Cardiac Rehabilitation

Abstract

Copper Intrauterine Devices and Tubal Infertility among Nulligravid WomenTo the Editor: Hubacher and colleagues (Aug.23 issue) 1 report that the use of copper intrauterine devices (IUDs) is not associated with an increased risk of tubal occlusion among nulligravid women.However, only 6 percent of the women in the study had used an IUD.Accordingly, the numbers used to test for an effect of the duration of IUD use, an extremely important aspect of the study, were even smaller.Only 44 women had used a copper IUD for more than one year, of whom only 8 had tubal occlusion.Nevertheless, the odds ratios for tubal occlusion show a moderate, nonsignificant trend of increasing risk with increasing duration of IUD use (up to 6 months, 0.8 [95 percent confidence interval, 0.4 to 1.8]; 7 to 12 months, 1.1 [95 percent confidence interval, 0.4 to 2.8]; and 13 months or more, 1.3 [95 percent confidence interval, 0.6 to 3.2]).The upper limits of these confidence intervals are consistent with a marked effect of longer duration of IUD use on tubal infertility.We believe that the authors' conclusion that contemporary copper IUDs are safe is unwarranted.In a study of women using IUDs, mostly devices containing copper, we reported no deleterious effect on fertility of short-term use (up to 42 months) but strong evidence of such an effect after longterm use (78 months or more). 2 The study by Hubacher et al. cannot rule out an adverse effect of these devices and should be interpreted with caution.