Perforation risk and intra-uterine devices: results of the EURAS-IUD 5-year extension study

The objective of this analysis was to identify intra-uterine devices (IUD) perforations detected from 12 to 60 months following IUD insertion, and to combine this information with (our previously published) data about perforations detected in the first 12 months to calculate cumulative perforation rates.

Prospective, non-interventional cohort study with new users of levonorgestrel-releasing intra-uterine systems (LNG-IUS) and copper-IUD. The original cohort included 61,448 women followed for 12 months. Of these, we had sufficient resources to perform an additional follow-up and analysis at 60 months in 39,009 women. Inclusion criteria for this analysis was insertion prior to 31 July 2010. All potential cases were validated via the health care professional or medical records. Crude and adjusted relative risks were calculated using a logistic regression model.

We identified 23 additional perforations (19 LNG-IUS and 4 copper-IUD) more than 12 months after insertion. Added to perforations detected at 12 months, the overall perforation rate was 2.1 per 1000 insertions (95% CI: 1.6-2.8) for LNG-IUS users (40 + 19 perforations/27,630 insertions) and 1.6 per 1000 insertions (95% CI: 0.9-2.5) for copper-IUD users (14 + 4 perforations/11,379 insertions). LNG-IUS users had a borderline higher risk of perforation compared with copper-IUD users (ORadj 1.7; 95% CI: 1.0-2.8). Forty-five (58%) of the 77 perforations were associated with suspected risk factors. Breastfeeding (RR 4.9, 95% CI: 3.0-7.8) and time since delivery (RR 3.0, CI: 1.5-5.4) remained significant risk factors in perforations detected after 12 months. No perforations resulted in serious injury to intra-abdominal or pelvic structures.

The incidence of uterine perforations in this study was low, although higher than the commonly reported rate. Approximately one third of perforations are detected 12 months after insertion. Clinical sequalae of perforations are generally mild and associated with a very low risk of injury to intra-abdominal and pelvic structures. Implications Uterine perforation is a rare risk associated with intra-uterine device use. Late diagnosed perforations can occur, although women can be reassured that the morbidity associated with detection and removal is low.