Long-term experience with Norplant contraceptive implants in Finland.

Silastic implants containing the progestin, levonorgestrel, were tested as a long-term contraceptive system in 124 women. During five years of use no accidental pregnancy occurred. The first year continuation rate was 90% and the five-year continuation rate was 54%, including terminations for wish to become pregnant. The medically relevant continuation rate was 68% after five years. Menstrual irregularities were the most frequent reason for termination, but only in the first two years. 70% of the terminations for that reason occurred during the first two years. Terminations for other steroid-related reasons were infrequent. The follow-up will continue up to the end of the seventh year. Seven of seventeen women who requested removal of the implants because they wanted to become pregnant conceived during the first two cycles and only three were not pregnant one year after removal.