Induction of labor in late pregnancy is the initiation of labor by means of drugs and other means before natural labor to achieve the purpose of delivery. It is a measure taken to release the fetus from the adverse intrauterine environment early and to relieve the pregnant woman of any comorbidities or complications. Induction of labor in late pregnancy is one of the most common means of dealing with high-risk pregnancies in obstetrics, and its success depends mainly on the maturity of the cervix. However, if it is not properly applied, it will endanger the health of both mother and child, and there are potential risks to both mother and child, such as increasing the rate of cesarean section and the incidence of fetal distress, etc. Therefore, the indications for induction of labor should be strictly controlled and the operation should be standardized to reduce the occurrence of complications. This guideline provides evidence-based recommendations for cervical maturation and induction of labor in late pregnancy. The main indications for induction of labor are: 1. delayed pregnancy (those who have reached 41 weeks of gestation and are still not in labor) or overdue pregnancy. 2. Maternal diseases, such as severe diabetes, hypertension, kidney disease, etc. 3. Premature rupture of membranes, not yet in labor. 4, fetal factors, such as suspected fetal distress, placental dysfunction, etc. 5, stillbirth and serious fetal malformation. (2) Contraindications to induction of labor: 1. Absolute contraindications: pregnant women with severe comorbidities and complications who cannot tolerate vaginal delivery, such as: (1) history of uterine surgery, mainly classical cesarean section, unknown uterine incision cesarean section, myomectomy penetrating the endometrium, history of uterine rupture, etc. (2) Placenta praevia and placenta praevia. (3) Significant cephalopelvic disproportion. (4) Abnormal fetal position, transverse position, breech position at first birth estimated to be unable to deliver vaginally. (5) Cervical invasive carcinoma. (6) Certain infectious diseases of the reproductive tract, such as herpes infection in its active stage. (7) Untreated acquired immunodeficiency virus infection. (8) Allergic to drugs used to induce abortion. 2. Relative contraindications: (1) History of lower uterine cesarean section. (2) Breech position. (3) Excessive amniotic fluid. (4) Twin or multiple pregnancies. (5) The number of deliveries is greater than or equal to 5 times. 1. Strictly grasp the indications for induction of labor. 2, carefully check the expected date of delivery, to prevent artificial preterm delivery and unnecessary induction of labor. 3, determine the maturity of the fetus: if the fetal lung is not mature, if the situation allows, as far as possible to promote fetal lung maturity before induction of labor. 4, detailed examination of pelvic size, i.e., morphology, fetal size, fetal position, cephalopelvic relationship, etc., to exclude contraindications to vaginal delivery. 5, fetal heart monitoring and ultrasound should be performed before induction of labor to understand the intrauterine condition of the fetus. 6.Pregnancy combined with medical diseases and obstetric complications, before induction of labor, the severity of the disease and the risk of vaginal delivery should be fully estimated, and the corresponding examination should be carried out, and a detailed prevention and treatment plan should be formulated. 7, medical and nursing staff should be proficient in various methods of induction of labor and the early diagnosis and management of its complications, to closely observe the labor process, make detailed records, and be equipped with personnel and equipment for vaginal assistance and cesarean section during induction of labor. Evaluation of cervical maturity The commonly used method to assess maturity is Bishop’s score, with a score greater than or equal to 6 indicating cervical maturity. The higher the score, the higher the success rate of induction of labor. A score of less than 6 indicates that the cervix is immature and needs to be promoted V. Methods to promote cervical maturation (a) Prostaglandin preparations to promote cervical maturation If the cervical score is <6, then cervical maturation should be promoted. The main mechanism of pg for cervical maturation is to soften the cervix by changing the extracellular matrix components, such as activation of collagenase, which is the dissolution of collagen fibers and increase of matrix; secondly, it affects the smooth muscle of the cervix and uterus, causing relaxation of the smooth muscle of the cervix, dilatation of the cervix, contraction of the smooth muscle of the uterine body, and pulling the cervix; thirdly, it promotes the formation of intercellular smooth muscle of the uterus. formation of gap junctions. Prostaglandin preparations currently in