Hormonal IUD Users Experience Fewer Side Effects and Pregnancy Rates as Low as Copper IUD Users

Abstract

A comparative study involving 2226 women in a 7-year trial (beginning in 1981) of the experimental levonorgestrel-releasing IUD revealed that users of the hormone-releasing IUD experience less bleeding and spotting than users of the Copper T IUD while being equally protected against pregnancy. In addition the hormonal IUD appeared to protect against the development of benign uterine myomas. The average duration of use of the hormonal IUD was 3.04 years (3416 woman-years) vs. 3.55 years for the copper IUD (3975 woman-years). By the end of the study the cumulative gross pregnancy rates were 1.1/100 for the hormonal IUD and 1.4/100 for the copper IUD. Average annual pregnancy rates were 0.16/100 and 0.18/100 respectively. No ectopic pregnancies were associated with the hormonal IUD and 2 occurred in women using the copper IUD. The actual number of days of bleeding or spotting in women using the hormonal device declined from 50 in the first year of the study to 30 in the fourth year. Copper T users averaged 70 days of bleeding and spotting per year. Hormonal users were also less likely to complain of menstrual pain; however hormonal users were more likely to discontinue the method because of absence of bleeding (Copper T users were more likely to discontinue because of heavy bleeding). Menstrual complaints of all kinds diminished over time in the hormonal users. Hormonal users were less likely to have vaginitis but more likely to have ovarian follicular cysts than Copper T users. Hormonal users were also more likely to have acne headaches dizziness nausea and vomiting. The researchers concluded that the hormonal IUD is an attractive alternative to the Copper T.