Health during prolonged use of levonorgestrel 20 micrograms/d and the copper TCu 380Ag intrauterine contraceptive devices: a multicenter study. International Committee for Contraception Research (ICCR).

OBJECTIVES

To measure and compare the incidence of adverse events during use of two medicated intrauterine devices (IUDs).

DESIGN

A multicenter prospective 7-year randomized study.

SETTING

Family planning clinics, primarily in developing countries.

SUBJECTS

Women age 18 to 38 years at admission, desiring contraception and without contraindications to IUDs.

MAIN OUTCOME MEASURES

Incidence of complaints, conditions, and rates of specific termination for each IUD.

METHODS

Subjects recorded menstrual events, and clinical staff registered all complaints and conditions found on examination at four first-year clinic visits and at semiannual visits thereafter. Difference in rates were analyzed by chi 2 statistics.

RESULTS

Annual pregnancy rates for each IUD averaged 0.2/100 women whereas upper genital tract infection occurred at rates of 0.6 to 0.7 per 100 years of use. The levonorgestrel-releasing IUD significantly decreased bleeding and spotting days in comparison with historical data for noncontraceptors and with the copper-medicated IUD. Dysmenorrhea, vaginitis, and myoma in women with the levonorgestrel IUD were markedly decreased in comparison with the experience of copper IUD users. Significantly higher rates of amenorrhea, delayed ovarian follicular atresia, skin and hair conditions, and headache were observed with the steroid IUD than with the copper-releasing IUD. Rates of reported adverse effects for either IUD were highest in the first 2 years of use and among women under age 25.

CONCLUSIONS

Long-term use of copper or levonorgestrel IUDs is characterized by very low rates of pregnancy and by a low and declining annual incidence of side effects, including pelvic infection and borderline anemia. The levonorgestrel-releasing IUD reduced the incidence of bleeding and, in the long term, of myoma and myoma-related surgery in comparison with the copper T IUD. Both IUDs proved highly acceptable and had few unanticipated side effects.