Asymptomatic uterine perforation and IUD migration to the broad ligament: A case report.

RATIONALE: Uterine perforation is a serious complication of intrauterine contraceptive device (IUD) placement. However, as complete uterine perforation and extrauterine migration may remain asymptomatic, thorough localization of the IUD is important prior to reinsertion. PATIENT CONCERNS: A 33-year-old patient who has had 4 IUD insertions, wherein the location of the first IUD (inserted 14 years ago) was not identified prior to reinsertion and replacement of the subsequent three. She presented to hospital with a 6-month history of abdominal pain. Pelvic ultrasonography (US), radiography, hysteroscopy and laparoscopy examinations confirmed that a retained migrated IUD in the right broad ligament. DIAGNOSIS: Uterine perforation, IUD migration to the broad ligament. INTERVENTIONS: The patient underwent hysteroscopy and laparoscopy. OUTCOMES: Both IUDs were successfully removed without any complications.

Hysteroscopic Lysis of Complex Uterine Adhesions After Interventional Radiology-Guided Access.

OBJECTIVE: To demonstrate a novel surgical technique using hysteroscopic lysis of adhesions after interventional radiology (IR)-guided access in patients with severe intrauterine adhesions and challenging uterine access. DESIGN: This video illustrates the technique of the safe division of intrauterine adhesions after IR-guided access. SETTING: Conventional hysteroscopic adhesiolysis might be inadequate or risky in cases of severely narrowed or obstructed uterine flow tract, possibly resulting in incomplete adhesiolysis, false passages, or uterine perforation. This video presents 2 cases from a tertiary center involving a multidisciplinary team of a reproductive surgeon and an interventional radiologist. The first case involves a 38-year-old with severe Asherman syndrome, who experienced unsuccessful attempt to treat adhesions that was complicated by a false passage. The second case involves a 39-year-old with recurrent severe Asherman syndrome and a history of unsuccessful attempts at hysterosalpingogram and conventional hysteroscopic lysis of adhesions. INTERVENTIONS: In the IR suite, the patient was put in a lithotomy position on the fluoroscopy table. A vaginal speculum was inserted exposing the cervix. The procedure was performed using intravenous sedation and topical anesthetic spray applied to the cervix. Using fluoroscopy, a balloon cannula was inserted through the cervix, followed by contrast injection to assess uterine access. If there is no route, transvaginal ultrasound-guided needle cannulation of the main portion of the uterine cavity would be performed, approximating as closely as possible to the expected route of the cervical canal. A guidewire followed by a locked loop catheter was advanced through adhesions into the uterine cavity. The catheter was left protruding from the cervix to guide the hysteroscope. The patient was then transferred to the operating room for the hysteroscopic procedure. Under the guidance of the intrauterine catheter, the adhesions were carefully lysed using cold scissors. The endometrial cavity and tubal openings were inspected to ensure complete adhesiolysis and exclusion of any other copathologies. CONCLUSION: IR guidance can provide a safe and effective approach to hysteroscopic lysis of adhesions in patients with challenging intrauterine adhesions and difficult uterine access, such as patients with severe Asherman syndrome, intractable cervical stenosis, uterine wall agglutination, previous adhesiolysis failure, marked fixed retroverted retroflexed uteri, and previous false passage or uterine perforation.

Descriptive study of the real-world, long-term cost estimates and duration of use for hormonal and nonhormonal intrauterine devices using US commercial insurance claims.

