In vivo measurements of uterine cavities in 795 women of fertile age.

The uterine sound length, the functional length of the cervix including the zone of internal cervical os and the fundus transversal were determined in 795 fertile women in vivo using a measuring device, the Cavimeter. The functional cavity length was calculated by subtracting the functional length of the cervix from the uterine sound length. With growing parity, the uterine length and width increase, but with advance in age, the uterine cavity changes are not so distinct. The wide ranges found by the investigation demonstrate the individuality of the uterine cavity and the desire to measure it prior to fitting an IUD. The use of adapted IUDs according to the size of the uterine cavity leads to a remarkable reduction of side effects, particularly expulsion, bleeding and cramps caused mainly by dimensional incompatibility. Therefore prefit uterine cavity measurement can lead to better efficacy of IUDs, increased rates of acceptance and higher continuation rates.