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

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.

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). Mimicking embryo transfer, 50 ul of concentrated sperm suspension was injected intrauterine while the vaginal speculum was open in 23 patients. In the other group, the two blades of the vaginal speculum were closed on the cervix, then 50 ul of concentrated sperm suspension was injected. The ultrasonically visible material was observed in the uterine cavity for 10 min during which the procedure was video-recorded.

The injected sperm suspension was clearly visible in all cases. In the closed speculum group, the echogenic droplet remained in the upper uterine segment in 18 cases (82%) and moved towards the lower uterine segment in six cases (18%). In the open speculum group, the echogenic droplet remained in the upper uterine segment in only six cases (26%) and it moved towards the lower uterine segment and passed through the cervical canal in 17 cases (74%).

For the first time in the medical literature, a concentrated sperm suspension was used as an ultrasonographically visible material to study uterine activity. Closing the portio-vaginalis of the cervix prevents the displacement of the injected material.