What are the symptoms of uterine perforation caused by modern copper intrauterine devices (Cu-IUDs) and the levonorgestrel-releasing intrauterine system (LNG-IUS); how is perforation detected and what are the findings in abdominal surgery?
Symptoms are mostly mild and ∼30% of women are asymptomatic. Surgical findings are mainly minimal; no visceral complications were found in this study. However, adhesions as well as pregnancies seem to be more common among women using Cu-IUDs.
Prior studies and case reports have suggested that uterine perforation by modern IUDs/IUSs is rarely serious.
A retrospective study of 75 patients (54 LNG-IUS and 21 Cu-IUD) treated surgically for uterine perforation between 1996 and 2009.
The patients treated for uterine perforation by an IUD/IUS at clinics of the Helsinki and Uusimaa Hospital District were identified using the National Care Register for Health Institutions in Finland. The clinical data were collected from individual patient records.
The majority of patients (n = 53; 71%) had mild symptoms of abnormal bleeding or abdominal pain or both, in combination with missing IUD/IUS threads. Asymptomatic patients (n = 22; 29%) were examined because of missing threads or pregnancy. Failure to remove the IUD/IUS by pulling visible threads was the reason for referral in seven women (9%) requesting removal of the device. Eleven women (15%) were pregnant. Misplaced IUDs/IUSs were localized by a combination of vaginal ultrasonography (US) and X-ray, hysteroscopy or curettage. Only after this were patients treated by means of laparoscopy. The majority (n = 44; 65%) of the 68 intra-abdominal devices were located in the omentum, the remaining 24 (35%) around the uterus. Partial perforation or myometrial embedding was diagnosed in all seven cases (9%) with visible threads, but unsuccessful removal by pulling. During laparoscopy, filmy adhesions were found in 21 patients (30%). Pregnancy (33 versus 7%, P = 0.009) and intra-abdominal adhesions (58 versus 20%, P = 0.002) were significantly more common in the Cu-IUD group. Infections were rare; one non-specific acute abdominal infection, later found to be unrelated to the IUD, led to laparoscopy and in four cases the IUD was surrounded by pus, but there were no symptoms of infection.
The study setting revealed only surgically treated symptomatic patients and asymptomatic women attending regular follow-up. Women not treated, but only followed or not attending follow-up, were not identified, excluding the possibility to analyse missed undiagnosed perforations, or conservative follow-up as a treatment option.
As surgical findings are minimal, asymptomatic women may need no treatment at all. An alternative form of contraception is, however, important as pregnancies do occur. If a woman plans a pregnancy, a misplaced LNG-IUS should be removed, as it may act as a contraceptive.