Background: 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.
Aim: 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.
Methods: A retrospective cohort study over 3 years across eight Sydney sites by multiple practitioners.
Results: 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.
Conclusion: 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.
Impact statement: 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.