BACKGROUND: Intrauterine devices (IUDs) have comparable efficacy to permanent surgical contraceptive methods; however, long-term costs are infrequently considered. Existing estimates inconsistently account for costs outside of IUD insertion or removal, actual duration of use, or differences between hormonal and nonhormonal IUDs. OBJECTIVE: To describe health care resource utilization and commercial payer costs that arise throughout hormonal and nonhormonal IUD use. METHODS: In this retrospective cohort study, paid claims data (Merative, MarketScan) from a large US commercial claims database were evaluated between 2013 and 2019. Claims were included from individuals aged 12 to 45 years who had an IUD inserted in 2014, continuous insurance coverage for 1 year prior to insertion and throughout follow-up, and no insertion, removal, or reinsertion in the previous year. Procedures and services that could be IUD-related were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Edition codes. Duration of IUD use was evaluated by Kaplan-Meier analysis of time to IUD removal. Event rates were determined for identified procedures and services; costs were calculated as the sum of payer reimbursements per enrolled individual. All IUD types available during the study period were described: 2 hormonal IUDs (52-mg and 13.5-mg levonorgestrel-releasing [LNG]) and the nonhormonal (380-mm2 copper) IUD. RESULTS: Of 195,009 individuals meeting the age requirement and receiving an IUD in 2014, 63,386 met the inclusion criteria and 53,744 had their IUD type on record-42,777 (67.5%) 52-mg LNG, 2,932 (4.6%) 13.5-mg LNG, and 8,035 (12.7%) nonhormonal IUD users. Despite differences in their indicated duration (13.5-mg LNG, 3 years; 52-mg LNG, 5 years; and nonhormonal, 10 years), most individuals had their IUD removed before its indicated full duration of use (13.5-mg LNG, 56.1%; 52-mg LNG, 61.3%; nonhormonal [at 5 years], 54.6%). The event rate per 100 individuals during the follow-up period was highest for abnormal uterine bleeding (16.2), ovarian cysts (9.3), and surgical management of uterine perforations (4.5). IUD insertion costs (mean ± SE) per enrolled individual for the 13.5-mg LNG, 52-mg LNG, and nonhormonal IUDs were $931 ± $9, $1,107 ± $4, and $897 ± $6, respectively. Cumulative mean ± SE 5-year postinsertion costs for the 13.5-mg LNG, 52-mg LNG, and nonhormonal IUDs were $2,892 ± $232, $1,514 ± $31, and $1,389 ± $97, respectively, among the remaining enrolled individuals. CONCLUSIONS: In this descriptive study of commercially insured IUD users, at least half had their IUD removed before its indicated duration. IUD improvements that reduce the frequency of abnormal uterine bleeding, ovarian cysts, and uterine perforations may help reduce long-term IUD costs.

Coincidental spontaneous perforation of the small intestine following operative hysteroscopy: A case report.

OBJECTIVE: Operative hysteroscopy is a common gynecologic procedure, but it carries the risk of complications. Spontaneous small intestine perforation is rare and fatal, especially in young adults. We present a spontaneous small intestine perforation after operative hysteroscopy with mimicking sign of uterine perforation after operation hysteroscopy. CASE REPORT: A 30-year-old nulligravida woman underwent Truclear® hysteroscopic polypectomy in the morning in LMD. She suffered from upper abdominal pain in the afternoon. Subsequently, progressive abdominal distention and imminent shock occurred the next morning. Initially, it was supposed to be a case of uterine rupture with internal bleeding. She was transferred to the emergency department of our hospital. Complete biochemistry data and abdominal CT were performed. The CT revealed pneumoperitoneum and ascites. Emergent laparoscopy was arranged. The abdominal cavity was full of intestinal fluid and the myomatous uterus was intact. The surgeon performed a laparotomy, two sites of spontaneous perforation of the small intestine were detected. The patient underwent laparotomic segmental resection and anastomosis and was discharged 14 days after surgery without incident. CONCLUSIONS: The risk of uterine perforation during hysteroscopy is up to 1.6%. The use of non-thermal intrauterine morcellator device (Truclear®) has been shown to significantly reduce the risk of perforation and thermal injury. As this case highlights, we suspected the possibility of uterine perforation immediately after hysteroscopic surgery. However, it happened to be rare spontaneous perforation of small bowel. The patient recovered well after timely transfer and management. Hysteroscopy is a very common procedure in gynecologic clinics, but even relatively safe intrauterine morcellator devices carry risk of complications. As a healthcare provider, we should beware of any comorbidity, for sometimes it would be catastrophic.

