The use of vaginal ultrasound to identify copper T IUDs at high risk of expulsion

Conventional manual technique of post placental IUD insertion versus intra-cesarean post placental introducer withdrawal IUD insertion technique: a new standardized technique for IUD insertion during cesarean section: a randomized controlled trial

BACKGROUND

Inserting IUDs during cesarean section reduces the need for more manipulation and discomfort. The current conventional manual technique for IUD insertion during cesarean section is not standardized with many modifications and high rates of expulsion, displacement, missed threads, and discontinuation. This study aims to find a standard technique for IUD insertion during cesarean section with the least possible problems, especially displacement and missed threads.

METHODS

A randomized controlled study was conducted at Kasr Al-Ainy Maternity Hospital, Cairo University, Egypt. The study was performed over 12 months, from September 2020 to September 2021. Two groups of patients were selected; each group included 420 patients with a desire for IUD insertion during cesarean section. Group (A) (Control group) was subjected to a post-placental intrauterine device (Copper T380) during cesarean section using a conventional manual method; Group (B) (Study group): the IUD (Copper T380) was placed at the top of the uterine fundus using a new technique (intra-cesarean post placental introducer withdrawal IUD insertion technique).

RESULTS

There was a significant statistical difference between the two groups regarding displacement of the IUDs at the end of puerperium, at 6 months, non-visibility of IUD threads, and continuation of use with p-value < 0.05. There was no significant statistical difference in the term of duration of surgery.

CONCLUSION

The new technique of post-placental IUD insertion can be the standard technique of intra-cesarean section IUD insertion as it is associated with more favorable outcomes among the included women in the form of lower incidence of IUD displacement, non-visibility of IUD threads, and higher rates of continuation without increasing the duration of surgery as compared with the conventional manual technique.

TRIAL REGISTRATION

ClinicalTrial.gov ID: NCT05788354, registration date: 28/03/2023 (retrospectively registered).

Feasibility evaluation of a Zn-Cu alloy for intrauterine devices: In vitro and in vivo studies

The comprehensively adopted copper-containing intrauterine devices (Cu-IUDs) present typical adverse effects such as bleeding and pain at the initial stage of post-implantation. The replacement of Cu material is demanded. Zinc and its alloys, the emerging biodegradable materials, exhibited contraceptive effects since 1969. In this work, we evaluated the feasibility of bulk Zn alloys as IUD active material. Using pure Cu and pure Zn as control groups, we investigated the contraceptive performance of Zn-0.5Cu and Zn-1Cu alloys via in vitro and in vivo tests. The results showed that the main corrosion product of Zn-Cu alloys is ZnO from both in vitro and in vivo studies. CaZn₂(PO₄)₂·2H₂O is formed atop after long-term immersion in simulated uterine fluid, whereas CaCO₃ is generally formed atop after implantation in the rat uterine environment. The cytocompatibility of the Zn-1Cu alloy was significantly higher than that of the pure Zn and pure Cu to the human endometrial epithelial cell lines. Furthermore, the in vivo results showed that the Zn-1Cu alloy presented much improved histocompatibility, least damage and the fastest recovery on endometrium structure in comparison to pure Zn, Zn-0.5Cu and pure Cu. The systematic and comparing studies suggest that Zn-1Cu alloy can be considered as a possible candidate for IUD with great biochemical and biocompatible properties as well as high contraceptive effectiveness. STATEMENT OF SIGNIFICANCE: The existing adverse effects with the intrinsic properties of copper materials for copper-containing intrauterine devices (Cu-IUD) are of concerns in their employment. Such as burst release of cupric ions (Cu²⁺) at the initial stage of the Cu-IUD. Zinc and its alloys which have been emerging as a potential biodegradable material exhibited contraceptive effects since 1969. In this study, Zn-1Cu alloys displayed significantly improved biocompatibility with human uterus cells and a decreased inflammatory response within the uterus. Therefore, high antifertility efficacy of the Zn-1Cu alloy was well maintained, while the adverse effects are significantly eased, suggesting that the Zn-1Cu alloy is promising for IUD.

Uterine dimensions and intrauterine device malposition: can ultrasound predict displacement or expulsion before it happens?

OBJECTIVE

Intrauterine devices (IUDs) are the most commonly used method of long-acting reversible contraception. IUD malpositions are described as expulsion, embedding, displacement, and perforation, which may cause contraception failure, organ injury, hemorrhage, and infection. The aim of the study was to evaluate the relationship between displacement and IUD positioning in the uterus, and uterine dimensions as measured using transvaginal ultrasonography.

