title: Reference values for the cervical length measurement in the second trimester of pregnancy using the transvaginal ultrasound in a large Brazilian population.
abstract: To establish reference values for the cervical length (CL) measurement by transvaginal ultrasound between 20 and 24+6 weeks of gestation in a large Brazilian population. A retrospective cross-sectional study was performed with 996 singleton pregnancies. The CL measurement (mm) using the transvaginal ultrasound was obtained in a sagittal view and the calipers positioned to measure the linear distance between the triangular area of echodensity at the external os and the internal os. The median±standard deviation and ranges for the CL measurement (mm) was 37.0±10.7 (range, 8 to 51). CL measurement did not modify significantly with gestational age. The observed percentiles for the CL measurement (mm) considering all number case were the following: 5th, 28 mm; 50th, 37 mm; and 95th, 45 mm. Reference values for the CL measurement by transvaginal ultrasound between 20 and 24+6 weeks of gestation in a large heterogeneous Brazilian population were established.
authors.affiliation: Mario Palmério University Hospital, University of Uberaba, Uberaba-MG, Brazil.; Radiologic Clinic of Uberaba, Uberaba-MG, Brazil.
authors.forename: Alberto Borges
authors.initials: AB
authors.lastname: Peixoto
authors.affiliation: Mario Palmério University Hospital, University of Uberaba, Uberaba-MG, Brazil.; Radiologic Clinic of Uberaba, Uberaba-MG, Brazil.
authors.forename: Taciana Mara Rodrigues
authors.initials: TM
authors.lastname: da Cunha Caldas
authors.affiliation: Mario Palmério University Hospital, University of Uberaba, Uberaba-MG, Brazil.
authors.forename: Ana Helena Bittencourt
authors.initials: AH
authors.lastname: Alamy
authors.affiliation: Department of Obstetrics and Gynecology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto-SP, Brazil.
authors.forename: Wellington P
authors.initials: WP
authors.lastname: Martins
authors.affiliation: Department of Obstetrics and Gynecology, Federal University of Paraná, Curitiba-PR, Brazil.
authors.forename: Rafael Frederico
authors.initials: RF
authors.lastname: Bruns
authors.affiliation: Department of Obstetrics, Paulista School of Medicine, Federal University of São Paulo, São Paulo-SP, Brazil.
authors.forename: Edward
authors.identifier: 0000-0002-6145-2532
authors.initials: E
authors.lastname: Araujo Júnior
keywords: Cervix uteri; Reference values; Second pregnancy trimester; Transvaginal ultrasound