Outpatient hysteroscopic removal of retained products of conception: evaluation of effectiveness, safety and patient satisfaction.

OBJECTIVE: To assess effectiveness, safety and patient satisfaction of hysteroscopic removal of retained products of conception using a tissue removal system in the outpatient setting. STUDY DESIGN: A prospective observational study was carried out in a tertiary care hospital over a 10-month period. Fifty-two women who underwent an outpatient hysteroscopy for removal of retained products of conception were included. Effectiveness was evaluated as complete removal of retained products of conception in a one-time procedure. Safety was determined based on the rate of complications using the Clavien-Dindo classification system. Patient satisfaction and pain were assessed using a visual analogue scale survey completed by patients after the procedure. RESULTS: Complete removal of retained products of conception in a one-time procedure was achieved in 98.1% of cases. The mean morcellation time was 6.0 min. The complication rate recorded in this study was 9.6%; most complications were mild, but there was one case of uterine perforation. A global satisfaction ratio of 8.9 out of 10 was reported by patients. The study did not find any significant differences in complete removal of retained products of conception based on type of hysteroscope, presence of symptoms or Gutenberg classification. Although not significant, a linear relationship was observed between a higher volume of retained products of conception and a higher Gutenberg classification (p=0.229). CONCLUSION: Outpatient management of retained products of conception using a tissue removal system is effective and safe, and has a high level of patient satisfaction. The results of this study have the potential to alter the standard approach to the management of retained products of conception.

Risks of Uterine Perforation and Expulsion Associated With Intrauterine Devices.

OBJECTIVE: The APEX-IUD (Association of Perforation and Expulsion of Intrauterine Devices) study evaluated the association of postpartum timing of intrauterine device (IUD) insertion, breastfeeding, heavy menstrual bleeding, and IUD type (levonorgestrel-releasing vs copper) with risks of uterine perforation and IUD expulsion in usual clinical practice. We summarize the clinically important findings to inform counseling and shared decision making. METHODS: APEX-IUD was a real-world (using U.S. health care data) retrospective cohort study of individuals aged 50 years and younger with IUD insertions between 2001 and 2018 and with electronic health record data. Cumulative incidences of uterine perforation and IUD expulsion were calculated. Adjusted hazard ratios (aHRs) and 95% CIs were estimated from proportional hazards models with control of confounding. RESULTS: Among the study population of 326,658, absolute risk of uterine perforation was low overall (cumulative incidence, 0.21% [95% CI 0.19-0.23%] at 1 year and 0.61% [95% CI 0.56-0.66% at 5 years]) but was elevated for IUDs inserted during time intervals within 1 year postpartum, particularly among those between 4 days and 6 weeks postpartum (aHR 6.71, 95% CI 4.80-9.38), relative to nonpostpartum insertions. Among postpartum insertions, IUD expulsion risk was greatest for insertions in the immediate postpartum period (0-3 days after delivery) compared with nonpostpartum (aHR 5.34, 95% CI 4.47-6.39). Postpartum individuals who were breastfeeding had a slightly elevated risk of perforation and lowered risk of expulsion than those not breastfeeding. Among nonpostpartum individuals, those with a heavy menstrual bleeding diagnosis were at greater risk of expulsion than those without (aHR 2.84, 95% CI 2.66-3.03); heavy menstrual bleeding also was associated with a slightly elevated perforation risk. There was a slightly elevated perforation risk and slightly lower expulsion risk associated with levonorgestrel-releasing IUDs compared with copper IUDs. CONCLUSION: Absolute risk of adverse outcomes with IUD insertion is low. Clinicians should be aware of the differences in risks of uterine perforation and expulsion associated with IUD insertion during specific postpartum time periods and with a heavy menstrual bleeding diagnosis. This information should be incorporated into counseling and decision making for patients considering IUD insertion. FUNDING SOURCE: Bayer AG. CLINICAL TRIAL REGISTRATION: EU PAS register, EUPAS33461.

