Primary Tubal Infertility in Relation to the Use of an Intrauterine Device
Authors: Janet R. Daling, Noel S. Weiss, Barbara J. Metch, Wong Ho Chow, Richard M. Soderstrom, Donald E. Moore, Leon R. Spadoni, Bruce V. Stadel
Journal: New England Journal of Medicine (1985)

Women who use an intrauterine device (IUD) are at increased risk of acute pelvic inflammatory disease, but the relation of the IUD to subsequent infertility is not established. We interviewed 159 nulligravid women with tubal infertility to determine their prior use of an IUD. Their responses were compared with those of a matched group who conceived their first child at the time the infertile women started trying to become pregnant. The risk of primary tubal infertility in women who had ever used an IUD was 2.6 times that in women who had never used one (95 per cent confidence interval, 1.3 to 5.2). The observed difference between cases and controls was not uniform for different types of IUD. The relative risk associated with use of a Dalkon Shield was 6.8 (1.8 to 25.2), and that associated with use of either a Lippes Loop or Saf-T Coil IUD was 3.2 (0.9 to 12.0). The smallest elevation in risk was found among users of copper-containing IUDs (relative risk, 1.9 [0.9 to 4.0] for all women who had ever used a copper-containing IUD). The relative risk for women who used only a copper-containing IUD was 1.3 (0.6 to 3.0). We conclude that use of the Dalkon Shield (and possibly of plastic IUDs other than those that contain copper) can lead to infertility in nulligravid women.This study compared the contraceptive histories of 159 nulligravid women with tubal infertility with those of matched group of 159 controls who conceived their 1st child at the time the infertile women began attempting pregnancy. Results were adjusted for the confounding effects of cigarette smoking, number of sexual partners, and income. A higher percentage of cases (35%) than controls (14%) reported ever-use of an IUD (relative risk, 2.6; 95% confidence interval, 1.3-5.2.). The relative risk associated with use of the Daklon shield was 6.8 (1.8-25.2) and that associated with use of either the Lippes Loop or Saf-T-Coil was 3.2 (0.9-12.0). The smallest elevation of risk was noted among users of copper-containing IUDs, 1.9 (0.9-4.0); the relative risk for women who used only a copper IUD was 1.3 (0.6-3.0). The relative risk to tubal infection in women with a history of IUD-related pelvic inflammatory disease was 3.0 compared with women who had no history of such disease. The risk of tubal infection associated with an IUD in women with no prior or subsequent history of pelvic inflammatory disease was 2.6 (1.2-5.5). These results strongly suggest that the elevated risk of tubal infection observed in Dalkon Shield users reflects a casual relationship. The relatioonship. The relationship of tubal infection to the prior use of other types of IUDs is less clear, however. There is a possibility that the association noted between the use of Lippes Loop or Saf-T-Coil and tubal infertility may have been due to chance since the number of users of these devices in this sample was small. In addition, generalizations drawn from these results should be restricted to nulligravid women; the influence of IUD use on subsequent fertility may differ between women who have not been previously pregnant.