[Evaluating the cervix in pregnancy using vaginal sonography. Studies of cervix insufficiency]. / Die Beurteilung der Zervix in der Schwangerschaft mit Hilfe der Vaginalsonographie. Untersuchungen zur Zervixinsuffizienz.

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.

[Transvaginal echography. An application in the diagnosis of cervical incompetence]. / L'échographie transvaginale. Un apport dans le diagnostic de la béance du col utérin.

It has already been demonstrated that abdominal ultrasound is an adequate method for measuring the cervix in pregnancy. The use of the vaginal route for such measurement is new. We have been using for the vaginal approach an ultrasound transducer of 5 mHZ with an angle of sweep of 240 degrees. The study was carried out on 23 pregnant women at the 28th week of pregnancy who had been admitted because of threatened premature labour with possible cervical incompetence; and on 20 cases of normal pregnancy also at the 28th week, which is the time when we do glucose estimations normally in our antenatal clinics. The result of our work shows that this ultrasonic method through the vagina gives us much more accurate measurements of the cervix than digital vaginal examination does. A mean difference of 12.3 mm in the length of the cervix was found in normal pregnancies (46.3 mm) and in cases where there was a question of cervical incompetence (34 mm). Furthermore the phenomena of shortening, dilatation of the cervix and a funnel-shape of the internal os are ultrasound signs of value in diagnosing incompetent cervix. Further advantages of the transvaginal approach are that there is no need for the bladder to be filled previously, and that the organs are nearer which improves the ultrasound picture. All the same, it is to be emphasized that transvaginal ultrasound can only be a factor to be added to clinical examination in the diagnosis of the incompetent cervix.