MATERIALS AND METHODS

Three-hundred and eighty-four patients who had TCu380A devices inserted at a tertiary hospital were evaluated at insertion and at 1 month, 3 months, and 6 months after insertion. At the insertion visit, demographic characteristics, history of menorrhagia, dysmenorrhea, previous IUD displacement, and obstetric history were recorded. Transvaginal ultrasonographic measurement of the uterine cavity, uterine length, uterine width, cervix length, cervix width, transverse diameter of the uterine cavity, the distance between the tip of the IUD and the fundus, and endometrium were measured to evaluate IUD displacement.

RESULTS

Sixteen of 384 patients had displacement. There were significant differences in times between last pregnancy outcomes and IUD insertion and dysmenorrhea history (p = 0.004 and p = 0.028, respectively). Among TCu380A users, women with 7.5 mm IUD endometrium distances had a higher risk for displacement with a sensitivity of 81% and specificity of 37.5% (AUC: 0.607, 95% CI 0.51-0.70). Women with uterus width less than 41.5 mm were more likely to have displacement with a sensitivity of 53.8% and a specificity of 75% (AUC: 0.673, 95% CI 0.60-0.75).

CONCLUSION

IUD endometrium distance and uterus width are important parameters for displacement for TCu380A.

Factors associated with low-lying intrauterine devices: a cross-sectional ultrasound study in a cohort of African-American women

OBJECTIVE

The object of this study is to examine factors and symptoms associated with low-lying IUDs as defined by ultrasound.

STUDY DESIGN

This is a cross-sectional sub-study of participants in the Study of Environment, Life-style, and Fibroids (SELF). SELF participants had screening ultrasounds for fibroids at study enrollment; those with an IUD in place are included in this sub-study. Low-lying IUDs were identified and localized. Logistic regression was used to identify factors and symptoms associated with low-lying IUDs.

RESULTS

Among 168 women with IUDs at ultrasound, 28 (17%) had a low-lying IUD. Having a low-lying IUD was associated with low education level (≤high school: aOR 3.1 95% CI 1.14-8.55) and with increased BMI (p=.002). Women with a low-lying IUD were more likely to report a "big problem" with dysmenorrhea (the highest option of the Likert scale) as compared to women with a normally-positioned IUD (OR 3.2 95% CI 1.07-9.54).

CONCLUSION

Our study found that women with a low-lying IUD are more likely to be of lower education and higher BMI, and to report more dysmenorrhea.

IMPLICATIONS

Women who are obese may benefit from additional counseling and closer follow-up after IUD placement. Future research is warranted to investigate IUD placement and possible IUD migration among women who are obese.

Three-dimensional versus two-dimensional ultrasound for assessing levonorgestrel intrauterine device location: A pilot study

PURPOSE

To compare the rates of success of two-dimensional (2D) and three-dimensional (3D) sonographic (US) examinations in locating and adequately visualizing levonorgestrel intrauterine devices (IUDs) and to explore factors associated with the unsuccessful viewing on 2D US.

METHODS

Transvaginal 2D and 3D US examinations were performed on all patients 1 month after insertion of levonorgestrel IUDs. The devices were considered adequately visualized on 2D US if both the vertical (shadow, upper and lower extremities) and the horizontal (two echogenic lines) shafts were identified. 3D volumes were also captured to assess the location of levonorgestrel IUDs on 3D US.

RESULTS

Thirty women were included. The rates of adequate device visualization were 40% on 2D US (95% confidence interval [CI], 24.6; 57.7) and 100% on 3D US (95% CI, 88.6; 100.0). The device was not adequately visualized in all six women who had a retroflexed uterus, but it was adequately visualized in 12 of the 24 women (50%) who had a nonretroflexed uterus (95% CI, -68.6; -6.8).

CONCLUSIONS

We found that 3D US is better than 2D US for locating and adequately visualizing levonorgestrel IUDs. Other well-designed studies with adequate power should be conducted to confirm this finding.

