晚期妊娠引产是产科工作的一个重要组成部分。目前催产素是多年来常规引产的药物 ,但需静脉用药 ,专人管理 ,定时调节剂量 ,且用药时间较长 (1～ 3ｄ)。米索前列醇可致宫缩过强 ,胎儿宫内窘迫 ,剂量难以控制。低位水囊压迫内膜 ,剥离胎膜来引起前列腺素合成[1] 。我医院用低位 Induction of labor during late pregnancy is an important part of obstetric work. At present, oxytocin is a medicine that has been introduced for a long time in many years. However, it needs to be administered intravenously and managed by a single person. The dose is regularly adjusted and the medication takes a long time (1-3 days). Misoprostol can cause too strong contractions, fetal distress, the dose is difficult to control. Low water sac compression endometrial stripping membranes to cause prostaglandin synthesis [1]. I use the hospital low