The assessment of IUD mechanical resistance: an experimental model

An experimental model to assess IUD resistance to mechanical fatigue is presented by which the performance of several IUD models has been tested both new and after variable intrauterine use, up to 33 months. According to the results of this study, IUD resistance decreases exponentially with time, and IUD shape apparently affects resistance. Therefore, prolonged intrauterine use apparently increases rupture liability. Moreover, it is suggested that some IUD features can minimize chances of intrauterine rupture and/or fragmentation.