clinical use are: (1) PGE2 preparations such as intravaginal suppositories (controlled-release dinoprostone suppositories, trade name: Probeson); (2) PGE1 type preparations such as misoprostol. All of these drugs are used in Western countries to promote cervical maturation. At present, controlled-release dinoprostone suppositories have been approved by the U.S. Food and Drug Administration (FDA) and the Chinese Food and Drug Administration (SFDA) for the promotion of cervical maturation before induction of labor in late pregnancy. In recent years, misoprostol has been widely used to promote cervical ripening, and a lot of studies have been conducted on it in China and the United States, which proved that it is safe and effective for reasonable use. (1) Controlled-release dinoprostol suppository, a controlled-release prostaglandin E2 preparation, contains 10mg of dinoprostol, slowly released at a rate of 0.3mg/h, and stored at low temperature. (1) Advantages: Controlled release of the drug, easy to remove when contractions are too strong or too frequent. (2) Application method: After vulva disinfection, place the controlled-release dinoprostone suppository deep in the posterior vaginal vault and rotate it by 90 E Gu Liang Roach Roach basket. The termination band should be 3cm in length to facilitate removal. After the drug is placed, the pregnant woman is asked to lie flat for 20-30 min to facilitate the absorption of water expansion. 2h after review, still in the original position after the activity can be. (3) The following conditions should be removed in time: ①. Labor is approaching. ② after 12h placement. ③If there are too strong and too frequent contractions, allergic reaction or abnormal fetal heart rate. ④If the contractions are too strong or too frequent after removal and still not relieved, use contraction inhibitors. 2. Misoprostol: It is a synthetic prostaglandin E1 analogue, available in 100ug and 200ug tablets, mainly used to prevent and control peptic ulcers, and a large number of clinical studies have confirmed that it can be used to promote cervical maturation in late pregnancy. The practical misoprostol for cervical ripening has the advantages of low price, stable nature and easy preservation, and long duration of action, which is especially suitable for application in primary care institutions. Although misoprostol is not approved by FDA and SFDA, the American College of Obstetricians and Gynecologists (ACOG) has reiterated the standard for the use of misoprostol in obstetrics and gynecology in 2003, and in light of the standard of ACOG 2003 and the clinical experience of misoprostol in China, members of the Obstetrics and Gynecology Section of the Chinese Medical Association and related experts have discussed it for many times. The application of misoprostol to promote cervical maturation in late pregnancy was formulated as follows: (1) It is used for pregnant women who need to induce labor in late pregnancy and have immature cervical conditions. (2) The intravaginal dose of misoprostol should be 25ug each time and the drug should not be crushed into pieces when it is released. If there are no contractions after 6h, a vaginal examination should be performed before repeating misoprostol to reassess the cervical maturity and to see if the originally placed drug is dissolved and absorbed. If it is not dissolved and absorbed, it should not be reapplied. The total daily amount should not exceed 50ug to avoid excessive drug absorption. (3) If additional indocin is required, it should be done more than 4 hours after the last misoprostol placement and vaginal examination should confirm that the drug has been absorbed. (4) Those using misoprostol should be observed in the delivery room to monitor contractions and fetal heart rate. In case of too strong or too frequent contractions, vaginal examination should be performed immediately and residual medication should be removed. (5) It is prohibited for those who have a history of cesarean delivery or a history of uterine surgery. 3. Precautions for the application of prostaglandin preparations for cervical maturation: (1) Contraindicated in pregnant women with heart disease, acute liver and kidney disease, severe anemia, glaucoma, asthma, and epilepsy. (2) Prohibited for those with a history of cesarean section and other uterine surgery. (3) Prostaglandin preparation is contraindicated in cases of premature rupture of membranes. (4) The main side effect is too frequent and too strong contractions. Observe and record the contractions, and remove the drug from the vagina promptly if you find that the contractions are too strong or too frequent and the fetal heart rate is abnormal, and use contraction inhibitors if necessary. (5) Those who have already gone into labor should take out the cervical ripening drugs in time. (ii) Other methods to promote cervical maturation