Intraperitoneally Retained Contraceptive Device After Uterine Perforation: A Case Report.

A 29-year-old parous woman with a history of a T-shaped copper intrauterine device (IUD) insertion presented 8 months later with a complaint of the contraceptive device being missing. Computed tomography with contrast turned out to be superior to the combined abdominal and pelvic X-ray and transvaginal ultrasound in providing the detailed extrauterine location of the device between the urinary bladder and uterus. A laparoscopy was successful in the atraumatic freeing of the IUD from omental and bladder adhesions, and in its final removal.

Intestinal obstruction in pregnancy-a rare presentation of uterine perforation.

BACKGROUND: Intestinal obstruction is an uncommon non-obstetric condition during pregnancy which may cause maternal and fetal mortality. Clinicians are confronted with challenges in diagnosis and treatment of intestinal obstruction due to the overlapping symptoms, concerns over radiological evaluation, and surgical risks. CASE PRESENTATION: We reported a 39-year old, gravida 7, para 2, woman who suffered from acute intestinal obstruction at 34 weeks of gestation. Ultrasonography and abdominal computed tomography were applied for intestinal obstruction diagnose. Conservative treatment was initially attempted. But following ultrasound found the absence of fluid in the amniotic sac and the patient showed no improvement in clinical symptoms. An emergency caesarean section was then performed. Intra-operative assessment showed dense adhesion between the left wall of uterus and omentum, descending colon, and sigmoid colon. After adhesion dialysis, uterine rupture with complete opening of the uterine wall at the site of left uterine cornua was found without active bleeding. The uterine rupture was then repaired. CONCLUSIONS: Although uncommon during pregnancy, clinical suspicion of bowel obstruction is necessary especially in women with a history of abdominal surgery. Surgical intervention is indicated when conservative therapy fails and when there are signs of abnormal fetal conditions and worsened symptoms.

Use of uterine manipulator and uterine perforation in minimally invasive endometrial cancer surgery.

OBJECTIVE: Safety of the uterine manipulator (UM) within endometrial cancer (EC) surgery is being questioned. Its use might be one of the issues for potential tumor dissemination during the procedure, especially in the case of uterine perforation (UP). No prospective data on this surgical complication, nor on the oncological consequences exist. The aim of this study was to assess the rate of UP while using UM when performing surgery for EC and the impact of UP on the choice of adjuvant treatment. METHODS: We conducted a prospective single-center cohort study from November 2018 to February 2022, considering all EC cases surgically treated by a minimally invasive approach with the help of a UM. Demographic, preoperative, postoperative and adjuvant treatment corresponding to the included patients were collected and comparatively analyzed according to the absence or presence of a UP. RESULTS: Of the 82 patients included in the study, 9 UPs (11%) occurred during surgery. There was no significant difference in demographics and disease characteristics at diagnosis that may have induced UP. The type of UM used or the approach (laparoscopic vs. robotic) did not influence the occurrence of UP (p = 0.44). No positive peritoneal cytology was found post hysterectomy. There was a statistically significantly higher rate of lymph-vascular space invasion within the perforation group, 67% vs. 25% in the no perforation group, p = 0.02. Two out of nine (22%) adjuvant therapies were changed because of UP. The median follow-up time for patients was 7.6 months (range 0.5-33.1 months). No recurrence was found in the UP group. CONCLUSION: Our study found a uterine perforation rate of 11%. This information needs to be further integrated to consider the usefulness of MU for EC surgery.

Complete perforated bladder from intrauterine devices: A case series report from a nationwide monitoring system.