Expulsion and continuation rates after postabortion insertion of framed IUDs versus frameless IUDs - review of the literature

BACKGROUND

Early intrauterine device (IUD) discontinuation after insertion immediately following aspiration abortion or after early medical abortion occurs as a consequence of expulsion of the IUD or removal due to side effects. These are often the consequence of the uterine forces impacting on the IUD due to spatial discrepancy with the uterine cavity causing pain, abnormal bleeding, and eventually, removal of the IUD. These women are candidates for repeat pregnancy as they often select less-effective methods or no contraception at all. Repeat abortion could be reduced by giving attention to these factors.

STUDY DESIGN

In order to have an indication on the magnitude of the problem of IUD expulsion or discontinuation, we searched the MEDLINE database for clinical trials, randomized controlled trials, and prospective observational studies related to immediate postaspiration termination of pregnancy (TOP) and early medical abortion IUD insertion studies that reported IUD expulsion and IUD continuation rates.

RESULTS

The search identified 17 clinical trials that were suitable based on the data they presented. The majority concerned T-shape IUDs, inserted immediately following surgical (aspiration) pregnancy termination. Two studies were conducted after medical TOP, and four studies were conducted with the frameless IUD inserted after surgical (vacuum aspiration) TOP. The results showed expulsion rates between 0.8% and 17.3% at 8 weeks, up to 5 years after insertion, respectively. In four studies with the frameless IUD, totaling 553 insertions, the expulsion rate was 0.0% in three of them. Follow-up in the latter studies varied between 5 weeks and 54 months. Reported continuation rates with conventional (framed) IUDs were between 33.8% and 80% at 1 year for studies providing 1 year rates and between 68% and 94.1% for studies reporting continuation rates at 6 months. Studies utilizing frameless IUDs reported 1 year continuation rate over 95%.

CONCLUSION

Frameless IUDs, due to their attachment to the uterine fundus, appear to be better retained by the postabortal uterus when compared with conventional framed IUDs. The absence of a frame ensures compatibility with uterine cavity anatomical dimensions, and may therefore result in improved acceptability and continuation rates in comparison with framed IUDs. Both these characteristics of the frameless IUD could help reduce the number of repeat unwanted pregnancies and subsequent abortions in some cases.

Ultrasonography of intrauterine devices

The intrauterine device (IUD) is gaining popularity as a reversible form of contraception. Ultrasonography serves as first-line imaging for the evaluation of IUD position in patients with pelvic pain, abnormal bleeding, or absent retrieval strings. This review highlights the imaging of both properly positioned and malpositioned IUDs. The problems associated with malpositioned IUDs include expulsion, displacement, embedment, and perforation. Management considerations depend on the severity of the malposition and the presence or absence of symptoms. Three-dimensional ultrasonography has proven to be more sensitive in the evaluation of more subtle findings of malposition, particularly side-arm embedment. Familiarity with the ultrasonographic features of properly positioned and malpositioned IUDs is essential.

Intrauterine device quo vadis? Why intrauterine device use should be revisited particularly in nulliparous women?

Background

Long-acting reversible contraceptive (LARC) methods, including intrauterine devices (IUDs) and the contraceptive implant, are considered the best methods for preventing unintended pregnancies, rapid repeat pregnancy, and abortion in young women. An opinion paper of 2012 by the American College of Obstetricians and Gynecologists recommends Mirena and Paragard for use in nulliparous and adolescent women. However, these IUDs are not designed for young women and are not optimal as they often lead to early discontinuation.

Objective

This article was written with the objective to respond to the urgent need to improve intrauterine contraception as it is likely that the objectives of LARC will not be met without significant improvement of IUD design. Anatomical variations in size and shape of the uterus are not sufficiently considered, producing harm and suffering, which often lead to early removal of the IUD.

Proposed problem solving

The article describes why IUDs should be revisited to meet the challenge of LARC and proposes how to solve these problems. The opinion statement presented here may be considered provocative but is based on hundreds of women with IUD problems who consult or are referred to the practices of the authors of this article due to the disproportion between the IUD and their small uterine cavity. The solution is simple but requires a revision of the current design of IUDs. One-dimensional (longitudinal) IUDs are likely to be the first option. Framed devices with shortened transverse arm and IUDs which adapt to the width of the given uterus are viewed as second best.

Conclusion

One of the reasons of the high unintended pregnancy rate in the USA may be the paucity of suitable IUDs. Also, the legal climate in the USA seems to be a problem for developers as many lawsuits have recently been reported. Clinical studies conducted in young nulliparous and adolescent women suggest that IUDs that fit well in the uterine cavity, like a shoe, result in better tolerance, less side effects, and last but not least, higher use continuation rates.

