Changes in Intrauterine Device Position From Initial Insertion to Check Up

There is some evidence of intrauterine contraceptive devices (IUDs) migrating after insertion; however, these studies had small sample sizes and have not been performed with an Australian population. Furthermore, current guidelines for IUDs provide ambiguous recommendations for post-procedure check-ups 5-8 weeks after insertion. In some cases, it is unclear if a pelvic ultrasound should be used to ascertain IUD position. The clinical usefulness of ultrasound as the primary post-procedure investigation has not been fully elucidated, nor has the migration and position change in an Australian population.

To evaluate the migration or change in position of IUDs in an Australian population, and the clinical usefulness of a post-procedure check with an ultrasound following insertion.

A retrospective cohort study over 3 years across eight Sydney sites by multiple practitioners.

645 cases were referred for insertion or IUD exchange under ultrasound. In 5% of cases the device was sub-optimally positioned at the time of insertion. On post-procedure follow-up, of the IUDs in the optimal position, 98.5% remained unchanged. 1.3% changed to a suboptimal position, but of these 75% had an underlying uterine anomaly. Of the devices that were sub-optimally positioned at time of insertion, 84% migrated to the optimal fundal position; those unchanged from suboptimal (16%) had anomalies or other causes identified.

Once an IUD is inserted into an appropriate position in the fundus, it is extremely unlikely to change position unless the patient has an underlying structural anomaly or a previous hysterotomy. Fundal positioning at the initial insertion was 95%, which on post-procedure check-up improved to 98.7% of cases. Reassuringly, of the IUDs which were sub-optimally positioned, 84% improved their position to an appropriate location 5-8 weeks later. This also suggests migration of devices into an optimal position. With this evidence that most IUDs will migrate to a more appropriate position, we suggest all guidelines remove the 4-8 week check, and that to perform an ultrasound only if symptomatic or if unable to palpate the IUD strings.

This study evaluates the migration or change in position of intrauterine contraception devices after initial insertion in an Australian population, and the clinical usefulness of a post-procedure check using ultrasound. The current Australian guidelines are not explicitly clear whether an ultrasound is required in post-procedure check-ups. This study demonstrates that an ultrasound is not a necessary component of post-procedure check-ups, as the vast majority of IUDs will migrate into an appropriate position over a two-month period following insertion.