[Evaluating the cervix in pregnancy using vaginal sonography. Studies of cervix insufficiency].

Transvaginal ultrasound provides important detailed information, which cannot be obtained by routine manual vaginal examination. By measuring the outside-inside distance (from os externum to os internum), we can determine the actual length of the cervix. By depicting the cervical canal, we can identify early dilatation. Visualizing the os internum with a possible opening, forming a conus, helps reveal an incompetent cervix. A total of 485 measurements of the cervix was carried out. Fifty patients with normal clinical findings between 28 and 32 weeks of pregnancy were compared to the same number of patients in the 28th to 32nd week of pregnancy, with the clinical diagnosis of an incompetent cervix. A cervical length of 46.3-39.3 mm was found in normal pregnancies, and a length of 34.0-21.4, when a clinically incompetent cervix had been diagnosed, a difference of 12.3-17.9 mm.