Association of the Position of the Copper T 380A as Determined by the Ultrasonography Following its Insertion in the Immediate Postpartum Period with the Subsequent Complications: An Observational Study

PURPOSE

Incorrectly placed copper T 380A leads to increased contraception failure. This study aimed to find an association between the ultrasonographic position of the copper T 380A in the immediate postpartum period and the adverse effects observed during the period of 6 months after its insertion.

METHODS

This descriptive study was carried out in the Department of Obstetrics & Gynaecology of a tertiary-care-center of India from September 2011 to February 2013. The women eligible for immediate postpartum copper T 380A insertion with previous regular menstrual cycles for at least 6 months before the current pregnancy, and those who were willing for follow-up visits and had easy accessibility to the hospital, were recruited. A clinical evaluation and ultrasonographic assessment of Intra-Uterine-Contraceptive-Device (IUCD) after insertion was carried out after enrolment. The complications (expulsions, vaginal discharge, menstrual irregularity, and lower abdominal pain) were subsequently assessed during a 6-month follow-up period. The primary objective was the ultrasonographic assessment of the placement of IUCD immediately after insertion. The incidence of complications and their association with the presence of malposition was also studied.

RESULTS

Hundred patients were evaluated during the study period. Forty-four (44 %) women were found to have malpositioned IUCDs on ultrasonographic evaluation done following insertion. The complications among the IUCD users included menstrual irregularity (27.17 %), pain in lower abdomen (20.65 %), vaginal discharge (7.6 %), and expulsions (9.7 %). The IUCD expulsions, menstrual irregularities, and pain were significantly more in patients with malpositions (p < 0.05).

CONCLUSIONS

Malpositioning of IUCD is common immediately following insertion and is significantly associated with more complications during the follow-up.

[Diagnosis and management of uterine perforations after intrauterine device insertion: a report of 11 cases]

OBJECTIVE

Intrauterine device insertion is common. It is however not harmless and uterine perforation can be serious.

PATIENTS AND METHODS

Eleven cases of uterine perforation after intrauterine device insertion were listed at Tourcoing hospital between 2005 and 2009. They were analyzed to identify risk factors of uterine perforation and specify management.

RESULTS

The main symptom was pelvic pain (4 cases), pregnancy occurrence (3 cases) or inability to remove the IUD (2 cases). The intrauterine device was set during the first 9 months of post-partum in 7 cases, 2 patients were still breastfeeding. Seven patients underwent laparoscopy, 2 needed switch for laparotomy, one was treated by laparotomy only and one was lost of follow-up.

DISCUSSION AND CONCLUSION

Incidence of uterine perforation after IUD insertion ranges from 0,1 to 3/1000. Pelvic pain is the most revealing symptom. Fifteen percent of perforations complicate with adjacent organ lesion. Perforation incidence seems greater if the intrauterine device is set during the 6 first weeks of post-partum and breastfeeding, but non influenced by operator practical experience. Ultrasound follow-up of patients carrying intrauterine device is controversial. Facing a suspicion of ectopic intrauterine device, pelvic ultrasound examination is the first step imaging modality and using 3D could be useful. If it fails to localize the intrauterine device, an abdominal X-ray must be performed. Ectopic intrauterine device removal is recommended.

Length of the endometrial cavity as measured by uterine sounding and ultrasonography in women of different parities

BACKGROUND

In view of current controversies regarding the need for new, shorter intrauterine devices (IUDs) that would reduce expulsion rates in nulligravida, endometrial cavity length was measured in women of different parities using uterine sounding and ultrasonography.

STUDY DESIGN

A cross-sectional descriptive study was performed including 570 women of 17-52 years of age, 260 of whom were nulligravida and 310 parous.

RESULTS

The difference in mean length between measurements taken by uterine sounding and ultrasonography was 0.28 cm. Mean endometrial cavity length was 3.84+/-0.03 cm (mean+/-S.E.M.) in nulligravida and 4.25+/-0.03 cm in parous women according to uterine sounding (p<.001) and 3.70+/-0.03 cm and 3.84+/-0.03 cm, respectively, according to ultrasonography (p=.006).

CONCLUSIONS

By either technique, mean length of the endometrial cavity was >3.6 cm, the length of the most common IUDs, the TCu380A and the levonorgestrel-releasing intrauterine system. Therefore, the issue appears controversial for developing new, shorter IUDs, since current models fit most women, including nulligravida, albeit one third of the women of our sample showed endometrial length shorter than 3.2 cm.