AIM: Complete perforation of the bladder caused by an intrauterine device (IUD) is rare. This study examined the characteristics of patients associated with IUD-related bladder perforation and evaluated the relationship between mislocated IUDs and their potential complications. METHODS: From October 2005 to December 2021, 13 reports regarding complete perforations to the bladder by IUDs were retrieved from the National Contraceptives Adverse Reaction Monitoring System of China. The clinical features of these cases were analyzed. RESULTS: The median patient age was 30 (range, 27-46) years. There were four cases (4/13, 30.8%) with IUDs placed during lactation, one case (1/13, 7.7%) with an IUD placed after medical abortion, and eight cases (8/13, 61.5%) placed after menstruation. Seven cases (7/13, 53.9%) were first-time IUD users. The median duration of IUD placement was 47 (range, 1-145) months. Unexpected pregnancy was reported in five cases (5/13, 38.5%). Six cases (6/13, 46.2%) reported bladder stones with varying degrees of abdominal pain or urinary tract infection. Removal methods included laparotomy (four cases), cystoscopy (four cases), laparoscopy (two cases), laparoscopy combined with cystoscopy (two cases), and laparotomy after cystoscopy (one case). All IUDs were successfully removed. CONCLUSIONS: Complete perforation to the bladder by IUDs is a rare adverse event. Regular follow-up is required after the placement of IUDs. The possibility of uterine perforation should be investigated if IUD users encounter persistent lower abdominal pain or urinary tract infection.

Intraperitoneally displaced intrauterine device.

Intra-abdominal displacement of an intrauterine device (IUD) is a rare but serious complication. This is a case report of a 44-year-old woman who was referred to a surgical department with intermittent abdominal pain. Gynaecological examination and ultrasound failed to identify the patient's IUD. An abdominal CT scan confirmed the diagnosis of the intra-abdominally migrated IUD and the device was extracted by laparoscopy. Surgical removal of the migrating IUD is recommended to prevent long-term complications such as intra-abdominal adhesions, organ perforation, and fistula formation.

Hysteroscopic dilation techniques in hysteroscopic adhesiolysis. / é•œä¸‹æ‰©å®«æ³•åœ¨å®«è ”é•œå®«è ”ç²˜è¿žåˆ†ç¦»æœ¯ä¸­çš„åº”ç”¨.

OBJECTIVES: Intrauterine adhesion (IUA) is mainly caused by intrauterine operations such as pregnancy-related curettage and hysteroscopic surgery, resulting in the trauma to the basal layer of the endometrium. Hysteroscopic adhesiolysis is a crucial step in the comprehensive treatment of IUA, and the most common complication is uterine perforation. More than half of all uterine perforations occur during the hysteroscopy or probe/dilator pass through the internal os. Furthermore, inappropriate surgical procedures may lead to endometrial injury, recurrence or even aggravation of adhesions, and complications such as cervix laceration and false passage formation. This study aims to explore the usage of the hysteroscopic dilatation techniques to dilate the internal os and lower uterine segment, which is via hysteroscopy entering the internal os laterally and swinging, or by directly opening the forceps or scissors and bluntly spreading dissection under direct hysteroscopic vision. By using the hysteroscopic dilatation techniques, we intend to improve the effectiveness and safety of cervical dilation in patients with IUA in the internal os and/or lower uterine segment. METHODS: A total of 282 patients with adhesions in the internal os or lower uterine segment underwent HA in the Third Xiangya Hospital of Central South University from January 2020 to June 2021 were included, ranging from 21 to 46 (33.0±4.8) years old in age and 5 to 12 in the American Fertility Society score. Among them, there were 2 cases of false passage formation caused by traditional dilatation in other hospitals. All patients underwent hysteroscopy with integrated hysteroscopy with 5Fr instrument channel and 4.9 mm outer sheath diameter. The internal orifice of cervix and the lower segment of uterine cavity were dilated under the microscope. After the hysteroscopy entered the uterine cavity, the separation of uterine cavity adhesion and the placement of uterine contraceptive ring or uterine stent into the uterine cavity were performed routinely. Age, surgical records, and surgical videos of all included cases were collected. The success rate of dilation and the incidence of surgical complications were assessed. RESULTS: In all cases, the hysteroscopys successfully entered into the uterine cavity by using the hysteroscopic dilatation techniques without failure and switching to cervical dilators. In the 2 cases of false passage due to previous cervical dilation, the uterine cavity was identified and found successfully under direct hysteroscopic vision. During the whole surgery, the vision was clear, and no complications (such as cervix laceration, false passage formation, uterine perforation or water intoxication) occurred. One to 3 months postoperative hysteroscopy revealed no significant fibrotic stenosis in the internal os and lower uterine segment. CONCLUSIONS: The hysteroscopic dilation techniques are a strategy for separation methods that is following structural hierarchy anatomy in the mode of "see and treat" for the adhesion in the internal os and uterine cavity under direct hysteroscopic vision. This method not only has ultrasound guidance, but also has the judgment of structural hierarchy anatomy under direct hysteroscopic vision, so there is less chance of anatomical level judgment error. This method makes full use of the hysteroscopic judgement of the experienced hysteroscopic surgeons, so that surgeons can timely find and avoid re-entering the old false passage caused by previous surgery. The adhesions in the internal os and lower uterine segment were separated by the hysteroscopic dilation techniques. In this way, the damage to the endometrium caused by forced insertion of the hysteroscopy can be avoided. Meticulous separation of adhesions and cervical dilation under direct hysteroscopic vision can effectively reduce the occurrence of surgical complications such as false passage formation, cervical laceration, and uterine perforation. The use of mini-hysteroscopy eliminates the need for preoperative cervical preparation, avoiding associated risks and side effects. Moreover, for patients with adhesions in the internal os and lower uterine segment, preoperative cervical preparation is not effective in cervical dilation, while the hysteroscopic dilation techniques are effective, with higher patient acceptance due to the absence of preoperative cervical preparation. For the skilled hysteroscopic surgeons, the hysteroscopic dilation technique is easy to operate and worthy of clinical application.

