Transvaginal Sonography in Diagnosis of Incompetent Internal Os of Cercix

The diagnosis of cervical incompetency is routinely accomplished by reviewing the clinical history and pelvic examination subjectively. Rescently by using ultrasonography. the objective method in diagnosis of cervical incompetency was developed. Especially, the transvaginal sonography can provide clear visualization of uterine cervix with an empty bladder without distrosion of cervix which was developed when abdominal sonography with distended bladder.

So author performed the study in 46 cases of pregnant women of which menstrual age was 12 weeks to 36 weeks(normal control group 36 cases, risk group 11 cases) during the period of May, 1992 to Febburary, 1993. And these two groups were performed trasvaginal sonography and measured length and diameter of cervix.

And the result were follows ;

1) The mean age was higher in risk group than normal control group, the gestational age was not significantly different between two groups, and the gravity and parity was higher in risk group than normal control group.

2) As measuring the length and diameter of cervical canal by transvaginal sonogram in nullipara and multipara in normal control group, each measurements were not significantly different between nullipara and multipara.

3) The mean length of cervix by transvaginal sonography was 3.0±0.97cm in risk group, 4.7±0.89cm in normal control group and the cervical length was significantly shorter in risk group than normal control group(P<0.01).

4) The mean diameter of cervix by transvaginal sonogram was 2.0±0.37cm in risk group, 0.5±0.21cm in normal control group and the diameter of cervix was significantly greater in risk group than normal control group(P<0.01).

Transvaginal sonographic measurement of cervical length and diameter in diagnosis of incompetent internal os of cervix is noninvasive and relatively objective method.