Use of Volume Imaging in the Evaluation of Intrauterine Contraceptive Devices

Intrauterine contraceptive devices (IUD) have been a form of birth control for many hundreds of years. Just as their composition and architectures have changed, so have their sonographic appearances and clinical implications. With the emergence of volume imaging brings the ability to consistently evaluate the uterus in the coronal plane, which brings an entirely different diagnostic perspective and thought process for the evaluation of an IUD. This article provides three examples of how volume imaging is extending the sonographic evaluation of patients with IUDs.

Partial and complete expulsion of the Multiload 375 IUD and the levonorgestrel-releasing IUD after correct insertion

OBJECTIVE

The contraceptive efficacy of intrauterine devices (IUD) is thought to relate to the position of the IUD in the uterine cavity. Several trials examined the number of copper IUD expulsions, but none evaluated the partial and complete expulsion rate of the levonorgestrel-releasing device (LNG-IUD).

STUDY DESIGN

This retrospective cohort study compares the dislocation rate of the Multiload 375 IUD (ML 375) and the LNG-IUD in 214 women (107 subjects with each IUD). Transvaginal ultrasound was used to monitor the IUD position immediately after insertion, after 6 weeks, and later on at intervals of 6 months. The observation period included 3631 cycles.

RESULTS

We detected a significantly lower number of dislocations in LNG-IUD users. Previous expulsion was associated with a significantly higher risk for a re-expulsion in both IUD groups. Hypermenorrhea was not associated with an increased dislocation rate in LNG-IUD users.

CONCLUSION

Expulsions are less likely to occur with the LNG-IUD, which might contribute to its contraceptive efficacy.

Use of three-dimensional ultrasound in evaluating the intrauterine position of a levonorgestrel-releasing intrauterine system

This paper reports the first case of three-dimensional (3-D) transvaginal ultrasonography (TVS) imaging of malpositioned levonorgestrel-releasing intrauterine system (LNG-IUS). In patients carrying LNG-IUS, the application of 3-D TVS with the adjunctive volume contrast imaging in the coronal plane (VCI-C) and inversion rendering modes clearly display the correct spatial position of the LNG-IUS in relation to the uterine cavity much better than two-dimensional ultrasound.

Spontaneous upward movement of lowly placed T-shaped IUDs

OBJECTIVE

To assess the possible progression of intrauterine devices (IUDs) to a lower or upper position in women.

MATERIAL AND METHODS

Thirty-two lowly placed T-shaped IUDs in women with 0-3 children were examined with transvaginal ultrasonography after 2 months of insertion in order to assess the possible progression of the IUDs. Also, the IUDs inserted in women with 0-3, 0-1 and 2-3 children were compared to determine whether this progression was different depending on parity.

RESULTS

Intrauterine devices (97%, 100% and 93.7%) in the group of women with 0-3, 0-1 and 2-3 children, respectively, moved upward. The mean decrease in IUD-fundus distance was 6.8, 7.4 and 4.9 mm, respectively.

CONCLUSION

Lowly inserted T-shaped IUDs tend to move upward after insertion. Therefore, initial concern about low placement of a T-shaped IUD is not justified as most of them spontaneously readjust their position.

Transvaginal ultrasonographic assessment of the expulsion rate of intrauterine devices inserted in the immediate postpartum period: a pilot study

OBJECTIVE

To compare the expulsion rates of intrauterine devices (IUDs) inserted in the immediate postpartum after vaginal birth and cesarean section.

METHODS

Nineteen patients who had a vaginal birth and 19 patients who had a cesarean section at Hospital de Clínicas de Porto Alegre, Brazil, were selected for copper T 380A IUD insertion. With the aim of detecting clinically unnoticed dislodged devices, ultrasound examinations were performed at 1 month and between 3 and 12 months after delivery. The IUDs were considered completely expelled when found outside the endometrial cavity (e.g., in the cervical canal) or outside the uterus (in the vagina).

RESULTS

Expulsion rates were statistically different between the two groups: after a vaginal birth, 50% (ultrasound only) + 27.8% (clinical examination); and post-cesarean section, 0% (p < .001; OR 5.75, 95% CI 2.36-14.01).

