RESUMO
Objective To understand the situation of downward dislocation of intrauterine device (IUD) and the impact related to the effectiveness of IUD use, in China. Methods An epidemiological survey with cross-sectional, retrospective and prospective study designs was conducted to investigate 18 922 IUD users who were selected by a multi-phase stratified cluster sampling method. Results IUD's downward dislocation had been an important unsuccessful issue related to the IUD insertion that accounted for 20% of total the cases of failure. The top three failure outcomes would include extrusion,removal due to downward dislocation and unintended pregnancy. Respectively, the cumulative rates and the ranking due to IUD failure (per 100 women) in the first, third, sixth and twelfth month were shown as follows: extrusion appeared as 0.33%, 1.13%, 2.21% and 4.30%; removal as 0.10%, 0.37%, 0.80% and 2.34% ; while unintended pregnancy were 0.03%, 0.14%, 0.41% and 1.14%. Conclusion IUD' s downward dislocation made great impact on the effectiveness of IUD use that should call for attention from relative governmental sectors and researchers in the areas of prevention, diagnosis and treatment.