Reference data representative of normal findings at two-dimensional and three-dimensional gray-scale ultrasound examination of the cervix from 17 to 41 weeks' gestation.
Objectives To create reference values representative of normal findings on two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasound (TVS) examination of the cervix from 17 to 41 weeks' gestation and to determine the agreement between cervical measurements taken by 2D and 3D TVS. Methods Cross-sectional study covering 17 to 41 weeks in 419 nulliparous and 360 parous women who deliver