PREDICTION OF CERVICAL CERCLAGE OUTCOME BY ENDOVAGINAL ULTRASONOGRAPHY

OBJECTIVE: We hypothesized that shortened upper cervical segment lengt h, measured by endovaginal ultrasonography, identifies patients with c ervical cerclage at greater risk of preterm delivery. STUDY DESIGN: A total of 121 endovaginal ultrasonographic examinations were performed on 32 patients after cervical cerclage. Ultrasonographic measurements included length of the closed cervical canal segments above and below the cerclage and dilatation of the internal cervical os (funneling) wi th and without fundal pressure. The risk of preterm delivery was teste d by Fisher's exact test (two-tailed). RESULTS: Development of funneli ng of the internal os and shortening of the upper cervical segment len gth were the most predictive of outcome in patients with cervical cerc lage. Twelve patients had shortening of the upper cervical segment (le ss than or equal to 10 mm) before 30 weeks' gestation (mean 22.6 +/- 2 .7 weeks), whereas 20 patients continued to have upper cervical segmen t measurements >10 mm. A short upper cervical segment before 30 weeks' gestation was associated with a significantly higher risk of preterm delivery before 36 weeks (58% vs 10%, p = 0.006) and before 34 weeks ( 50% vs 5%, p = 0.006). CONCLUSION: Endovaginal ultrasonographic assess ment of the cervix in patients with cervical cerclage is a useful adju nct for predicting outcome and for counseling the patient.