Health effects of long-term use of the intrauterine levonorgestrel-releasing system. A follow-up study over 12 years of continuous use.

BACKGROUND

This report comprises women from one center, who all participated in a larger European multi-center study, which included 2758 healthy women, of whom 1821 were randomly allocated to the levonorgestrel-releasing intrauterine system (Lng-IUS) and 937 to a copper-IUD (Nova-T). At the end of the 5 year study period, 109 of the 300 women, who originally were allocated to the Lng-IUS at this center, were still using the Lng-IUS. The women were offered the opportunity to continue the Lng-IUS and 100 women chose to do so. After a total period of almost 7 years of continuous use, a second Lng-IUS was offered and 82 of the women chose to start a second segment of Lng-IUS use. After another 5 years, 69 of the women were fitted with their third Lng-IUS.

METHODS

These 82 women were examined yearly throughout the study period and bleeding pattern, hemoglobin, weight, blood-pressure, general well-being and intercurrent disease were analyzed to assess long-term effects.

RESULTS

No pregnancy occurred during the follow-up. One case of partial expulsion occurred and one case of pelvic inflammatory disease. Seventy-seven percent of the women did not report any health problems at all during the entire follow-up period of 13 years. At the end of the second period with the Lng-IUS, 60% reported amenorrhea, 12% infrequent, scanty bleeds and 28% regular, scanty bleeds. As a consequence, the hemoglobin values increased, with a mean increase, after 12-13 years, being 1.35 g/dl. Blood pressure increased slightly and body weight increased with a mean increase of 0.49 kg/year. Seven women became postmenopausal during the follow-up and started estrogen replacement therapy with the Lng-IUS in situ.

CONCLUSIONS

This follow-up study suggests that the Lng-IUS remains a safe and effective method of contraception, allowing women prolonged relief of menstrual problems, and for women in their late reproductive years, offering a convenient and bleeding-free transition into the menopause.