Sperm suspension is a highly ultrasonically visible material: a novel model to study uterine activity.

Background: The aims of this study were to find an ultrasonically echogenic material to study the uterine activity, and to test whether closing the vaginal speculum on the cervix prevents the displacement of the injected material.

Methods: A concentrated sperm suspension was used as an ultrasonically visible material. Forty-five women undergoing intrauterine insemination were randomized into: open speculum group (n=23) and closed speculum group (n=22).