title: Transperineal versus transvaginal ultrasonographic evaluation of the cervix at each trimester in normal pregnant women.
abstract: OBJECTIVE
  To compare transvaginal and transperineal ultrasonography in the assessment of cervical length and cervical changes in normal gravid patients at each trimester.
  
  
  METHODS
  Transperineal and transvaginal ultrasonographic cervical length was measured on 104 asymptomatic pregnant women between 10 and 14, 20-24, and 30-34 weeks' gestation and the presence of a funnel was also noted. The study used the McNemar chi2 test to assess the difference between two methods in their ability to obtain a measurement, and the Pearson correlation coefficient to determine the relationship between the paired transperineal and transvaginal cervical lengths.
  
  
  RESULTS
  Cervical length measurements were obtained by transvaginal ultrasonography in all 104 patients and by transperineal ultrasonography in 101 patients (97.1%) (P = 0.1). By gestational age, the greatest length discrepancy (2.8 mm) between the two ultrasonographic methods was found at 10-14 weeks (P < 0.001). At 20-24 and 30-34 weeks' gestation, the mean length differences were less than 1 mm (P < 0.01 and P = 0.337, respectively). Cervical funnelling was observed in 16 patients by both methods, whereas in two patients from the 20-24 week gestational age group, funelling was observed by transvaginal ultrasonography and not by transperineal ultrasonography.
  
  
  CONCLUSIONS
  Cervical length measurements by transperineal ultrasonography show good correlation with transvaginal ultrasonographic measurements and it is a satisfactory alternative to a transvaginal evaluation of the cervix throughout pregnancy.
authors.affiliation: Department of Obstetrics and Gynaecology, Abant Izzet Baysal University, Duzce Medical School, Duzce, Turkey. drismailozdemir@yahoo.com
authors.forename: Ismail
authors.initials: I
authors.lastname: Ozdemir
authors.forename: Fuat
authors.initials: F
authors.lastname: Demirci
authors.forename: Oguz
authors.initials: O
authors.lastname: Yucel
mesh_terms: D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D016009:Chi-Square Distribution; D005260:Female; D005865:Gestational Age; D006801:Humans; D010502:Perineum; D011247:Pregnancy; D011264:Pregnancy Trimesters; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014621:Vagina