[Endoscopic removal of intrauterine device perforating the sigmoid colon: case report]. / Retrait endoscopique d'un dispositif intra-utérin perforant le côlon sigmoïde: à propos d'un cas.

Intrauterine device (IUD) is the mainstay of family planning methods in developing countries. However, it is associated with severe complications such as bleeding, perforation and migration to adjacent organs. Although perforation of the uterus is not rare, migration to the sigmoid colon is exceptional. We here report a case of IUD migration into sigmoid colon; this was removed via low endoscopy. The study involved a 45-year-old woman using an IUD who presented with pelvic pain associated with a feeling of pelvic heaviness 6 years later of insertion. Clinical examination was without abnormalities, and computed tomography (CT) scan showed the IUD embedded in the sigmoid colon wall. Diagnostic and therapeutic laparoscopy was performed, which objectified IUD-related intestinal perforation. IUD was partially embedded in the sigmoid colon wall and couldn't be removed. The device was removed during colonoscopy by diathermy loop excision (15 mm in diameter).

Uterine perforation during intrauterine procedures and its management.

OBJECTIVE: Uterine perforation is a potential, not rare complication of all intrauterine procedures and may be associated with injury of surrounding organs and structures. The incidence, risk factors, possible prevention, dia-gnosis, management and impact on future reproduction is reviewed here. METHODS: Systematic review of available sources on the topic was carried out using the PubMed database and textbooks of Czech authors. CONCLUSION: Some risk factors that make access to the uterine cavity difficult may be prevented, however, others remain unpreventable. For patients in whom the perforation occurred during sondage, dilatation or insertion of blunt and cold instrument, without significant bleeding and who are hemodynamically stable, observation is recommended rather than immediate abdominal exploration. The exception are young women planning pregnancy in whom endoscopic suture is indicated. Abdominal exploration is required in patients who have been injured by electrosurgical or sharp device, laser, vacuum curette, who are hemodynamically unstable or show signs of severe bleeding or visceral injury.

Multiple uterine perforations during manual vacuum aspiration: the need to increase the clinical awareness of attending healthcare professionals.

