title: Evaluation of the development of the fetal anal sphincter with tomography ultrasonography imaging.
abstract: The aim of the study described here was to examine the potential of tomography ultrasonography imaging (TUI) in evaluation of the fetal anal sphincter. In this prospective cross-sectional study of the fetal anal sphincter with TUI, 326 singleton pregnancies (mean age = 28 y, range: 22-38 y) were scanned at 19-40 wk of gestation. The fetal anal region and ischium were revealed in 320 of 326 patients (98.2%). The normal fetal anal sphincter diameter and ischial space reached maximums of 15 and 39 mm, respectively. The normal fetal anal sphincter diameter and the ischial space were plotted as a function of gestational age (GA) on a linear curve, and the regression equations for normal fetal anal sphincter diameter and ischial space as a function of GA in weeks were obtained. A scatterplot was also created that revealed a significant positive relationship between normal fetal anal sphincter diameter and ischial space. On the basis of these criteria, imperforate anus was diagnosed in one fetus. Ultrasonographic assessment of the fetal anal sphincter and the ischium with TUI is feasible. The reference values reported in this article may be useful in prenatal diagnosis of fetal anal sphincter abnormalities.
authors.affiliation: Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Guang
authors.affiliation: GE Healthcare, Shenyang, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China. Electronic address: caial12@sina.com.
authors.forename: Ai-Lu
authors.initials: AL
authors.lastname: Cai
authors.affiliation: Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China.
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Xie
authors.affiliation: Department of Public Health, China Medical University, Shenyang, China.
authors.forename: Hai-Long
authors.initials: HL
authors.lastname: Ding
authors.affiliation: Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China.
authors.forename: Xin-Yue
authors.initials: XY
authors.lastname: Meng
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000000981:diagnostic imaging* / Q000196:embryology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014054:Tomography / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult
keywords: 3-D ultrasonography; Fetal anal sphincter; Fetal ischial space; Imperforate anus; Prenatal diagnosis; Tomography ultrasonography imaging