Development of a new method of insertion of IUD's .
In order to improve to efficiency and to lower the rate of expulsion of the stainless steel ring type of IUD a study of the uterine geometry of 200 cases of repeated expulsion of the IUD was done. A new home-made uterine metrology device which was capable of accurately measuring the longitudinal as well as the transverse diameter of the endometrial cavity at the fundus was used. A group of women of similar age wearing an IUD successfully more than 3 years, but not longer than 15 years, served as controls. Ten women from the group of repeated expulsion of the IUD and 10 women from the control group were examined with X-ray hysterograms. The geometry of the endometrial cavity in the expulsion group was of the dystonia type, similar to a cloth pocket with great depth and loose mouth, while in the control group it was mostly of the triangular type or globular and the tension of the cervix was good. In cases where the transverse diameter of the endometrial cavity at the fundus was too narrow or the longitudinal length of the endometrial cavity was too short, the rate of expulsion appeared high. In order to improve the effectiveness of the IUD, the circle of the ring should be tangentially fitted to the inner surface of the endometrial cavity. This may be calculated according to the following formula: (Formula: see text) A table for selection of size of the IUD according to the new formula is suggested.
D000328:Adult; D005260:Female; D006801:Humans; D007047:Hysterosalpingography; D007433:Intrauterine Device Expulsion; D007434:Intrauterine Devices; D008433:Mathematics; D008722:Methods; D008875:Middle Aged; D014599:Uterus / Q000002:abnormalities