The maturity of the cervix is judged by the obstetrician through vaginal examination, which is usually performed at the time of labor, after disinfecting the vulva, to understand the length, position, texture, dilation and the height of the previa. If the score is greater than 9, all are successful, with a success rate of 80% for a score of 7-9, 50% for a score of 4-6, and failure for a score less than or equal to 3. If the cervix is immature, medications that promote cervical maturation are also used to mature the cervix so as to increase the success rate of vaginal trial of labor.