Rossing M A, Daling J R, Voigt L F, Stergachis A S, Weiss N S
Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle.
Epidemiology. 1993 May;4(3):252-8. doi: 10.1097/00001648-199305000-00009.
Using data from a population-based, case-control study, we assessed risk of tubal pregnancy associated with use of an intrauterine device (IUD) at the time of conception. Cases were 249 members of Group Health Cooperative of Puget Sound who experienced a tubal pregnancy between 1981 and 1986. Controls were 831 members at risk of ectopic pregnancy who were similar to cases with respect to age and county of residence, but otherwise selected at random. Risk of tubal pregnancy associated with current IUD use was compared separately to that among users of various other (or no) contraceptive methods. Tubal pregnancy was more likely to occur among IUD users than among women using oral contraceptives [relative risk (RR) = 3.8, 95% confidence interval (CI) = 1.5-9.9] or barrier methods (RR = 3.6, 95% CI = 1.6-8.1), or, to a lesser extent, among women who had been surgically sterilized (RR = 1.6, 95% CI = 0.8-3.5). In contrast, IUD users were much less likely to experience a tubal pregnancy (RR = 0.2, 95% CI = 0.1-0.4) than were women who were currently not contracepting. For most women, the decision to use an IUD occurs within the context of choosing among various contraceptive methods. Our results indicate that, for these women, the decision to use an IUD results in increased risk of ectopic pregnancy while the device is in use.
利用一项基于人群的病例对照研究数据，我们评估了受孕时使用宫内节育器（IUD）与输卵管妊娠风险之间的关联。病例为普吉特海湾健康合作组织的249名成员，他们在1981年至1986年间经历了输卵管妊娠。对照为831名有异位妊娠风险的成员，他们在年龄和居住县方面与病例相似，但其他方面是随机选取的。将当前使用IUD的输卵管妊娠风险与使用其他各种（或不使用）避孕方法的人群的风险分别进行比较。IUD使用者发生输卵管妊娠的可能性高于使用口服避孕药的女性[相对风险（RR）= 3.8，95%置信区间（CI）= 1.5 - 9.9]或屏障避孕法的女性（RR = 3.6，95% CI = 1.6 - 8.1），在较小程度上也高于接受过绝育手术的女性（RR = 1.6，95% CI = 0.8 - 3.5）。相比之下，IUD使用者发生输卵管妊娠的可能性（RR = 0.2，95% CI = 0.1 - 0.4）远低于当前未采取避孕措施的女性。对于大多数女性而言，使用IUD的决定是在多种避孕方法的选择背景下做出的。我们的结果表明，对于这些女性来说，使用IUD的决定会导致在使用该装置期间异位妊娠风险增加。
