is necessary to The first of these is the first of a series of tests that will be carried out in the future. All pregnant women who are ≥ 41 weeks pregnant should be hospitalized in time to induce labor, preferably before 42 weeks to end the pregnancy. The mother and her family should work closely with the doctor to induce labor when it’s time to do so, and never wait until the “melon is ripe”.