The reliability of the anchoring concept for suspension of bioactive substances in the human uterus evaluated by measuring the removal force: results after long-term use.

OBJECTIVE

The objective of the present study is to report on the force needed to remove the implanted GyneFix intrauterine contraceptive device (IUD) from the uterine cavity. This study is the first long-term study on the retrieval of the anchored IUD.

STUDY

DESIGN

A two-center, noncomparative study to measure the force needed to remove the IUD in 251 women. A dynamometer (Pesola, Switzerland) was used to measure the removal force in newtons.

RESULTS

The results of this study show a mean removal force of 6.2 and 6.1 newtons, respectively (range, 0-10), in parous and nulligravid or nulliparous women (p = 0.62). There was no difference in removal force for those women with a duration of use either less than 60 months or longer than 60 months (median of 6 newtons in both groups; p = 0.22).

CONCLUSIONS

The force needed to remove the GyneFix IUD suggests that the implantation technology used in the insertion of the device is reliable, provided the anchoring knot is properly inserted in the fundal myometrium. The results of this study indicate that early expulsion of the device could be explained by failure to implant the knot adequately (no implantation or partial implantation), which requires a degree of skill. The present study does not provide an explanation for the occurrence of late expulsion, although some speculations can be made.