CONCLUSION

Considering that the contraceptive efficacy of IUDs is associated with their intrauterine location, the high expulsion rates seen when they are inserted immediately after vaginal delivery contraindicate their use in this setting. The use of IUDs immediately after a cesarean section is still a reasonable alternative because its expulsion rate was zero. Ultrasound assessment of IUD positioning performed better than clinical examination, which failed to detect expulsion after postpartum insertion in 75% of the cases (9 from 12 cases).

Follow-up visits after IUD-insertion: sense or nonsense? A technology assessment study to analyze the effectiveness of follow-up visits after IUD insertion

The objective of this study is to evaluate whether regular follow-up after insertion of an IUD protects against the risk and side effects of this contraceptive device. To study the effectiveness of the follow-up visits done after IUD insertion, we compared a group of women with regular follow-up visits (group A: after 6 weeks, 3, 6 and 12 months) with women who had non-regular follow-up visits (group B: after 6 weeks and annually) for pregnancy, expulsion rates and discontinuation. A total of 280 women were included (group A: 199, group B: 81). Three pregnancies and 2 unnoticed expulsions were observed. The detection rate of an unnoticed expulsion is 0.35 and 0.11 per 100 visits for, respectively, the visit 6 weeks after insertion and all successive visits. Women in group A came significantly more frequently for unscheduled visits [relative risk (RR): 1.6; 95% confidence interval (CI): 1.03-2.4]. The number of discontinuations, pregnancies and expulsions did not differ between groups, but women in group B had their IUD removed earlier (p < 0.01). We conclude that regular follow-up after the insertion of an IUD is not effective.

T-shaped IUDs accommodate in their position during the first 3 months after insertion

The objective of this study was to observe the position dynamics of the T-shaped intrauterine device (IUD) in the uterine cavity, from insertion to 90 days of use. IUD position was evaluated in 214 women by vaginal ultrasound, measuring the IUD-endometrium, IUD-myometrium, and IUD-fundus distances. The 90th percentile of the IUD-endometrium distance was 5, 6, and 8 mm at time of insertion, 30 and 90 days of use; 7, 9, and 10 mm for IUD-myometrium distance; and 23, 24, and 27 mm for IUD-fundus distance, respectively. Seventeen IUDs were classified as misplaced at insertion by using the 90th percentile of the IUD-myometrium distance as standard. Of these, only 6 remained misplaced after 90 days of use. On the other hand, 21 IUDs were beyond the 90th percentile at the 90-day observation, only 6 of which were considered misplaced at insertion. We conclude that the T-shaped IUD accommodates its position in the uterine cavity during the first 3 months following insertion, and that ultrasound evaluation of its position is not a good predictor of future evaluation.

No relationship between the IUD position evaluated by ultrasound and complaints of bleeding and pain

The objectives of this study were to define the "normal" position of the T-shaped intrauterine device (IUD) in the endometrial cavity, using transvaginal ultrasound, and to compare the IUD's position in women with and without complaints of bleeding and/or pain. Vaginal ultrasound was carried out in women who had used a T-Cu 200 or T-Cu 380 for at least 6 months. Of these women, 236 registered bleeding complaints and/or pain and 245 had no complaints. The distances, IUD-endometrium, IUD-myometrium, and IUD-fundus, were measured in each woman. Our results showed that women with and without complaints presented no significant differences in age, parity, type of IUD, duration of use, previous contraceptive method used, hysterometry, uterine position, or period of the cycle in which the ultrasound was performed. The values of the three distances in users without complaints were widely dispersed. The 90th percentile of the IUD-endometrium, IUD-myometrium, and IUD-fundus distances were 7, 11, and 27 mm, respectively. The curve of the values for the three distances among women with complaints was similar to that of the subjects without complaints. Using the generally accepted measurement of 20 or 25 mm as the limits of normality of the distance IUD-fundus, and the 90th percentile of the distance IUD-endometrium as the gold standard, 77% and 43% of the women were false positives for "incorrect IUD position." Similar results were obtained when the 90th percentile of the distance IUD-myometrium was used as a gold standard. We concluded that the 90th percentiles of the distance IUD-endometrium, IUD-myometrium, and IUD-fundus were 7, 11 and 27 mm, respectively, among users without complaints. The ultrasonographic diagnosis of the IUD position was unable to discriminate between women who did or did not have complaints of bleeding and/or pain. If ultrasound were to be performed in T-shaped IUD users, the IUD-myometrium distance is likely to be the most reliable measurement.