Some models are effective longer than any other reversible family planning method.
Correctly inserted, IUDs are safe for women at low risk of sexually transmitted disease. In fact, because IUDs prevent pregnancy so well, they save many lives. Effective for the Long Term Large international comparisons continue to collect evidence that IUDs are both safe and effective for long periods of time. The TCu-380A is now the most widely available IUD and one of the most effective methods of contraception ever developed. In large studies fewer than one woman per 100 became pregnant in the first year of use and, in the longest comparative study, only 2.1 per 100 became pregnant in 10 years of use.