Ledger W L, Webster M, Harrison L P, Anderson A B, Turnbull A C
Am J Obstet Gynecol. 1985 Feb 1;151(3):397-402. doi: 10.1016/0002-9378(85)90311-4.
Surgical transection of the cervix was done on eight ewes in late pregnancy. This procedure resulted in most of the length of the cervix being mechanically disconnected from the uterus. Labor was induced by injection of dexamethasone phosphate into a fetal hind limb during operation in four of the eight ewes. The success of the induction of labor was confirmed by observation of increased uterine activity and by measurement of the concentrations of progesterone and 17 beta-estradiol in peripheral plasma. Ewes were put to death approximately 48 hours after injection of dexamethasone and the extensibility of the isolated portion of the cervix was determined. Cervices taken from ewes in which labor had been induced were found to have softened considerably compared to control cervices taken from ewes in which the cervix had been transected without induction of labor. The results suggest that cervical softening can still occur during labor in the absence of any direct mechanical or local vascular connection between the cervix and uterus.
在妊娠晚期，对八只母羊进行了子宫颈手术切断。该手术导致子宫颈的大部分长度与子宫机械性分离。在八只母羊中的四只手术过程中，通过向胎儿后肢注射磷酸地塞米松诱导分娩。通过观察子宫活动增加以及测量外周血浆中孕酮和17β-雌二醇的浓度，证实了引产成功。在注射地塞米松后约48小时处死母羊，并测定分离的子宫颈部分的伸展性。发现与未引产而进行子宫颈切断的母羊的对照子宫颈相比，引产母羊的子宫颈已明显软化。结果表明，在子宫颈与子宫之间没有任何直接机械或局部血管连接的情况下，分娩期间子宫颈仍可发生软化。