Background: The risk of uterine perforation during manual vacuum aspiration (MVA) is reduced by using Karman cannula (which has a rounded tip) during the procedure. Methods: A 35-year-old multigravida at 13 gestational weeks presented with vaginal bleeding of a day duration and ultrasound evidence of retained products of conception suggestive of incomplete miscarriage. The patient was rhesus D positive and stable. She had MVA which was performed using Karman cannula, and developed severe vaginal bleeding. The differential diagnoses were incomplete uterine evacuation and uterine perforation. Results: During a laparotomy in Lloyd-Davies position, haemoperitoneum and six uterine perforations on the anterior and fundal parts, each approximately 5 mm in length (Figure 1), were found. The perforations were repaired and a check uterine curettage under oxytocic cover showed an empty uterus. The abdominal cavity was washed and closed. She was transfused three units of red blood cell concentrate and had a normal six weeks follow-up. Conclusion: When an instrument inserted into the uterus is pushed beyond the estimated depth of the uterus, a perforation must be suspected and the condition may be managed conservatively. A surgical procedure complicated by surgeon's loss of perception (in this case tactile) of tissues' anatomy is hazardous.

Intrauterine device-related uterine perforation incidence and risk (APEX-IUD): a large multisite cohort study.

BACKGROUND: Reports of perforation risk related to intrauterine devices (IUDs) inserted immediately post partum and among non-post-partum individuals are scarce, and previous studies with only 12-month follow-ups underestimate the risk. Breastfeeding at IUD insertion and insertion within 36 weeks post partum have been associated with increased risk of uterine perforation. The aim of these analyses was to compare the incidence and risks of IUD-related uterine perforations by non-post-partum and post-partum intervals at IUD insertion, and among post-partum individuals, to assess the impact of breastfeeding on these outcomes. METHODS: We did a multisite cohort study in the USA, using electronic health records (EHR). Study sites were three health-care systems and a site that used data from a health-care information exchange. The study population included individuals who were aged 50 years or younger and had an IUD insertion between Jan 1, 2001, and April 30, 2018. Individuals were excluded if they had not been in the health-care system for at least 12 months before IUD insertion. The primary outcome for this analysis was any IUD-related uterine perforation diagnosis for the first IUD insertion in this time period. Both complete and partial IUD-related perforations were identified. Chart abstraction was done to validate EHR-based algorithms or confirm perforations. The crude rate and cumulative incidence of uterine perforation were evaluated by non-post-partum and post-partum intervals at IUD insertion in the full cohort, and by breastfeeding status in a subcohort of post-partum individuals. Cox models estimated crude and adjusted hazard ratios (aHRs). FINDINGS: Data from 326 658 individuals in the full cohort and 94 817 individuals in the post-partum subcohort were analysed. In the full cohort, we identified 1008 uterine perforations (51·2% complete), with the 5-year cumulative incidence being the lowest in the non-post-partum group (0·29%, 95% CI 0·26-0·34). The aHR for the post-partum interval relative to non-post partum ranged from 2·73 (95% CI 1·33-5·63; 0 to 3 days post partum) to 6·71 (4·80-9·38; 4 days to ≤6 weeks post partum). The post-partum subcohort of individuals with breastfeeding information had 673 uterine perforations (62% complete), with a 5-year cumulative incidence of 1·37% (95% CI 1·24-1·52) and an increased risk with breastfeeding (aHR 1·37, 95% CI 1·12-1·66). INTERPRETATION: Although the risk for uterine perforation with IUD insertion 4 days to 6 weeks or less post partum is nearly seven times that of insertion non-post partum, perforation remains an incredibly rare event for all clinical time points. Despite a slight increased risk of perforation with breastfeeding at IUD insertion, the benefits of breastfeeding and effective contraception generally outweigh risks and should have little clinical impact. Therefore, IUD insertion timing should be based on individual desire for IUD contraception and patient convenience to assure an IUD insertion can occur. Careful follow-up of individuals at higher risk of uterine perforation is warranted. FUNDING: Bayer AG.