top of page

Use of a Uterine Sound

The Purpose of a Uterine Sound 

  • Insures that you can pass through the internal os

  • Informs the direction and pathway through the os up to the fundus

  • Measures the depth/distance from the external os to the fundus

  • Is appropriate for IUD placement not <5.5 cm. 10 cm or more in some cases

  • Tells you where to set the flange so you don't waste the IUD

Which one?


  • Usually 4mm (occasionally 3mm)

  • Metal sound - can be bent to mimic uterine flexion

  • Plastic sound - may be less likely to perforate

  • Endometrial sampler - thinner diameter

Hand Skills


  • Avoid momentum

  • Hold it like a pencil or dart

  • Use Wrist action - not elbow; not shoulder​

  • Brace fingertips on speculum to achieve control of force while advancing the sound

Safety Tips


  • Don’t push hard at internal os

  • Do not force

  • Slow progression through the internal os

  • Once you have passed through the internal os, stop....and then, intentionally proceed to the fundus

To download a PDF version of this page, click here.

bottom of page