Correspondence
Copper Intrauterine Devices and Tubal Infertility among Nulligravid Women
N Engl J Med 2002; 346:376-377January 31, 2002
- Article
To 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 long-term 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.
2 ReferencesMartin P. Vessey, M.D.
Helen A. Doll, M.Sc.
University of Oxford, Oxford OX3 7LF, United Kingdom1
Hubacher D ,Lara-Ricalde R ,Taylor DJ ,Guerra-Infante F ,Guzman-Rodriguez R . Use of copper intrauterine devices and the risk of tubal infertility among nulligravid women. N Engl J Med 2001;345:561-567
Full Text | Web of Science | Medline2
Doll H ,Vessey M ,Painter R . Return of fertility in nulliparous women after discontinuation of the intrauterine device: comparison with women discontinuing other methods of contraception. BJOG 2001;108:304-314
CrossRef | Web of Science | Medline
To the Editor:
Hubacher and colleagues conclude that the previous use of a copper IUD is not associated with tubal occlusion, whereas chlamydia infection is. However, inserting a “safe” IUD into a woman with an active chlamydial infection can spread the infection to the upper genital tract, resulting in pelvic inflammatory disease. Hubacher et al. argue that an IUD is suitable for women who are not likely to be at risk for sexually transmitted diseases, but chlamydia is common and is often unrecognized. The problem is greater when an IUD is used for postcoital contraception and there is no opportunity for screening. In our opinion, there is no reason to pardon the IUD.
Veronique Verhoeven, M.D.
Dirk Avonts, M.D., Ph.D.
Lieve Peremans, M.D.
University of Antwerp, 2610 Wilrijk, Belgium
verover@uia.ua. ac. be Author/Editor Response
The authors reply:
To the Editor: Vessey and Doll state that long-term use of copper IUDs may impair fertility. We disagree that our case–control study did not include enough long-term use of the IUD to show this putative effect. Vessey and Doll cite odds ratios based on data from the control group of infertile women; however, if their reasoning were applied to our second control group of primigravid women, they might have concluded that the longer a woman uses a copper IUD, the less likely she is to become infertile. With these women serving as controls, the odds ratios for tubal occlusion associated with IUD use of 6 months or less, 7 to 12 months, and 13 or more months were 1.4 (95 percent confidence interval, 0.6 to 3.6), 1.0 (95 percent confidence interval, 0.3 to 3.0), and 0.6 (95 percent confidence interval, 0.3 to 1.4), respectively. On the basis of the interpretation of our data and the research of others,1,2 we stand by our conclusion that copper IUDs do not impair fertility.
Chlamydia is common and often goes unrecognized, as Verhoeven and colleagues state, but withholding the IUD is not the answer if a woman says she is in a mutually monogamous relationship and has no clinical signs or symptoms of genital tract infection. In Belgium,3 the rates of cervical chlamydial infections in women who opted for an IUD were far lower than the rates in women who used oral contraceptives (presumably as a result of a combination of self-selection and careful screening). Perhaps, then, the fear with regard to chlamydia is misdirected. At the time of insertion of the IUD, bacteria can be pushed into the upper genital tract; though they require validation, clinical studies indicate that the rates of pelvic inflammatory disease, even in the presence of cervical infection, are within or below the reported ranges without IUD insertion.4 Even when sexually transmitted diseases are more prevalent, the increased risk of pelvic inflammatory disease attributable to IUD insertion is estimated to be very low (about 1 in 667).5 Blaming the IUD for problems that require a bacterial pathogen is misleading. We believe that decisions about contraception should be based on the best available evidence, rather than on clinical opinion. A growing body of literature indicates that IUD use is far safer than previously thought.
5 ReferencesDavid Hubacher, Ph.D.
Family Health International, Research Triangle Park, NC 27709
dhubacher@fhi.org Roger Lara-Ricalde, M.D.
Instituto Nacional de Perinatologia, Mexico City 11000, Mexico1
Skjeldestad F ,Bratt H . Fertility after complicated and non-complicated use of IUDs: a controlled prospective study. Adv Contracept 1988;4:179-184
CrossRef | Medline2
Wilson JC . A prospective New Zealand study of fertility after removal of copper intrauterine contraceptive devices for conception and because of complications: a four-year study. Am J Obstet Gynecol 1989;160:391-396
Web of Science | Medline3
Avonts D ,Sercu M ,Heyerick P ,Vandermeeren I ,Meheus A ,Piot P . Incidence of uncomplicated genital infections in women using oral contraception or an intrauterine device: a prospective study. Sex Transm Dis 1990;17:23-29
Web of Science | Medline4
Grimes DA . Intrauterine device and upper-genital-tract infection. Lancet 2000;356:1013-1019
CrossRef | Web of Science | Medline5
Shelton JD . Risk of clinical pelvic inflammatory disease attributable to an intrauterine device. Lancet 2001;357:443-443
CrossRef | Web of Science | Medline
