[A study to lower the expulsion rate of IUDs]

The author has been investigating why the shape and size of the IUD must be suitable to the geometric size and shape of the endometrial cavity. Women vary greatly in the shape and size of the endometrial cavity. When any woman needs to use an IUD, one should measure the transverse as well as the longitudinal diameter of the endometrial cavity at the fundus. One cannot simply depend on the longitudinal length of the vertical axis of the endometrial cavity in choosing the diameter of the ring. The author always uses the uterine metrology device of the GCH-I types to select the diameter of the ring. 1561 women who were wearing IUDs were measured and the probe was used to measure the vertical axis of the endometrial cavity for 1355 women. The women were followed for 3 years. The rate of expulsion of IUDs in the former was 3.9%, and in the latter 6.0. Particularly, the rate of removal in the former because of disease was much lower. There was a marked difference between the two.