Among the 820 million married women of reproductive age who used any contraception in 2020, nearly half used permanent and long-acting methods (48 per cent), including female sterilisation (25 per cent) and IUDs (19 per cent). The total number of current IUD users has reached an estimated 161 million women worldwide [3].

The IUD might be considered the contraceptive method of choice for married women. There are two types of IUD: a copper IUD and a hormonal levonorgestrel device. Typical complications of both types include unsuccessful insertion, discomfort, vasovagal responses, infection, period irregularities, and expulsion. Although uncommon, uterine embedment (where the IUD is situated in the myometrium) and perforation (where any or the entire IUD is located beyond the uterine serosa) occur in approximately one of each 1000 insertions [4].

Known risk factors for uterine perforation include inadequate family planning provider training, insertion during the early puerperal phase when the uterus is fragile and bulky, a history of perforation, and an anatomically highly flexed uterus [5].

An IUD migrates because of a traumatic initial perforation of the uterus or a long-term inflammatory disease whose exact cause is unknown. Copper in some IUDs can cause an inflammatory response that results in the contraceptive effect, but it can also be involved in the process of long-term uterine perforation and transmigration [6]. It should be noted that our 3 patients wore copper-type IUDs.

But a large prospective non-interventional comparative cohort study of IUD users (N=61,448 women) revealed no significant difference in uterine perforation risk between hormonal and copper IUDs. Breastfeeding and proximity to a recent delivery (up to 36 weeks) were independently related with an increased risk of uterine perforation. The combination of these two factors was associated with an additive increase.

A migrating IUD's complications are mostly determined by where it ends up. A literature review of the 18 years until 1999 found 165 documented cases distributed at the following sites: the omentum (27%), the rectosigmoid (26%), the peritoneum (24%), the appendix (0.05%), the small bowel (0.01%), the adnexa, and the iliac vein (0.006%), migration to the bladder is unusual, with only 31 cases reported even though the bladder is very close to the uterus [1]. Reports of migrating IUDs causing ureteric erosion [7]and rectal perforation [8] have also been documented.

The interval between insertion and symptoms varies from 6 months to 16 years [9].

Bjornerem shows that IUDs can migrate to the bladder in a short amount of time. He described a case in which the patient had trouble of IUD. Lower abdominal pain and pollakiuria appears one week after IUD implantation. Three weeks later, cystoscopy confirmed that the IUD had been fully transported to the bladder, with intact bladder mucosa and no evidence of perforation. After migrating through the bladder wall, it frequently causes bladder irritation symptoms, and stones accumulate slowly over time. Its most common symptoms are frequent urination, urgency, dysuria, haematuria, and lower abdomen pain. [10]. These symptoms have been seen in each of our cases but very lately after the IUD placement.

It is unclear when the IUD migrated to the bladder: after insertion, intercourse, heavy work, or for unexplained reasons The transmigration of foreign bodies between organs is a highly intricate and challenging process to comprehend [11].

Regular follow-ups are therefore highly suggested for the early detection of IUD migration and the prevention of its consequences. The cause of this patients IUD migration was unknown, and they did not return for follow-up.

As recommended by the Moroccan ministry of health population department (family planning division), the first check should be performed four to six weeks after the insertion. Then, regular checks every 6 months aim to re-examine the patient outside of the rules to confirm the presence of IUD, ensure acceptance, and identify and treat secondary effects [12].

The IUD is usually removed in a consultation at the patient's request if she wishes to become pregnant, if the IUD is poorly tolerated or when the period of use has expired (Copper IUDs can last for as long as 10 years, while hormonal IUDs can be effective for three to eight years depending on the brand and type).

The majority of our patients did not comply with the follow-up, were not offered any change or removal of the IUD and mistakenly believed that the IUD had been expulsed. These three factors are what we believe to be the main risk factors associated with this complication.

The common rule is that any woman who complains of lower urinary tract issues with a notion that an IUD has been placed but not found or incorrectly presumed to have been expulsed is experiencing an intravesical migration of the IUD until the contrary is proved.

More than 50% of the published study including patients with IUD migration to the bladder have presented with stones ranging in size from 1 to 10 cm. It’s because the foreign bodies in the bladder cavity act as a nidus for stone formation, and infections may also be risk factors (urea-splitting organisms such as Proteus, Klebsiella, Serratia, and Enterobacter species produces alkaline urine, which promotes formation of struvite stones) [13]. It should be noted that all our patients were treated for undocumented recurrent urinary tract infections, which delayed the diagnosis.

Imaging plays a crucial role in the management of patients with migration IUDs. Ultrasonography is the most common initial method of evaluation due to its cost-effectiveness, lack of ionizing radiation, and greater detail of pelvic anatomy. The stem is usually easily identified on standard two-dimensional (2D) transvaginal ultrasonography (TVUS) as a linear echogenic structure. While the arms of the copper IUD are also fully echogenic, the arms of the levonorgestrel-releasing IUD are only echogenic at the proximal and distal ends, with characteristic central posterior acoustic shadowing on transverse images. Three-dimensional (3D) reconstructions are increasingly being used, particularly in the coronal view, which allows for a more careful evaluation of the arm positioning. When the IUD cannot be seen on pelvic ultrasonography, abdominal radiographs can be used to evaluate IUD positioning, as all IUDs are radiopaque. Positioning on an abdominal radiograph varies with normal uterine positions, but the IUD should be located near the midline low in the pelvis and orientated with the arms superior to the stem. In cases where complications such as perforations or abscesses are suspected, computed tomography (CT) or magnetic resonance imaging (MRI) may be a helpful adjunctive modality given their larger field of view. Of note, both copper and hormone-releasing devices are considered safe for up to 3-T MRI [14]. In all of our patients, the diagnosis was made during exploration.

Cystoscopic or suprapubic cystoscopic removal of the device and stones can be useful for IUDs that are fully inside the bladder or that develop small calculi [15]. Open surgery has usually been performed to remove IUDs that have formed large stones or with partial penetration of the bladder wall [16,17].

However, open surgery entails increased patient morbidity. Laparoscopy can be a less invasive option than an open surgical procedure [18].