Three-dimensional Ultrasounsd Imaging Of The Normal Fetal Anal Canal

ObjectiveTo identify fetal pelvic floor structures especially anal sphincter complex with current threedimensional (3D) ultrasound (US) technology.Methods3D ultrasound was performed with abdominal transducer with multiplanar display in 100 fetuses at 22-39 gestational weeks. The fetal pelvis scans performed were analyzed from rapid automated volume acquisition performed during routine exams of fetuses with normal survey of systems.ResultsIn all cases we were able to reveal the anal sphincter complex however it was impossible to differentiate between internal anal sphincter (IAS) and the external anal sphincter (EAS) in most cases. We performed the measurement of the diameter of the anal sphincter complex.Conclusions3D US is an excellent diagnostic modality for demonstrating and analyzing the fetal anal canal (anal sphincter complex and levator ani muscle). Our findings may be used as a normal basis for future pathological findings in the fetal anal region using 3D US.