The main method is mechanical dilation, and there are many types, including low level water bladder, Foleys tube, kombucha strips and seaweed stick, which need to be used only when the vagina is free of infection and the fetal membranes are intact. It is mainly used to promote the softening and maturation of the cervical canal by mechanically stimulating the canal and promoting the synthesis and release of local endogenous prostaglandins in the cervix. The disadvantage is the potential for infection, premature rupture of membranes, and cervical injury. Sixth, the induction of labor by intravenous drip of contractions, small doses of intravenous contractions for safe and common methods of induction of labor, but in the cervical immaturity, induction of labor is not effective. Its characteristics are: the dose can be adjusted at any time, to maintain the physiological level of effective contractions, once the occurrence of a can be stopped at any time, the contraction of the short duration of action, the half-life of about 5 to 12min. 1, induction of labor method: intravenous drip contraction recommended to use a low dose, preferably using an infusion pump. The starting dose is 2.5mu/min, adjust the drip rate according to contractions, generally every 30min until effective contractions occur. The criteria for effective contractions are 3 contractions within 10 min and each contraction lasts 30-60 s. The maximum titration rate should not exceed 10 mu/min, and if the maximum titration rate is reached, the concentration of contraction can be increased if no effective contraction occurs. The method of increasing the concentration is to add 5u contraction in 500ml of 5% glucose, that is, 1% contraction concentration, equivalent to 10mu contraction per ml of liquid, first reduce the titration rate by half, and then adjust according to the contraction situation, increase the concentration, the maximum to 20mu/min, in principle, no longer increase the titration rate and concentration. 2. Precautions: (1) Observe the contraction intensity, frequency, duration and fetal heart rate changes and record them in time, and perform fetal heart monitoring after adjusting contractions. After rupture of membranes, observe the amount of amniotic fluid and the presence and extent of fetal fecal contamination. (2) Be alert to allergic reactions. (3) Forbid intramuscular injection, subcutaneous acupuncture point injection and nasal mucosal administration. (4) The dosage should not be too large to prevent water intoxication. (5) The contractions are too strong to stop the contraction in time, if necessary, use contraction inhibitors. VII. Artificial rupture of membranes to induce labor Artificial methods to rupture the fetal membranes, causing the release of prostaglandins and contractions to induce contractions. It is suitable for pregnant women with a mature cervix. The disadvantage is that it may cause prolapse or compression of the umbilical cord, maternal and infant infection, anterior vascularity, rupture and fetal injury. Not suitable for pregnant women with head floating. Vaginal infection should be ruled out before rupture of membranes. The membranes should be broken between contractions to avoid rapid outflow of amniotic fluid causing cord prolapse or placental abruption. The fetal heartbeat should be listened to before and after rupture of membranes, and amniotic fluid properties and fetal heartbeat should be observed after rupture of membranes. If the effect of manual rupture of membranes alone is not good, intravenous injection of contraction can be added. The management of labor process and precautions in the induction of labor 1, the induction of labor should strictly follow the operation specifications, strictly grasp the indications and contraindications, and strictly prohibit the induction of labor without indications. 2, according to different individuals to choose the appropriate method of induction of labor and drug dosage, drug delivery route. 3, not arbitrarily change and additional dose. 4.Operate accurately and without error. 5, close observation of the labor process, careful recording. 6, once in labor routine fetal heart monitoring, analyze the monitoring results at any time. 7.If contractions are too strong, too frequent, overstimulation syndrome, fetal distress, obstructed labor, uterine aura rupture, amniotic fluid embolism, etc., stop the application of oxytocic drugs immediately. (2) Immediately lie on the left side, administer oxygen and intravenous fluids (without contractions). (3) Give intravenous uterine relaxant, such as hydroxybenzylhydroephedrine or 25% magnesium sulfate, etc. (4) Immediately perform vaginal examination to understand the progress of labor, and give artificial rupture of membranes if the membranes are not broken, and observe whether the amniotic fluid is contaminated with meconium and its degree.