An evaluation of the levonorgestrel-releasing IUD: its advantages and disadvantages when compared to the copper-releasing IUDs

Abstract

The levonorgestrel-releasing IUD (LNG-IUD-20), providing a daily dose of 20 ug, has recently been approved for marketing in Finland. The IUD's high efficacy in preventing accidental pregnancy and other numerous positive features make it a promising contraceptive device for worldwide use, just like the currently available T-shaped copper-releasing (TCu) IUDs. This paper reviews published reports comparing the LNG-IUD-20 and the currently used TCu IUDs. The merits and disadvantages of the steroid-releasing IUD are evaluated in terms of its performance and other special features relative to the TCu IUDs. Also, a number of future studies with medical and programmatic importance are proposed. A broader understanding about these two IUD families will facilitate their use in a complementary way for family planning programs.

PIP: This literature review compares the merits and disadvantages of the levonorgestrel-releasing IUD made by Leiras Pharmaceuticals, Turkey, Finland (LNG-IUD-20), with the Nova-T, Copper-T (TCu) and 220C, and Copper-T-38-Ag (TCu-380Ag). This IUD releases 20 mcg levonorgestrel daily from a Silastic sleeve on the vertical shaft containing 52 mg. The plasma level stabilized after a month at about 0.2 ng/ml, about half as high as that seen with Norplant implants. It is identical in size to the Nova-T. The Cu-T IUDs differ with respect to copper wire or sleeves, or silver-cored wire. The chief studies reviewed here were 2 multi-center trails primarily in European countries, and a 2 large multi-center trials in India. Cumulative pregnancy rates were 0.0 to 0.6 per 100 users for the LNG IUD, compared to slightly higher failures for inert or copper IUDs. While removal rates for bleeding, pain and pelvic inflammatory disease were lower for the LNG-IUD-20, removals for oligomenorrhea, amenorrhea and hormonal side effects were higher than for the other IUDS. In the Indian trials, removals for amenorrhea and irregular bleeding were much higher than rates reported in the European studies, resulting in significantly lower continuation rates overall. The results pointed to district benefits for the LNG-IUD-20, such as lower blood loss and anemia, relief of dysmenorrhea and menorrhagia, as well as possible lower risks of ectopic pregnancy in case of failure, less PID (pelvic inflammatory disease), and the claim by the maker that strictly correct placement is not necessary. Disadvantages of the LNG-IUD-20 are more difficult insertion due to the wider diameter; oligomenorrhea, amenorrhea and irregular bleeding; hormonal side effects such as acne, weight gain, nausea, headache and breast tension; and potential risk of functional ovarian cysts. The LNG-IUD-20 is considered comparable to copper IUDs in effectiveness, safety, longevity, and return to fertility after removal. Users should be counseled that the oligomenorrhea or amenorrhea is neither a medical problem or indicative of infertility, is common for the 1st 2 months, is reversible on removal, may signal an improved hemoglobin profile, relief of dysmenorrhea, and may be preferred to heavy bleeding from other IUDS. The program implications of this IUD are potential lower incidence of ectopic pregnancy and PID. The effect of its use on breast feeding, cost-effectiveness compared to Norplant, in-country manufacture, and cultural acceptance need to be determined in specific locales.