Assessment of copper corrosion from frameless copper IUDs after long-term in utero residence

Re-evaluation of the existing health-based guidance values for copper and exposure assessment from all sources

Copper is an essential micronutrient and also a regulated product used in organic and in conventional farming pest management. Both deficiency and excessive exposure to copper can have adverse health effects. In this Scientific Opinion, the EFSA 2021 harmonised approach for establishing health-based guidance values (HBGVs) for substances that are regulated products and also nutrients was used to resolve the divergent existing HBGVs for copper. The tightly regulated homeostasis prevents toxicity manifestation in the short term, but the development of chronic copper toxicity is dependent on copper homeostasis and its tissue retention. Evidence from Wilson disease suggests that hepatic retention is indicative of potential future and possibly sudden onset of copper toxicity under conditions of continuous intake. Hence, emphasis was placed on copper retention as an early marker of potential adverse effects. The relationships between (a) chronic copper exposure and its retention in the body, particularly the liver, and (b) hepatic copper concentrations and evidence of toxicity were examined. The Scientific Committee (SC) concludes that no retention of copper is expected to occur with intake of 5 mg/day and established an Acceptable Daily Intake (ADI) of 0.07 mg/kg bw. A refined dietary exposure assessment was performed, assessing contribution from dietary and non-dietary sources. Background copper levels are a significant source of copper. The contribution of copper from its use as plant protection product (PPP), food and feed additives or fertilisers is negligible. The use of copper in fertilisers or PPPs contributes to copper accumulation in soil. Infant formula and follow-on formula are important contributors to dietary exposure of copper in infants and toddlers. Contribution from non-oral sources is negligible. Dietary exposure to total copper does not exceed the HBGV in adolescents, adults, elderly and the very elderly. Neither hepatic copper retention nor adverse effects are expected to occur from the estimated copper exposure in children due to higher nutrient requirements related to growth.

Effective easing of the side effects of copper intrauterine devices using ultra-fine-grained Cu-0.4Mg alloy

Copper intrauterine device is one of the most adopted contraceptive methods with high effectiveness (over 99 %), low cost, spontaneous reversibility and long-lasting usage. However, the side effects induced from the initial burst release of copper ions (Cu²⁺) hinder the continuation of the Cu-IUD made of Coarse-Grained Copper (CG Cu). We proposed to tailor the bio-corrosion behaviors of better control of Cu²⁺ release via the addition of bioactive Mg into the Ultra-Fine Grained (UFG) Bulk Cu. Thus, UFG bulk Cu with 0.4 wt.% Mg was produced via equal-channel angular pressing. The microstructures of the UFG Cu-0.4Mg was observed using electron backscatter diffraction and transmission electron microscopy techniques. The in vitro long-term corrosion behaviors in simulated uterine fluid, cytotoxicity to four cell lines, in vivo biocompatibility and contraceptive efficacy were all studied on CG Cu, UFG Cu and UFG Cu-0.4Mg materials. The results demonstrate that both the ultrafine grains and the addition of bioactive Mg into Cu contribute to the suppression of the burst release of Cu²⁺ in the initial stage and the maintenance of high level Cu²⁺ in long-term release. Moreover, the UFG Cu-0.4Mg also exhibited much improved cell and tissue biocompatibility from both the in vitro and in vivo evaluations. Therefore, the contraceptive efficacy of UFG Cu-0.4Mg is still maintained as high as the CG Cu and UFG Cu while the side effects are significantly eased, suggesting the high potential of the UFG Cu-0.4Mg alloy as a new upgrading or alternative material for Cu-IUD. STATEMENT OF SIGNIFICANCE: The side effects from burst release of Cu²⁺ at the initial implantation stage of Cu-containing intrauterine devices (Cu-IUD) is one of the main drawbacks of these devices. In this work, an ultra-fine-grained Cu (UFG Cu) alloyed with a low amount of bioactive Mg was used for a Cu-IUD. The UFG Cu-0.4Mg alloy exhibited suppressed burst release of Cu²⁺ at initial implantation, while active Cu²⁺ release for long-term usage was maintained, comparable to coarse-grained pure Cu. Furthermore, the UFG Cu-0.4Mg alloy displayed significantly improved biocompatibility with human uterus cells and a much decreased inflammatory response within the uterus. Therefore, the side effects from Cu-IUD were eased, while high antifertility efficacy of the UFG Cu-0.4Mg alloy was maintained. The UFG Cu-0.4Mg alloy is promising for Cu-IUD.

Long-term indwelling copper intrauterine device (IUD) found during primary infertility work up

Infertility is a public health concern worldwide. Hysterosalpingogram is a useful diagnostic tool to both evaluate the contours of the uterine cavity and to assess tubal patency. Intrauterine devices (IUDs) are the world's most prevalent form of long-acting reversible contraception. In this case, a 30-year-old P0 female, an immigrant from Jamaica, was referred for hysterosalpingogram for primary infertility workup. Under fluoroscopic imaging, an unexpected T-shaped IUD was visualized in the expected location of the uterus. The IUD lacked portions of the radiopaque copper lining. The patient initially denied IUD insertion. However, after further investigation, the patient's mother admitted IUD insertion at the age of 14 in Jamaica. This case raises a concern for the possibility of unexpected IUD discovery during infertility work up and emphasizes the importance of clinician awareness of the changes that may be seen on imaging when these devices are in place long-term.

XMaS @ the ESRF

This paper describes the motivation for the design and construction of a beamline at the European Synchrotron Radiation Facility (ESRF) for the use of UK material scientists. Although originally focused on the study of magnetic materials, the beamline has been running for 20 years and currently supports a very broad range of science as evidenced by the research topics highlighted in this article. We describe how the beamline will adapt to align with the ESRF's upgrade to a diffraction limited storage ring. This article is part of the theme issue 'Fifty years of synchrotron science: achievements and opportunities'.

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.