[Clinical study on uterine cervix ripening with hyaluronidase and animal experimentation on mechanism of action].

The clinical course of labor in 53 cases with cervical injection of hyaluronidase (HD) and 51 cases with intravenous infusion of oxytocin to ripen the cervix was studied. The success rate of HD group (92.5%) was significantly higher than that of control group (62.8%). HD was without adverse side effects, and did not induce uterine contraction and therefore was preferable for high risk pregnancy cases. This method needed less time for cervical priming than others. The drug is easily available, not expensive and the method is simple. The animal experiments showed the mechanism of action of cervical ripening by HD was probably as follows: (1) the dissociation of ground substance in cervical connective tissue; (2) The destruction of blood vessels permit the migrating of leucocytes to surrounding tissue and resolve collagen; (3) stimulation of cervical fibroblasts to release prostaglandin.