Fracture and chemical composition of the deposit formed on the Lippes loop after prolonged use.

In order to confirm or refute the theory that there is the need to replace IUD's every few years due to their breaking, 26 Lippes Loops were tested. The sediment found on the devices was composed mainly of calcium carbonate. After removal of the sedimentation, it was seen that there was some corrosion of the body of the devices which caused a decrease in the IUD thickness. Pressure tests showed that an IUD which has been in use for a long period of time is more rigid, has less ability to deform and breaks under less pressure. It seems that the current medical opinion stating that IUD's should be replaced every few years, is valid.