A new form of intrauterine contraceptive device

Abstract

A technical description of a Danish designed IUD the polygon (Antigon) is given and clinical experiences are related of its 2 years of use in Denmark. The polygon (Antigon) is formed as a frame 30 x 23 mm molded in 1 piece of high pressure polyethylene that does not give off deleterious substances. The polygon consists of 2 short straight sides which meet at an angle and form the top of the polygon and 2 rather longer straight sides each forming a right angle with the short sides while the bottom is semicircular. Bending always takes place at the angles. By compressing the lower sides the polygon assumes the shape of a probe so that it can be introduced easily through the cervical canal. A small powerful magnet is embedded in 1 of the longer sides for use in detecting the device. The polygon is easy to insert and is packed together with its own disposable inserter. Antigons inserted into 707 women over a period of 7200 months of observation resulted in 48 expulsions or an expulsion rate of 6.8%/100 woman-years. After reinsertions only a total of 12 patients discontinued using the the device because of expulsion. The polygon was removed in 10 cases because of menstraul disturbances and 6 patients asked to have the method discontinued after 1 year because they wanted to conceive. 6 patients wanted to have the polygon removed for other causes. 18 patients or 3%/100 woman-years became pregnant; in 12 cases the polygon was in place in the uterus while 6 were lost. Perforation of the uterus was not observed. Of 707 patients 40 discontinued using the method because of removal expulsion or unwanted pregnancy (6 further because of the wish of pregnancy). The polygon (Antigon) is considered a valuable method for preventing pregnancy. According to a note at the end of the article a few cases of intestinal strangulation following perforation of an IUD of closed type have been reported since this work was submitted. A modification of the Antigon has been constructed.