Transvaginal Versus Transperineal Ultrasonographic Examination of the
Cervix at 15-32 Weeks of Gestation: A Blinded Comparison
Oluş APİ1, Orhan ÜNAL1, Mustafa ALTUNDAĞ1, Murat APİ2, Birol CENGİZOĞLU1, Cem TURAN1
İstanbul-Turkey
OBJECTIVE: The objective of this study was to determine the correlation and agreement between transperineal ultrasonography and transvaginal ultrasonography in the assessment of cervical length in gravid patients.
STUDY DESIGN: We performed a prospective, blinded comparison of transvaginal and transperineal cervical ultrasonographic assessment. Unselected gravid women at 15-32 weeks of gestation who attended for routine antenatal care were sequentially examined by 2 sonographers using an endovaginal and a curvilinear probe. For each patient the initial sonographer and examination method were randomly assigned. The sonographer who performed the second examination was blinded to the results and images from the first examination. The Pearson correlation coefficient was used to determine the relation between the transvaginal and transperineal cervical length measurements and Student's t test was used to determine the statistical significance of the differences between the mean cervical length measurements.
RESULTS: 100 women were studied at a mean of 23.9±4.7 weeks of gestation. Transperineal and transvaginal mean cervical lengths were 34.3±5.77 mm., 37.29±6 mm.; respectively. The Pearson correlation coefficient was 0.75. In 55% of cases the intermethod difference was < 10%. The mean difference between the paired transvaginal and transperineal cervical lengths was 2.9±4.16 mm. and the difference was calculated to be statistically significant (p=0.00067).
CONCLUSION: Cervical length measured by transperineal ultrasonography demonstrates close correlation with transvaginal measurements. With optimal technique, transperineal cervical length observations can be expected to be approximately 3mm. shorter than a given paired transvaginal measurement. Transperineal ultrasonography may be a preferred method of cervical length assessment for situations in which vaginal instrumentation is liked to be avoided.
(Gynecol Obstet Reprod Med 2005; 11:10-13)
Key Words: Cervical length, Transvaginal, Transperineal, Ultrasonography
