Clinical characteristic and intraoperative findings of uterine perforation patients in using of intrauterine devices (IUDs)

Intrauterine devices (IUDs) are the most popular form of contraception used by millions of women worldwide, particularly in developing countries [1]. Currently, two major types of IUDs are used, the copper-releasing intrauterine device (IUD) and the levonorgestrel-releasing intrauterine system (LNG-IUS) [2, 3]. However, IUDs are not risk-free, and lots of complications have been reported, including expulsion, malpositioning, and uterine perforation [4]. Among them, the majority were missing the IUDs, and most of the missing IUDs were found in the uterus [2]; however, the device would also pass through the uterine serosa causing uterine perforation. Uterine perforation is rare, but it may cause serious problems, including pain, abnormal bleeding, bowel or bladder perforation, and fistula formation, when IUDs migrate into the pelvic peritoneal space invading the adjacent organs. Thus far, the invasion of omentum, pouch of Douglas, the serosa of the ileum, the bladder, and the rectum has been reported in patients with uterine perforation [3, 5–8]. The rate of uterine perforation was 0.3–2.6 in every 1000 users of copper IUD insertion, and the respective rate for LNG-IUS insertion was 0.3–2.2 [9–15]. Uterine perforation can be primary (at the time of insertion) or secondary (4 weeks or more after the insertion took place). Lots of risk factors were proposed for uterine perforation, including immediate post-partum period [10, 16], breastfeeding [14, 17], extremes of uterine posture [18], intrauterine device shape not fitting well with uterine cavity [19], inexperience of the inserter, and inappropriate technique during the IUD insertion [15, 16, 20].

Specifically, the use of intrauterine devices has been changing in parallel with social-economic development of China. In the 1980s, 90% of all IUDs were stainless steel rings; they were cheaper than copper T-shaped IUDs but were also less effective and had a greater rate of expulsion [1]. In the 1990s, the use switched to T-shaped copper IUDs, although a large population of women was still using the steel rings [21]. Today, there are dozens of different types of IUDs available on the market that clearly mirror their clinical application [22–24]. Most of the IUDs used in China are manufactured in China, and the majority is the copper-releasing IUDs, including all types of T-shaped and V-shaped copper-releasing IUDs. Recently, some overseas products, as LNG-IUS [25] and GyneFix [26], have also been introduced to China.

Although lots of factors have been proposed, the precise cause of uterine perforation is not well understood [27]. The risk factors associated with use of IUDs by Chinese women were not reported. In this retrospective study, we attempted to evaluate all potential risk factors for uterine perforation associated with the use of IUDs by Chinese women and provide suggestions possibly useful for the management of IUD migrations.

Uterine perforation is a serious complication associated with IUD use. The precise mechanism of induction of uterine perforation is not well understood. A lot of risk factors were proposed for the induction of uterine perforation [10, 14, 15, 19]. In this study, we found that the time of IUD insertion after the last delivery is shorter in the uterine perforation group when compared with the subjects without uterine perforation. A sharp increase of the uterine perforation rate occurred in the subjects with IUD inserted up to 6 months after delivery. The incidence of uterine perforation within the first 6 months was significantly higher when compared with the subjects treated under the same conditions but without uterine perforation (Table 1, 51.7 vs. 24.6%, p < 0.05). At this stage, most patients were still in the breastfeeding period, and all 15 subjects in the lactation period were diagnosed with uterine perforation. This finding is consistent with previous reports that women in the lactation period are at a high risk of uterine perforation [14, 17]. In addition, most of the patients with the uterine perforation had received an IUD at rural hospitals or a lower level of health care systems. Typically, the experience and technique of an obstetrician-gynecologist in rural hospitals or lower level health care systems are poorer when compared to those in urban hospitals in China. Many obstetrician-gynecologists in rural hospital or a lower level of health care systems are lacking an efficient training on handling of IUD insertion, which may directly cause perforation at the insertion time. As it was reported before, IUD migrations at the time of insertion may directly contribute to uterine perforation [14, 17, 28].

The IUD use in China has a long history, and it can be found as earlier as 1979 [1]; however, the IUD devices were still not well managed. In the early years, most IUDs were steel rings (designated as O-shaped in this study) due to its low cost, and the devices were provided free of charge in some hospitals [1, 22]. Later, the copper-releasing IUDs replaced the steel rings as many problems were encountered by using the rings [29].Nowadays, copper-releasing IUDs have become the prevailing devices in clinical application in China [22, 24]. Recently, the levonorgestrel intrauterine system (LNG-IUS) along with other optimized IUDs were also provided to Chinese women [25]. In this study, the majority of devices that induced uterine perforation were copper-releasing IUDs with T-shaped copper (n = 10) followed by V-shaped copper IUDs (n = 13) and four of those with O-shaped IUDs (Table 1). A larger number of patients is required to assess the risk factors associated with different types of IUDs, including the LNG-IUS that are used in China.

Pelvic adhesions as a consequence of uterine perforation also frequently occurred in the patients, but the mechanism is still unknown; it may due to different actions of the devices [3]. In our study, we found that 12 out of the 13 patients with V-shaped contraceptive intrauterine devices had pelvic adhesions (Fig. 1B). This is significantly higher when compared with the patients that used O-shaped IUDs. The reason(s) for the higher rate of pelvic adhesions in patients who used V-shaped IUD is unknown at present. This issue requires a thorough investigation.

If the IUDs were missing, a method of searching for the strings or IUDs in the uterine cavity is sweeping by using uterine forceps. However, there are many IUDs used by Chinese women that do not have any string [23] (Fig. 1). The exploration success rate highly varies and is dependent on the experience and applied technique by the obstetrician-gynecologist who removes the IUDs using forceps or hooked instruments [30]. Under these aggravating circumstances, hysteroscopy and/or laparoscopy are suggested procedures, which secure a very high success rate [6–8, 31]. If the IUDs migrated into the pelvic peritoneal cavity, the procedures become dubious. Currently, the WHO recommends that all misplaced IUDs should be surgically removed once they are identified [32]. Some researches, however, suggest that if the migrated IUDs do not cause serious complications or significant symptoms, their removal is not necessary [33, 34]. In our study, all displaced IUDs associated with uterine perforation were successfully removed using laparoscopy and/or hysteroscopy that was accompanied with significant complications. Laparoscopy and/or hysteroscopy provide a high success rate in the removal of migrated IUDs in the patients with uterine perforation.

Potential risk factors associated with IUD use for the uterine perforation in Chinese population of patients are identified in a retrospective observational study. Hysteroscopy and/or laparoscopy are effective approaches in removing of displaced IUDs. A tailored training program planned to meet patients’ needs in rural areas and at a lower level of health care system may be justified.